Korean Air Flight 801 - Aircraft Accident Report (NTSB)/Factual Information

by National Transportation Safety Board

1. Factual Information

1.1 History of Flight

On August 6, 1997, about 0142:26 Guam local time,^[1] Korean Air flight 801, a Boeing 747-3B5B (747-300), Korean registration HL7468, operated by Korean Air Company, Ltd., crashed at Nimitz Hill, Guam.^[2] Flight 801 departed from Kimpo International Airport, Seoul, Korea, with 2 pilots, 1 flight engineer, 14 flight attendants, and 237 passengers^[3] on board. The airplane had been cleared to land on runway 6 Left at A.B. Won Guam International Airport, Agana, Guam, and crashed into high terrain about 3 miles southwest of the airport. Of the 254 persons on board, 228 were killed,^[4], and 23 passengers and 3 flight attendants survived the accident with serious injuries.^[5] The airplane was destroyed by impact forces and a postcrash fire. Flight 801 was operating in U.S. airspace as a regularly scheduled international passenger service flight under the Convention on International Civil Aviation and the provisions of 14 Code of Federal Regulations (CFR) Part 129 and was on an instrument flight rules (IFR) flight plan.

According to Korean Air company records, the flight crew arrived at the dispatch center in the Korean Air headquarters building in Seoul about 2 hours before the scheduled departure time of 2105 (2005 Seoul local time) on August 5, 1997. The original flight plan for flight 801 listed a different captain's name. The captain aboard the accident flight had initially been scheduled to fly to Dubai, United Arab Emirates; however, because the accident captain did not have adequate rest for that trip, he was reassigned the shorter trip to Guam.^[6]

According to Korean Air personnel, the flight crewmembers collected the trip paperwork, conducted a self-briefing, and received a briefing from the assigned supervisor of flying (SOF).^[7] Flight 801 departed the gate about 2127 and was airborne about 2153. According to the cockpit voice recorder (CVR), the captain was performing the pilot-flying (PF) duties, and the first officer was performing the pilot-not-flying (PNF) duties. Upon arrival to the Guam area, the first officer made initial contact with the Federal Aviation Administration's (FAA) Guam Combined Center/Radar Approach Control (CERAP) controller about 0103:18, when the airplane was level at 41,000 feet mean sea level (msl) and about 240 nautical miles (nm) northwest of the NIMITZ VOR/DME.^[8]

About 0105:00, the CERAP controller told flight 801 to expect to land on runway 6L, and the first officer acknowledged the transmission. About 0110:00, the controller instructed flight 801 to "...descend at your discretion maintain two thousand six hundred [feet msl]." The first officer responded, "...descend two thousand six hundred pilot discretion."

About 0111:51, the CVR^[9] recorded the captain briefing the first officer and the flight engineer about the approach and landing at Guam. The captain stated:

I will give you a short briefing...ILS [instrument landing system^[10]] is one one zero three...NIMITZ VOR is one one five three, the course zero six three, since the visibility is six, when we are in the visual approach, as I said before, set the VOR on number two and maintain the VOR for the TOD [top of descent],^[11] I will add three miles from the VOR, and start descent when we're about one hundred fifty five miles out. I will add some more speed above the target speed. Well, everything else is all right. In case of go-around, since it is VFR [visual flight rules], while staying visual and turning to the right...request a radar vector...if not, we have to go to FLAKE^[12]...since the localizer glideslope is out,13 MDA [minimum descent altitude] is five hundred sixty feet and HAT [height above touchdown] is three hundred four feet....

About 0113:33, the CVR recorded the captain saying, "we better start descent;" shortly thereafter, the first officer advised the controller that flight 801 was "leaving four one zero for two thousand six hundred." The controller acknowledged the transmission.

The CVR recorded the captain making several remarks related to crew scheduling and rest issues. About 0120:01, the captain stated, "if this round trip is more than a nine hour trip, we might get a little something...with eight hours, we get nothing...eight hours do not help us at all."^[13] The captain also stated that "they make us work to maximum, up to maximum...." About 0120:28, the captain further stated, "probably this way [unintelligible words], hotel expenses will be saved for cabin crews, and maximize the flight hours. Anyway, they make us [747] classic guys work to maximum." ^[14] About 0121:13, the captain stated, "eh...really...sleepy."

About 0121:59, the first officer stated, "captain, Guam condition is no good." About 0122:06, the CERAP controller informed the flight crew that the automatic terminal information service (ATIS) information Uniform^[15] was current and that the altimeter setting was 29.86 inches of mercury (Hg). About 0122:11, the first officer responded, "Korean eight zero one is checked uniform;" his response did not acknowledge the altimeter setting. About 0122:26, the captain stated, "uh...it rains a lot." About 0123:45, the captain stated, "request twenty miles deviation later on...to the left as we are descending." About 0124:02, the first officer questioned, "don't you think it rains more? in this area, here?" The captain then stated, "left, request deviation" and "one zero mile." About 0124:30, the controller approved the first officer's request to deviate "...one zero mile left of track [for weather]."

The CVR then recorded about 6 minutes of discussion among the flight crew regarding the weather conditions and the deviation around the weather. About 0126:25, the flight engineer stated, "it's Guam, Guam." About 0131:17, the first officer reported to the CERAP controller that the airplane was "...clear of Charlie Bravo [cumulonimbus clouds]" and requested "radar vectors for runway six left." The controller instructed the flight crew to fly a heading of 120?. After this transmission, the flight crew performed the approach checklist and verified the radio frequency for the ILS to runway 6L. About 0138:49, the CERAP controller instructed flight 801 to "...turn left heading zero nine zero join localizer;" the first officer acknowledged this transmission. At that time, flight 801 was descending through 2,800 feet msl with the flaps extended 10? and the landing gear up.

About 0139:30, the first officer said, "glideslope [several unintelligible words]...localizer capture [several unintelligible words]...glideslope...did." About 0139:44, the controller stated, "Korean Air eight zero one cleared for ILS runway six left approach...glideslope unusable."^[16] The first officer responded, "Korean eight zero one roger...cleared ILS runway six left;" his response did not acknowledge that the glideslope was unusable.

According to the CVR, about 0139:55 the flight engineer asked, "is the glideslope working? glideslope? yeh?" One second later, the captain responded, "yes, yes, it's working." About 0139:58, an unidentified voice in the cockpit stated, "check the glideslope if working?" This statement was followed 1 second later by an unidentified voice in the cockpit asking, "why is it working?" About 0140:00, the first officer responded, "not useable."

About 0140:06, the CVR recorded the sound of the altitude alert system^[17] chime. According to information from the flight data recorder (FDR), the airplane began to descend about 0140:13 from an altitude of 2,640 feet msl at a point approximately 9 nm from the runway 6L threshold (5.7 nm from the NIMITZ VOR). About 0140:22, an unidentified voice in the cockpit said, "glideslope is incorrect." About 0140:33, as the airplane was descending through 2,400 feet msl, the first officer stated, "approaching fourteen hundred [feet]." About 4 seconds later, when the airplane was about 8 nm from the runway 6L threshold, the captain stated, "since today's glideslope condition is not good, we need to maintain one thousand four hundred forty [feet]. please set it." An unidentified voice in the cockpit then responded, "yes." About 0140:42, the CERAP controller instructed flight 801 to contact the Agana control tower; the first officer acknowledged the frequency change. The first officer contacted the Agana tower about 0140:55 and stated, "Korean air eight zero one intercept the localizer six left." Shortly after this transmission, the CVR again recorded the sound of the altitude alert chime, and the FDR data indicated that the airplane was descending below 2,000 feet msl at a point 6.8 nm from the runway threshold (3.5 nm from the VOR). About 0141:01, the Agana tower controller cleared flight 801 to land.

About 0141:14, as the airplane was descending through 1,800 feet msl, the first officer acknowledged the landing clearance, and the captain requested 30? of flaps. No further communications were recorded between flight 801 and the Agana control tower.

About 0141:31, the first officer called for the landing checklist. About 0141:33, the captain said, "look carefully" and "set five hundred sixty feet" (the published MDA). The first officer replied "set," the captain called for the landing checklist, and the flight engineer began reading the landing checklist. About 0141:42, as the airplane descended through 1,400 feet msl, the CVR recorded the sound of the ground proximity warning system (GPWS)^[18] radio altitude callout "one thousand [feet]." One second later, the captain stated, "no flags gear and flaps," to which the flight engineer responded, "no flags gear and flaps." About 0141:46, the captain asked, "isn't glideslope working?" There was no indication on the CVR that the first officer and flight engineer responded to the this question. About 0141:48, the captain stated, "wiper on."^[19] About 0141:53, the CVR recorded the sound of the windshield wipers starting. The windshield wipers remained on throughout the remainder of the flight.

About 0141:53, the first officer again called for the landing checklist, and the flight engineer resumed reading the checklist items. About 0141:59, when the airplane was descending through 1,100 feet msl at a point about 4.6 nm from the runway 6L threshold (approximately 1.3 nm from the VOR), the first officer stated "not in sight?" One second later, the CVR recorded the GPWS radio altitude callout of "five hundred [feet]." According to the CVR, about 2 seconds later the flight engineer stated "eh?" in an astonished tone of voice.

About 0142:05, the captain and flight engineer continued the landing checklist. About 0142:14, as the airplane was descending through 840 feet msl and the flight crew was performing the landing checklist, the GPWS issued a "minimums minimums" annunciation followed by a "sink rate" alert^[20] about 3 seconds later. The first officer responded, "sink rate okay" about 0142:18; FDR data indicated that the airplane was descending 1,400 feet per minute at that time.

About 0142:19, as the airplane descended through 730 feet msl, the flight engineer stated, "two hundred [feet]," and the first officer said, "let's make a missed approach." About 1 second later, the flight engineer stated, "not in sight," and the first officer said, "not in sight, missed approach." About 0142:22, as the airplane descended through approximately 680 feet msl, the FDR showed that the control column position began increasing (nose up) at a rate of about 1? per second, and the CVR indicated that the flight engineer stated, "go around." When the captain stated "go around" about 1 second later, the airplane's engine pressure ratios and airspeed began to increase. However, the rate of nose-up control column deflection remained about 1° per second. At 0142:23.77, as the airplane descended through 670 feet msl, the CVR recorded the sound of the autopilot disconnect warning. At 0142:24.05, the CVR began recording sequential GPWS radio altitude callouts of "one hundred...fifty...forty...thirty...twenty [feet]." About 0142:26, the airplane impacted hilly terrain at Nimitz Hill, Guam, about 660 feet msl and about 3.3 nm from the runway 6L threshold. FDR data indicated that, at the time of initial ground impact, the pitch attitude of the airplane was increasing through 3°. The accident occurred at 13? 27.35 minutes north latitude and 144? 43.92 minutes east longitude during the hours of darkness. The CVR stopped recording about 0142:32.

Figure 1 shows the instrument approach chart for the Guam runway 6L ILS procedure that was in effect at the time of the accident. Figures 2 and 3 show FDR information for the last 5 ? minutes of flight, along with CVR comments and sounds and air traffic control (ATC) data.

A non-free image has been removed from this page.

Figure 1. Instrument approach chart for the Guam International Airport runway 6L ILS procedure.
Reproduced with the permission of Jeppesen Sanderson, Inc. NOT TO BE USED FOR NAVIGATION.

Figure 2. Side view of FAA radar data with selected ATC and CVR communication excerpts.

Figure 3. Overhead view of FAA radar data with selected ATC and CVR communication excerpts.

1.2 Injuries to Persons

Table 1. Injury chart.

Injuries	Flight Crew	Cabin Crew	Passengers	Other	Total
Fatal	3	11	214	0	228
Serious	0	3	23	0	26
Minor	0	0	0	0	0
None	0	0	0	0	0
Total	3	14	237	0	254

1.3 Damage to Airplane

The airplane was destroyed by impact forces and a postcrash fire. The estimated value of the airplane was about $60 million.

1.4 Other Damage

The accident caused extensive ground scarring and fire damage to trees and foliage along the wreckage path and in the immediate vicinity of the main wreckage area. Also, a 12-inch fuel oil pipeline located along a vehicle access road that services the NIMITZ VOR was severed when it was struck by the airplane. The severed pipeline spilled about 1,000 gallons of oil in a localized area.

1.5 Personnel Information

1.5.1 The Captain

The captain, age 42, was hired by Korean Air on November 2, 1987. He was previously a pilot in the Republic of Korea Air Force. He held an Airline Transport Pilot (ATP) certificate issued by the Korean Ministry of Construction and Transport (MOCT)^[21] on April 19, 1992, with type ratings in the Boeing 727 and 747. The captain qualified as a 727 first officer on December 19, 1988, and as a 747 first officer on February 13, 1991. He upgraded to 727 captain on December 27, 1992, and 747 captain on August 20, 1995. The captain held Korean and FAA First Class Airman Medical certificates, both issued on March 13, 1997, without limitations.

According to Korean Air records, the captain had accumulated a total of 8,932 hours of flight time, 2,884 hours as a military pilot and 6,048 hours as a civilian pilot. He had logged a total of 1,474 and 1,718 hours as a 747 first officer and captain, respectively. Also, Korean Air's 747 chief pilot stated, in a post accident interview, that the captain had received a Flight Safety Award in May 1997 from the company president for successfully handling an in-flight emergency involving a 747 engine failure at a low altitude.

The captain had flown 235, 144, 90, and 17 hours in the last 90, 60, 30, and 7 days, respectively, before the accident. Between December 1992 and August 1993, he had flown from Seoul to Guam eight times as a 727 captain. In addition, he had flown from Seoul to Guam as a 747 captain on July 4, 1997 (about 1 month before the accident). National Transportation Safety Board investigators interviewed the first officer from the July 4, 1997, flight. That first officer stated that the captain had contacted him by telephone 1 day before the trip and proposed that they obtain a charter briefing for Guam because they did not regularly conduct 747 operations at that airport. Consequently, the captain and first officer arrived several hours before the trip departure time and received a charter briefing from a Korean Air instructor, even though the briefing was not required. The captain and first officer watched the Guam airport familiarization video presentation^[22] and studied the approach charts for the airport. During that time, the captain commented that the area where the NIMITZ VOR is located was mountainous and required extra attention (referring to this area as a "black hole"). The first officer said the trip to Guam was routine and that the weather was good, with scattered cumulous clouds and good visibility at the airport. Further, the first officer said that the captain briefed and executed the ILS 6L approach to a routine landing.^[23]

The captain's last route check was on a round trip flight from Seoul to Narita, Japan, on July 19, 1997. A company check airman told Safety Board investigators that, although the weather conditions at Narita and Seoul were above instrument approach minimums, the captain executed the full ILS approach to each airport and received an "above standard" evaluation for the flights. The captain's last proficiency check was conducted in a Korean Air 747 simulator on June 11, 1997. According to Korean Air, the captain executed a nonprecision VOR/DME approach to runway 32L at Kimpo Airport during the proficiency check. The simulated weather conditions for the approach were 900 feet overcast and winds 290? at 11 knots. The captain received an "excellent" evaluation. A Korean Air representative told Safety Board investigators that the captain had passed the company's Level 3 Pilot English Test^[24] and had attended crew resource management (CRM) training from October 24 to 27, 1989. The captain had not flown with the flight 801 first officer before the accident flight.

Korean Air records indicated that the captain flew a round trip flight sequence from Seoul to San Francisco, California, from July 28 to July 30, 1997. He was off-duty until August 2, when he flew two round trip domestic flights between the hours of 1100 and 2000.^[25] On August 3, the captain flew an international trip to Hong Kong that arrived in the early evening. The return flight was delayed because of inclement weather. The captain remained in Hong Kong overnight and flew back to Seoul the next morning, arriving about 1230. After the accident, the captain's wife told Safety Board investigators, through a family representative, that the captain normally awoke between 0600 and 0630 and went to bed between 2200 and 2300. She stated that, on August 2, the captain awoke between 0600 and 0630 and went to bed about 2300. On August 3, the captain awoke about 0630 for the trip to Hong Kong and remained there overnight. The captain's wife stated that, after arriving home on August 4 from the trip, he was involved in routine activities and went to bed at his accustomed time. According to the captain's wife, on August 5, he awoke at 0600, worked out in a gym for an hour and returned home for breakfast. He later studied the flight schedule for the trip to Guam, took a nap from 1100 to 1340, and then ate lunch. She also stated that the captain departed for the 20-minute drive to Kimpo Airport about 1500 and that the captain had left early to allow time to prepare for the flight to Guam.

1.5.2 The First Officer

The first officer, age 40, was hired by Korean Air on January 10, 1994. He was previously a pilot in the Republic of Korea Air Force. He held an ATP certificate issued by the FAA on July 10, 1994, and a Korean ATP certificate issued by the MOCT on March 28, 1997. He received a 747 type rating on March 11, 1995, and qualified as a 747 first officer on July 23, 1995. The first officer held Korean and FAA First Class Airman Medical certificates, both issued on June 13, 1997, with no limitations. According to company records, the first officer had accumulated a total of 4,066 hours of flight time, 2,276 hours as a military pilot and 1,790 hours as a civilian pilot. He had logged a total of 1,560 hours as a 747 first officer. The first officer had flown 189, 132, 67, and 20 hours in the last 90, 60, 30, and 7 days, respectively, before the accident. The first officer had flown from Seoul to Guam in August and September 1995 as a 747 first officer. According to company records, he viewed the Guam airport familiarization video on July 8, 1997, in preparation for a future flight to Guam. The first officer's last route check was conducted in July 1995. The first officer's last proficiency check was conducted in a Korean Air 747 simulator on March 28, 1997. During the proficiency check, the first officer executed a nonprecision VOR/DME approach to runway 32L at Kimpo Airport. The simulated weather conditions for the approach were clouds 900 feet broken and winds 260° at 11 knots. An instructor noted, in an overall simulator session evaluation, that the first officer's "control skills and knowledge [were] above standard." The first officer received a "standard" evaluation for his nonprecision VOR approaches. However, the instructor noted that the "altitude management on nonprecision approach [was] somewhat less than desirable." Another instructor noted that the first officer was "somewhat slow to carry out directions." According to Korean Air records, the first officer had passed the Level 3 Pilot English Test but had not attended CRM training.

Korean Air records indicated that the first officer returned from an international trip to the United States on the afternoon of August 2, 1997. He was off-duty on August 3 and flew a round trip domestic flight on August 4, 1997, between 0930 and 1245. The first officer was then off-duty until the accident flight. Safety Board investigators interviewed the first officer's relatives after the accident. They stated that he telephoned his mother about 1700 on August 5 and that "everything seemed routine." Because his family lived in New Zealand, the first officer's relatives could not be specific about his activities before the accident flight.

1.5.3 The Flight Engineer

The flight engineer, age 57, was hired by Korean Air on May 7, 1979. He was previously a navigator in the Republic of Korea Air Force. He obtained his flight engineer's certificate on December 29, 1979, and was qualified on the Boeing 727 and 747 and Airbus A300 airplanes. The flight engineer held a Korean First Class Airman Medical Certificate issued on June 5, 1997. According to company records, the flight engineer had accumulated a total of 13,065 hours of flight time, including 11,088 hours as a flight engineer (1,573 hours of which were as a flight engineer on the 747). Korean Air records also indicated that the flight engineer had flown 165, 120, 77, and 28 hours in the last 90, 60, 30, and 7 days, respectively, before the accident.

The flight engineer's last two route checks were in April 1997. He received an "above standard" evaluation for the first route check and an "excellent" evaluation for the second route check. The flight engineer's last proficiency check was in a Korean Air 747 simulator on March 7, 1997. He received an "above standard" evaluation for the session, and an instructor note stated, "control skills and knowledge are above standard." The flight engineer's crew coordination was also rated as "above standard." According to Korean Air records, the flight engineer passed the Level 3 Pilot English Test and attended CRM training from April 28 to May 1, 1987. A Korean Air official indicated that the flight engineer had never flown to Guam.

The flight engineer had returned to Seoul on August 3, 1997, after completing a 3-day international trip to Anchorage, Alaska, and San Francisco. Although he was off-duty on August 4 and was assumed to have engaged in routine activities at home, the flight engineer's wife and son could not provide Safety Board investigators with details of his activities or sleep patterns before the accident flight.

1.5.4 The Flight Attendants

Fourteen flight attendants were working on the accident flight. The lead flight attendant (or purser), age 37, had been hired by Korean Air on July 18, 1988. According to company records, the purser had completed her basic training on August 28, 1988, and her most recent recurrent training was completed on December 10, 1996.

One flight attendant, age 43, was hired by Korean Air in August 1981; the other 12 flight attendants, ranging in age from 21 to 25, were hired between November 1992 and March 1997. According to company records, all had completed their basic training, and their most recent recurrent training was completed between June 1996 and April 1997.

1.5.5 The Air Traffic Controllers

1.5.5.1 Combined Center/Radar Approach Control

The CERAP controller, age 39, was hired by the FAA on May 30, 1982, in Los Angeles, California, and initially qualified as a terminal radar approach control (TRACON) controller. He transferred to the Guam CERAP facility on September 3, 1995,^[26] where he was certified as a full-performance level controller. Before his employment with the FAA, the controller worked as a radar and tower controller in the U.S. Navy. His last duty station in the Navy was at Naval Air Station Cubi Point, Philippines, from 1978 to 1982. He was medically certified as a controller without waivers or limitations.

1.5.5.2 Air Traffic Control Tower The Agana tower controller, age 39, was hired by Barton ATC International, Inc.-- a nonfederal contract ATC service company--as an air traffic controller at the Guam Federal Control Tower on May 15, 1995.^[27]

According to company and FAA records, the controller was fully certified on all positions of operations in the tower, including clearance delivery, ground control, local control, and controller-in-charge. He was medically qualified for his duties and held an FAA Second Class Airman Medical Certificate issued on April 9, 1997, without waivers or limitations. Before his employment with Barton ATC International, the controller held a similar position in the U.S. Navy from 1983 to 1992. During this time, the controller was trained and qualified in various TRACON positions, including radar approach control, arrival radar, radar final, departure radar, and precision and surveillance radar. He was assigned to the Naval Air Station Agana tower in 1989. The controller told Safety Board investigators that, at the Agana Naval tower, he was qualified in all tower positions and worked as a flight data controller, radar final controller, tower supervisor, facility watch supervisor, and radar branch chief. The controller remained on Guam after he was discharged from the Navy.

1.6 Airplane Information

The accident airplane, HL7468, serial number 22487, was one of three Boeing 747-300s in Korean Air's fleet. The airplane was delivered new to the company on December 12, 1984, and had been operated and maintained continuously by Korean Air until the accident. Every Korean-registered aircraft is subject to annual renewal of its airworthiness certificate from the Korean Civil Aviation Bureau (KCAB); this airplane's last airworthiness certificate was issued on July 7, 1997.

At the time of the accident, the airplane had accumulated about 50,105 hours total time in service and about 8,552 cycles.^[28]The airplane was equipped with four Pratt & Whitney JT9D-7R4G2 engines with total times and cycles since new of 26,014 hours and 4,699 cycles (No. 1), 36,611 hours and 6,137 cycles (No. 2), 25,904 hours and 4,383 cycles (No. 3), and 33,889 hours and 5,701 cycles (No. 4). The most recent engine change before the accident was the replacement of the No. 3 engine on June 11, 1997, after a compressor surge incident.

According to Korean Air, the airplane was maintained according to the company's Continuous Maintenance Program, which was approved by the KCAB. The maintenance program comprised "A" checks performed at 350-hour intervals and "C" checks at 4,000-hour intervals. (Approximately 12 A checks are performed between each C check.) The last A check was performed on July 12, 1997, at 49,874 hours. The last C check was performed on December 16, 1996, at 47,918 hours. During the C check, operational/functional test work cards were completed for the transponders, radar altimeters, VOR/ILS navigation receivers, central air data computers, GPWS, autopilot, automatic direction finder (ADF), altitude alert, inertial navigation systems, weather radar, DME, and high-frequency radios. Further, the FDR was read out, and the altimeters were calibrated.

1.6.1 Maintenance Discrepancies Before the Accident Flight

The accident airplane's logbooks indicated that, from December 1996 (the time of the last C check) to August 1997, all mechanical discrepancies identified by flight crews or maintenance personnel had been corrected before the next scheduled flight. Several discrepancies were deferred, in accordance with Korean Air minimum equipment list guidelines, and the airplane was flown to Seoul for repair. The airplane's logbook entries during this time period detailed the following maintenance deficiencies and corrective actions:

• Between December 18, 1996, and January 5, 1997, five airspeed-related writeups were logged, including one that identified a discrepancy of up to 50 knots between the captain's and first officer's airspeed indicators while in cruise. Corrective actions were taken.
• On April 9, 1997, the GPWS failed the "below glideslope" test. Contamination was cleaned from a connector.
• Between May 3, 1997, and June 23, 1997, six writeups were logged about erroneous fuel quantity indications on the No. 1 fuel quantity indicator. The system was checked after each event.
• On July 3, 1997, the first officer's altimeter was replaced.

• On July 30, 1997, during an autocoupled approach at Seoul, autopilot channel "A" disengaged at a radar altitude of 1,000 feet. (According to a Boeing representative, because the autopilot is a triple-redundant system, it would have continued to control the airplane using the "B" and "C" channels.) A pin on one of the autopilot system's electrical connectors was subsequently cleaned.

Korean Air records indicated that the accident airplane had no deferred maintenance items when it was dispatched on August 5, 1997, and that no discrepancies had been identified in the airplane's logbook for the previous 12 flights. The partially completed logbook page for the accident flight was recovered from the wreckage, and no maintenance writeups had been logged.

1.6.2 Cockpit Instrumentation

The captain's and first officer's instrumentation panels from the Boeing 747 Classic are shown in figures 4 and 5, respectively. A discussion of the accident airplane's autopilot system, GPWS, and ILS follows.

1.6.2.1 Autopilot System

The accident airplane was equipped with a Sperry-Rand (now Rockwell Collins) autopilot, model SPZ1. The autopilot system consists of a mode control panel and three pitch and roll computers (with a landing rollout function) that drive the pitch and roll actuators. In addition, two separate yaw damper computers provide control to the "split" rudder system (two individual rudder panels).

Boeing engineers stated that, when the autopilot's ILS mode is selected by the pilot and a sufficient glideslope signal exists, the glideslope "armed" indicator is annunciated in the cockpit with an amber light. The pitch and roll computers maintain pitch control and operate in any of the following modes: "Altitude Hold," "Altitude Select," "Indicated Airspeed Hold," or "Vertical Speed." When the deviation of the glideslope signal reaches a predetermined level, the vertical beam sensor automatically switches the landing rollout computer function to control the pitch axis of the elevator. The glideslope signal is

A non-free image has been removed from this page.

Figure 4. Captain's instrumentation panel.
Reproduction courtesy of The Boeing Company.

A non-free image has been removed from this page.

Figure 5. First officer's instrumentation panel.
Reproduction courtesy of The Boeing Company.

validated before the system can arm the glideslope "engage" logic and the vertical beam sensor. According to Boeing, if the glideslope signal is invalid, the failure will be annunciated in the cockpit with a steady red "autopilot" warning light. The altitude alert system is coupled to the autopilot.

The altitude alert is armed by the pilot when the desired altitude is set into the "ALT SEL" (altitude select) window on the pilot's control panel (or glareshield). The amber "ALTITUDE ALERT" light illuminates steadily, and a 2-second aural tone sounds when the aircraft is approaching the selected altitude from either 900 feet above or below. The light remains illuminated until the aircraft is within 300 feet of the desired altitude. The light then flashes, and the 2-second aural tone sounds when the aircraft deviates 300 feet above or below the selected altitude until the deviation exceeds 900 feet, at which time the light extinguishes and the system automatically resets for subsequent altitude alerting. The "deviation from altitude" mode of the altitude alert system deactivates when the landing gear is extended.

1.6.2.2 Ground Proximity Warning System

The accident airplane was equipped with an AlliedSignal Mark VII GPWS Warning Computer.^[29] The mode 2 warnings "TERRAIN" and "PULL UP" were desensitized^[30] during flight 801's approach while the airplane was in the landing configuration (gear down/flaps extended). The advisories and alerts that remained active in the landing configuration were those for excessive descent rate (sink rate); excessive terrain closure rate; excessive glideslope deviation; minimums (radio altitude decision height) callout; and 1,000, 500, 100, 50, 40, 30, 20, and 10 feet radio altitude callouts.^[31]

On October 3, 1997, postaccident testing of the GPWS installed on flight 801 was performed at AlliedSignal facilities in Redmond, Washington. The testing found that the GPWS was capable of normal operation. 1.6.2.3 Instrument Landing System The accident airplane was equipped with three Rockwell International/Collins Model 51RV-5B ILS receivers. No recorded malfunctions or abnormalities with the three receivers were recorded between the time of their respective installations (from November 1996 to May 1997) and the accident.

In a normally functioning system, ILS information is displayed in the cockpit on the captain's and first officer's raw data indicators on the attitude director indicator (ADI) and the horizontal situation indicator (HSI) if they are receiving localizer and glideslope information. In addition, the ADI's flight directors (FD) display ILS information if the appropriate FD mode is selected.^[32] The ADI and HSI are equipped with a warning flag that is displayed over the ILS indications (localizer and glideslope) to alert a pilot if either the ground or airborne system fails or if the receivers are not set to the correct radio frequency.^[33]

According to the manufacturer, the glideslope warning flag will appear if the navigation receiver is tuned to an ILS frequency and any of the following conditions exist:

• there is an absence of a glideslope radio-frequency signal or 90- and 150-Hertz (Hz) modulations;
• the percentage of modulation of either the 90- or 150-Hz signal is reduced to zero and the other is sustained at 40 percent or more; or
• the level of a standard glideslope deviation signal produces 50 percent or less of the standard deflection of the deviation indicator.

1.6.3 Weight and Balance

The weight and balance form signed by the captain and the dispatcher for the accident flight included the following data:^[34]* zero fuel weight, 197,897 kilograms (kg);

• departure fuel, 51,847 kg;
• trip fuel, 36,923 kg;
• takeoff weight, 249,744 kg;
• estimated landing weight, 212,821 kg;
• passenger weight (including cabin baggage), 17,694 kg;
• cargo in compartments, 7,333 kg;
• takeoff weight center of gravity, 24 percent mean aerodynamic cord; and
• takeoff stabilizer trim setting, 4.4 units.

1.7 Meteorological Information

1.7.1 Weather Conditions at Guam International Airport

Guam's climate is relatively uniform throughout the year. Guam averages 247 days each year with measurable amounts of precipitation (rain), and most days begin with scattered layers of clouds that become broken to overcast by afternoon.

From August to October, visual meteorological conditions (VMC) prevail about 80 percent of the time, and instrument meteorological conditions (IMC) prevail predominately during the afternoon hours. The rainy season lasts from July to November. During that time, precipitation averages about 24 days per month, and the prevailing winds are usually from the east, averaging about 9 knots.

A weather synopsis prepared by the Guam National Weather Service (NWS) Office on the day of the accident stated:

...a weak low pressure trough is moving slowly [through] the Mariana Islands...resulting in gentle to moderate easterly winds and scattered showers. The effects of the upper level low far to the northeast have diminished during the past 12 hours or so. Light to moderate showers should be expected except for isolated afternoon thunderstorms due to solar heating.

About 0122:06 during the accident flight, the flight crew was informed by the CERAP controller that ATIS information Uniform was current. The content of that report was as follows:

Agana tower information UNIFORM, time one four five zero zulu, wind calm, visibility seven, [clouds] one thousand six hundred scattered, two thousand five hundred scattered, temperature two seven [Celsius], dew point two four, altimeter two niner eight six, runway six in use. NOTAMs [Notices to Airmen^[35]], runway six left ILS glideslope out of service until further notice, advise on contact you have information UNIFORM.

The special surface weather observation for 0132 on August 6, 1997, was as follows:

Wind 090? at 6 knots; visibility--7 miles; present weather--shower vicinity; sky condition--scattered 1,600 feet, broken 2,500 feet, overcast 5,000 feet;^[36] temperature--27? C; dew point--25? C; altimeter setting 29.85 inches Hg; remarks--showers vicinity northwest-northeast.

The special surface weather observation for Guam International Airport for 0147 on August 6 was as follows:

Wind variable at 4 knots; visibility--5 miles; present weather--light rain shower; sky condition--few 1,500 feet, scattered 2,500 feet, overcast 4,000 feet; temperature 26° C; dew point 24° C; altimeter 29.85 inches Hg.

The Safety Board examined the NWS surface weather observation logs and found that heavy rain showers were reported at the airport between 0020 and 0029, between 0114 and 0116, and between 0153 and 0158. The weather logs also indicated that light rain showers were reported at the airport between 0016 and 0020, between 0029 and 0033, between 0106 and 0114, between 0116 and 0128, and between 0138 and 0148. Further, light rain and mist were also reported between 0148 and 0153. The maximum windspeed recorded at the airport between 0130 and 0150 was about 10 knots.

The following terminal aerodrome forecast (TAF) for Guam International Airport, which was issued by the NWS on August 6 at 0030 as an amendment to an earlier TAF, was valid at the time of the accident:

Wind 120° at 7 knots, visibility greater than 6 miles, scattered 1,600 feet scattered 4,000 feet scattered 8,000 feet overcast 30,000 feet. Temporary August 6, 0100 to August 6, 0600, wind 130° at 12 knots gusting 20 knots, visibility 3 miles, heavy rain shower, broken 1,500 feet cumulonimbus overcast 4,000 feet.

The radar antenna of the Guam Weather Surveillance Radar-1988, Doppler (WSR-88D) was located about 5 nm east of the accident site. Data recorded about 0143 on August 6 (1543 UTC time on August 5, 1997) indicated an area of precipitation over higher terrain about 4 nm southwest of the airport, including Nimitz Hill. The precipitation was oriented east to west, about 7 to 8 nm long and 3 to 4 nm wide, and was moving toward the west. Figure 6 shows the WSR-88D four-panel base reflectivity product for 0143.

1.7.2 Air Traffic Control Weather Information

The CERAP radar controller stated that, although areas of weather were in the vicinity of the VOR and airport, he had not received any pilot reports from midnight to the time of the accident. The controller stated that a "relatively small cell,"38 which he believed to be of light to moderate intensity, was depicted on the Airport Surveillance Radar (ASR)-8 display. Further, the controller said that the "relatively small cell"^[37] observed on radar extended about 3 to 5 miles on the final approach course and was about 2 to 3 miles across in the largest area. The controller said that he had no means of determining the intensity of this or any other weather cell because, unlike other weather radar displays, the ASR-8 radar display is monochromatic, and it is difficult to differentiate precipitation intensity without color. However, the controller also said that he

Figure 6. WSR-88D four-panel base reflectivity product for Guam.

interpreted the intensity of precipitation by the different levels of opaque (white) shading and his experience as a controller.

The CERAP controller stated that he did not advise the flight crew or the Agana tower controller that he had observed the precipitation on radar while flight 801 was on the approach course to the airport. The controller said that he had assumed that the flight crew was using cockpit radar because they had asked him twice for deviations around weather. The controller stated that the airplane's cockpit radar was more accurate and more precise than the radar he was using at the CERAP. The controller further stated that he did not observe (on radar) the airplane entering the precipitation.

FAA Order 7110.65, "Air Traffic Control," paragraph 2-6-4 (a) states that a controller is to "issue pertinent information on observed/reported weather or chaff39 areas. Provide radar navigational guidance and/or approved deviations around weather or chaff^[38] when requested by the pilot...." Paragraph 2-6-4 (c) states that a controller is to "inform any tower for which you provide approach control services if you have any weather echoes on radar which might affect their operations." Further, paragraph 2-9-2 states that, in the event of "rapidly changing conditions," a new ATIS is to be recorded and that the information is to be issued by ATC.

The Agana tower controller stated that, although it was not raining at the airport when flight 801 was inbound, a rain shower was moving in from the northeast over the airport and down the runway to the southwest. The tower controller said that he did not know when the rain began at the airport because he was using binoculars to try to locate flight 801 on the approach. He estimated that the visibility was 7 miles and stated that no low clouds were visible.

1.7.3 Additional Weather Information

A certified Navy weather observer on Nimitz Hill, about ¾ mile northwest from the accident site, stated that the cloud ceiling about the time of the accident was approximately 700 to 800 feet above ground level (agl), or 1,300 to 1,400 feet msl, during a heavy rain shower. Also, he stated that visibility was about 200 to 300 meters and that the windspeed was not more than 10 knots. The NWS forecaster on duty at the time of the accident stated that no SIGMETs [Significant Meteorological Information] were valid for Guam and that the night was "pretty routine." The flight crew of Continental Air Micronesia flight 960, a Boeing 747 that landed at Guam about 30 minutes before the accident, stated that visibility was "excellent" from PAYEE intersection (located about 240 nm north of the NIMITZ VOR) and that scattered thunderstorms were occurring around the area. Further, the pilots indicated that their on-board radar depicted rain showers over the NIMITZ VOR but not over the airport. They also stated the visibility was "good" under 2,000 feet and that they maintained visual contact with the airport throughout the approach.

The flight crew of Ryan International flight 789, which landed shortly after the accident occurred, stated that the visibility was sufficient to see the lights of Guam from about 150 nm away. The first officer stated that on-board weather radar indicated showers northeast of the airport but no thunderstorms.

Additionally, the Ryan flight crew initially requested a visual approach when the flight was about 15 nm from the VOR, but the airplane encountered clouds and rain on approach to runway 6L shortly thereafter. The first officer stated that the airplane remained in the clouds until it was in proximity of the VOR, at which time the airplane broke out and the flight crew was able to acquire and maintain visual contact with the airport. The captain stated that, although clouds and rain were over the island's shoreline, the air around the airport and in the vicinity of the accident site was smooth. Further, the captain, who was also a check airman based at Guam, said that he "noticed that once [flight] crews are given a visual approach [to Guam International Airport] they have a tendency to press on even when they lose visual contact in hopes of regaining visual contact again.... That's because so many approaches are visual and the clouds and rain showers are so localized."

In addition, a witness who was hunting on Nimitz Hill at the time of the accident stated that it was not raining when he observed flight 801 pass over his position (100 feet north of the VOR beacon) and crash a very short distance away. He said that there had been intermittent rain showers shortly before the accident but that, when he saw the airplane crash, he could see stars directly over the accident site. The witness also said that the visibility was "very good" at the time of the accident and that, although he could not see the airport lights, he could see the lights of the town of Tamuning (3 to 4 miles northeast of his location). He said that the wind was "normal" and that no thunder or lightning was in the area.

1.8 Aids to Navigation

Guam International Airport is serviced by three navigational aids: the NIMITZ VOR/DME (UNZ); the Mount Macajna nondirectional beacon (NDB), which was not operational at the time of the accident; and the ILS glideslope and localizer.

The colocated VOR and DME transmitters were equipped with a "selfmonitoring" system that samples radiated transmitter signals to ensure that the system is operating within prescribed tolerances and parameters. If these tolerances are exceeded, the monitoring system automatically shuts down the equipment. According to the facility logs, the VOR was not shut down at the time of the accident.

On the day of the accident, the FAA conducted a flight check of the localizer, outer marker, and NDB at Guam. The VOR and DME at Guam were not checked by the FAA until the day after the accident because of rescue operations. The FAA's flight checks determined that the respective systems were functioning properly and within prescribed tolerances.^[39] The flight checks did not examine the glideslope because it was out of service and removed at the time (see section 1.10.2 for more information).

1.9 Communications

No communications problems were reported between the crew of flight 801 and any of the FAA or contract ATC facilities. (See sections 1.7.2 and 1.10.1 for more information.)

1.10 Airport Information

The A.B. Won Pat Guam International Airport is located about 3 nm northeast of Agana on the west-central coast of Guam at an elevation of 297 feet msl. The airport is leased to the Guam International Airport Authority by the U.S. Navy, and the associated navigational facilities are owned and operated by the FAA. The airport has two parallel runways oriented northeast/southwest: runway 6R/24L, which is 8,001 feet long and 150 feet wide, and runway 6L/24R, which is 10,015 feet long and 150 feet wide.

Runway 6L is equipped with high-intensity runway edge lights and a mediumintensity approach lighting system with runway alignment indicator lights.^[40] The runway was not equipped with runway end identifier lights, centerline lights, or touchdown zone lights. Runway 6L is also equipped with a four-box visual approach slope indicator (VASI) calibrated for a 3° visual glidepath angle. The touchdown elevation of runway 6L is 256 feet but rises to 297 feet at the departure end of the runway.

Guam International Airport was certified by the FAA as an Index D aircraft rescue and firefighting (ARFF) facility under 14 CFR Part 139. In accordance with this index, the airport is required to maintain a minimum of three ARFF vehicles capable of carrying a total quantity of at least 4,000 gallons of water.

1.10.1 Air Traffic Control Services for Guam International Airport

1.10.1.1 Combined Center/Radar Approach Control

The Guam CERAP, located at Andersen Air Force Base (AFB),^[41] provides both TRACON and en route ATC services. To do so, the CERAP is equipped with two independent radar data processing systems that receive radar information from different radar sites: terminal ATC services are provided by an Automated Radar Terminal System (ARTS) IIA analog display processor connected to an ASR-8 radar system; en route ATC services are provided by a digitized, narrow-band Micro-En route Automated Radar Tracking System (EARTS) processor connected to an FPS-93 long-range radar.^[42] Each of these systems independently performs its own minimum safe altitude warning (MSAW) processing (see section 1.10.1.2) but uses different algorithms that have been optimized for either terminal or en route operations. Both the FPS-93 and ASR-8 sensors are located about 1,500 feet apart on Mount Santa Rosa.

The CERAP airspace comprises concentric circles centered around the Mount Santa Rosa radar antenna site. The 250-nm-radius outer ring, which encompasses all of the airspace from above the surface, is classified as oceanic airspace. A 100-nm-radius inner ring, which extends over the Saipan radio beacon and from the surface to 28,000 feet, is classified as domestic airspace.^[43] The CERAP airspace is adjoined on all sides by the Oakland Air Route Traffic Control Center oceanic sectors. The airspace over Saipan and Guam is classified as approach control airspace, and its boundaries extend from the surface to 17,000 feet. The CERAP was classified as a Level II facility at the time of the accident.^[44]

The CERAP facility has two en route and one approach control radar positions. The R-1 en route radar position is responsible for the 100-nm inner circle; the R-4 en route radar position is responsible for the 250-nm outer circle. The D-3 approach control radar position, which is located between the en route R-1 and R-4 radar positions, is responsible for a 25-nm inner ring that extends from the surface to 17,000 feet and includes the NIMITZ VOR and the Andersen TACAN.^[45] At the time of the accident, one controller was performing the functions of all three positions from the R-4 position.

Authorized staffing for the Guam CERAP comprises 14 full-performance level controllers, 3 supervisors, an Automation Specialist, a Quality Assurance/Training Specialist, an Air Traffic Manager, and a secretary. According to FAA quality assurance staff at Guam, afternoon traffic at Guam is primarily overflights of aircraft traveling northbound, and evening traffic is primarily aircraft traveling inbound from Asia.

The CERAP controller on duty at the time of the accident told Safety Board investigators that, after arriving at the facility at 2345 on August 5, 1997, he assumed the duties at the R-4 en route radar position (and the colocated R-1 en route and D-3 approach control radar positions). A coworker arrived at the facility and assumed the duties at the D-3 position from midnight to 0110, at which time he went on a break. The controller then resumed the duties of the D-3 position. (His coworker was not in the control room at the time of the accident.)

The CERAP controller stated that he was monitoring the EARTS (en route) radar display, which was set to 265 nm (but normally covers 250 nm). The controller also said that the en route radar display (which was located directly in front of him) was set to show the MSAW area in the lower right corner. (Controllers are able to set radar information to any position on the radar screen.) According to the controller, the en route radar system was displaying only secondary radar (beacon) target information^[46] throughout his shift. (The system was set up that way when he relieved the previous controller on duty.) He said the en route radar system was not able to display weather information because the part of the system that would normally display such information was out of service.

Further, the CERAP controller told investigators that the TRACON radar display (which was located to his immediate right) was set to a 60-nm range. The controller also stated that the approach control radar was set to display the MSAW area in the lower center of the screen. In addition, the controller said that the approach control radar was displaying primary and secondary radar return targets^[47] and areas of weather that were moving through the Guam area throughout his shift.

The CERAP controller also told investigators that the traffic complexity and density, that is, the number of aircraft under his control, from the time of initial radio contact with flight 801 (about 0103:18) to the time he advised the flight crew to contact the Agana tower (about 0140:42) was "light to moderate traffic and routine complexity." The controller estimated that he was handling 10 to 15 aircraft during that time, including flight 801. After the CERAP controller initiated the communications change (instructing flight 801 to contact the Agana tower controller), he was still responsible for radar monitoring of the flight because the Agana tower was a VFR facility and none of the criteria for automatic termination of radar service, as stated in FAA Order 7110.65, "Air Traffic Control," paragraph 5-1-13, had been met. However, the CERAP controller was no longer able to directly contact the airplane after it had switched to the Agana tower frequency. During a postaccident interview, the controller stated that he did not monitor the progress of flight 801 after the communications changeover because he was performing other duties that might have precluded further monitoring. According to the transcript from the recorded voice communications of radio and interphone lines during the period that flight 801 was in communication with the Agana tower, the CERAP controller made a radio transmission to another aircraft about 0140:54. From about 0141:14 to 0141:30, he was on the interphone with a controller at the Oakland Center. About 0142:05, the CERAP controller acknowledged a transmission from the flight crew of Ryan International flight 789. The transcript indicated no further activity until about 0143:49, when the CERAP controller called the Agana tower with a flight plan. The CERAP controller said that he last observed the target of flight 801 on the terminal radar display when the airplane was 7 miles from the airport at an altitude of 2,600 feet.

Between 0150 and 0151, the CERAP controller was queried by the Agana tower controller about flight 801. About 0154:44, the CERAP controller contacted Ryan flight 789 and stated, "ryan seven eighty nine roger we may have lost an airplane...." About 0156:03, the CERAP controller requested the Ryan flight crew to "...look for signs of an accident west of the airport." About 0156:35, a Ryan flight crewmember advised the CERAP controller, "...about fifteen minutes ago we saw the clouds light up bright red it was kinda weird we thought it was just our eyes or something." About 0156:58, the crewmember advised the controller, "we got a big fireball on the hillside up here...about our three o'clock and two miles?ah a mile."

1.10.1.2 Minimum Safe Altitude Warning System

Beginning in 1977, MSAW functions were incorporated into the ARTS software installed in FAA terminal radar data processing systems.^[48] According to FAA technical document NAS-MD-684, MSAW provides general terrain monitoring for all aircraft, including those not on approach, within a predetermined geographic area and approach path monitoring for certain aircraft operating within an approach capture box (a rectangular area surrounding a runway and final approach course). The document also states that aircraft on approach are to be monitored based on their current or predicted altitude compared with the lowest MDA for the approach and that warning alerts are based on an "aircraft's relative position to a runway threshold and final approach course centerline."

The ARTS IIA MSAW system uses computer software that contains a terrain database customized for the environment around each airport that utilizes ARTS processors. The MSAW system is designed to visually and aurally alert a controller whenever an IFR-tracked target with an altitude encoding transponder (Mode C) descends below, or is predicted by the software to descend below, a predetermined safe altitude. The ARTS IIA and EARTS MSAW systems use approach capture boxes aligned with runway final approach courses to identify aircraft that are landing. Within these boxes, MSAW applies special rules specific to approach and landing operations. The ARTS IIA adaptation allows the use of a "pseudo-glideslope" that underlies the actual glideslope. Predicted or actual descent below this pseudo-glideslope normally produces a low-altitude alert. EARTS approach adaptation is less sophisticated and does not include glideslope monitoring; instead, a single base altitude is used for the entire approach capture box.

According to FAA records, the Guam terminal (approach) MSAW system was originally installed in 1990 to provide altitude protection within a 55-nm radius around the Guam ASR-8 site. In March 1993, a new software package was developed and evaluated by FAA technicians for installation at Guam. The new software was designed to inhibit MSAW alerts inside a 54-nm radius of the Guam ASR-8 site. Thus, the MSAW was only available (uninhibited) for a 1-mile radius (from 54 to 55 nm around the Guam ASR-8 site). According to FAA representatives, this change, designed as a temporary solution to reduce false, or "nuisance," warnings, was submitted by the Guam CERAP and approved by the FAA's Western Pacific Regional Office. The Safety Board requested documentation of the reasons for the changes, but the FAA was unable to explain the specific reason(s) for the change in the MSAW configuration.^[49] The FAA Technical Center in Atlantic City, New Jersey, modified the software and delivered it to Guam in January 1994, but the software did not become operational until February 1995. (The EARTS MSAW system at Guam only generates visual MSAW alerts, and these alerts were not inhibited at the time of the accident.)

The ARTS IIA system recorded no alerts for Korean Air flight 801 at any time. The EARTS MSAW alert records showed that a visual approach path warning was generated at 0142:20, about 6 seconds before the crash of flight 801, and continued until at least 0142:49.

At the Safety Board's public hearing,^[50] the FAA's Deputy Program Director of Air Traffic Operations testified that, in some circumstances, controller issuance of an MSAWbased safety alert could be a first-priority duty equal to separation of aircraft. FAA Technical Center management testified that MSAW is a safety-critical service.

An FAA quality assurance evaluation report, dated July 31, 1995, on the Guam CERAP facility stated that the MSAW system had been inhibited and that a NOTAM had been issued about the inhibited MSAW.^[51] An FAA representative stated that, because no "established policy" existed for MSAW operations at the time of the 1995 evaluation, the MSAW inhibition was noted only as an "informational" item in the evaluation team's report and, as a result, did not require corrective or follow-up action. The report also indicated that a new digital terrain map had been ordered and was scheduled for delivery in April 1995 but that the delivery date had been rescheduled for August 1995.

FAA documents revealed that new MSAW software became operational in April 1996, but it contained the same 54-nm-radius inhibition as the February 1995 version. About 1 year after the installation of the new software, the FAA conducted another facility quality assurance evaluation of the Guam CERAP. The evaluation report, dated April 1997, did not note that the ARTS IIA MSAW system remained inhibited.

According to the FAA, the MSAW system at Guam was restored to full, uninhibited operation on August 23, 1997 (17 days after the flight 801 accident), after the monitoring software parameters were adjusted to reduce false alert incidents.^[52] The FAA indicated that, since that time, controllers had been experiencing about 18 nuisance alarms per day and that work was ongoing to reduce these alarms.

1.10.1.3 Air Traffic Control Tower

The Agana tower is responsible for operations within the surrounding Class D airspace, which is defined as the airspace within a 5-statute mile radius from the center of the Guam International Airport up to, but not including, 2,500 feet agl. The tower facility is located on the south-southwest side of the airport and is operational 24 hours a day. The controller positions are arranged in a semicircular pattern that face generally from the southwest to the northeast. The four operational positions are the controller-in-charge, local control, ground control, and flight data. All of the positions are typically worked by one controller as a combined function, but the positions may be separated depending on traffic conditions and staffing levels.

In August 1994, Barton ATC International, Inc., was awarded the contract to provide ATC services at the Agana tower. Barton was purchased by Serco Aviation Services, Inc., in January 1997. According to a Serco official, 6 controllers with an average of 15 years of experience worked at the tower at the time of the accident.^[53] Three of these staff members, including the Air Traffic Manager, had worked at the facility when it was operated by the U.S. Navy.

The Guam Air Traffic Manager said that the FAA evaluated the tower facility at Guam in October 1995 to determine whether a new tower should be constructed or the existing facility should be upgraded. The FAA also evaluated the Guam tower in September 1996, and the Air Traffic Manager learned that the facility would be upgraded with digital bright radar indicator tower equipment (D-BRITE)^[54] displays.

In February 1997, two D-BRITE systems were delivered to the Agana tower, and the radar displays were installed by the FAA in July 1997. The tower controller on duty at the time of the accident stated that the D-BRITE radar display was operational but had not been certified for use. (At the time of the accident, the associated control panels for configuring the Guam tower D-BRITE video maps and settings were located at the Andersen AFB tower. According to the FAA, the equipment at the Agana tower was not certified or commissioned for use because of missing hardware and computer software.) The tower controller stated that the display showed secondary radar targets but that the radar setting selected by the Andersen AFB controllers determined whether Mode C targets would be displayed. He said that the controllers at Guam were not able to determine an airplane's position on the video map because it did not depict any final approach courses or runway orientations for the airport.

By December 1997, the two D-BRITE systems had been tested, and the Agana tower controllers received training on the systems' operation. The D-BRITE systems were certified and commissioned for use on April 11, 1998. The video map has been modified to depict the airport with extended centerlines for both runways 6L and 6R, and the system is controlled at the Guam tower.

The Agana tower controller on duty at the time of the accident told Safety Board investigators that he arrived for duty about 2215 on August 5, 1997. After that time, he and the controller on duty performed a position relief briefing, which covered airport conditions, navigation aid conditions, traffic clearances that had been issued, and the facility equipment status. After midnight, the controller performed daily administrative duties. The controller said that he was working at the local control position, which was located in the center of the tower cab facing the runway. The controller also stated that he was aware of the NOTAM regarding the out-of-service glideslope.

The tower controller said that, when Korean Air flight 801 made initial radio contact (about 0140:55), it was the only airplane that he was controlling. The tower controller said that, when flight 801 did not visually appear within 3 to 4 minutes after the airplane was cleared to land (about 0141:01), he commenced a communications search for the aircraft.^[55] The controller attempted to contact flight 801 about 0145:13 and 0150:06. Between about 0150:00 and 0151:00, the tower controller queried the CERAP controller, the ramp controller, and an Andersen AFB controller about flight 801.

1.10.2 Instrument Landing System Ground-Based Equipment

FAA Form 6030-1, "Air Traffic Control Facility Maintenance Log," for July 7, 1997, showed that the Agana tower had been notified by an FAA maintenance technician that the glideslope portion of the ILS would be out of service starting that day for extensive reconstruction. The reconstruction work included the replacement of the glideslope's equipment shelter and all cabling and the upgrade of the power systems and grounding. A NOTAM issued by the FAA on July 7, 1997, indicated that the glideslope would remain out of service until September 12, 1997. The complete ILS system was flight checked, certified, and returned to service on August 31, 1997. The Safety Board's review of the facility maintenance log revealed no entries of pilot reports regarding the ILS or related navigation systems from July 7 to August 6, 1997.

The accident airplane's CVR recorded conversation among the flight crew regarding the operational status of the ILS glideslope as they approached the airport. For example, as previously stated in section 1.1, about 0139:55, the flight engineer asked, "is the glideslope working? glideslope? yeh?" About 0139:56, the captain answered, "yes, yes, it's working." About 0140:00, the first officer responded, "not useable." About 0141:46, the captain asked, "isn't glideslope working?"

In a postaccident interview, the captain of a Continental Air Micronesia 727-200 stated that, about 1530 on August 5, 1997, he was conducting an in-flight functional test of a newly installed global positioning system (GPS)^[56] when the airplane's instrumentation showed an indication of the ILS glideslope,^[57] even though the glideslope was out of service. Specifically, the captain stated that he was on approach to runway 6L at Guam International Airport and was centered on the localizer when he noticed that the glideslope was also centered and that no warning flags were associated with the ILS. In addition, the captain said that the glideslope always indicated "center" with no warnings even when the airplane was above the normal glidepath. The first officer confirmed the captain's observations. However, the flight crew did not indicate any anomalous glideslope indication to ATC personnel or submit any maintenance writeups containing such information.

The Continental Micronesia captain told Safety Board investigators that he originally assumed that the anomalous glideslope indication he experienced was caused by an airplane anomaly. The captain further stated that he thought the anomaly might have been a result of the GPS wiring installation. The captain did not report the glideslope anomaly to his chief pilot until 2 days after the Korean Air accident. The first officer stated that he and the captain "never thought twice" about the glideslope indications because they knew the glideslope was inoperative.

According to the maintenance records for the Continental Air Micronesia airplane, the first officer's ADI and HSI were removed and replaced on August 5, 1997, after the functional test flight. In addition, the records showed repeated squawks for the first officer's ADI and HSI between August 8 and 25, 1997.

1.10.3 Instrument Approach Procedures at Guam International Airport

Instrument approaches available for runway 6L at the time of the accident were the ILS (localizer only, glideslope out of service), the VOR/DME, and the VOR.

1.10.3.1 The Nonprecision Runway 6L Instrument Landing System Localizer-only (Glideslope Out) Procedure

The execution of the Guam ILS runway 6L localizer-only (glideslope out) approach requires the use of the NIMITZ VOR as a step-down fix^[58] between the final approach fix (FAF) and the runway and DME to identify the step-down points.^[59] The DME is not colocated or frequency paired with the localizer transmitter (which is physically located at the airport); rather, it is colocated and frequency paired with the NIMITZ VOR. The nonprecision localizer-only approach requires the use of the localizer to obtain lateral guidance to the runway, the DME to identify the step-down points, and the VOR to identify the final step-down fix to the MDA. According to Jeppesen Sanderson's August 2, 1996, 11-1 ILS Runway 6L approach plate, the airplane should cross the FLAKE initial approach fix (IAF)--located at 7 DME from the VOR--at or above 2,600 feet msl.

The nonprecision approach procedure prohibits descent below 2,000 feet msl (1,744 feet above airport elevation) before reaching the outer marker identified as GUQQY, which is the FAF and is located 1.6 DME from the VOR. Upon crossing the FAF, the procedure prohibits descent below 1,440 feet msl (1,184 feet above airport elevation) until passing the VOR. The procedure calls for a descent to 560 feet msl (the MDA, 304 feet above airport elevation), and the pilot is required to count up from less than 1 DME, as the airplane passes over the VOR, to 2.8 DME, the published missed approach point (MAP) and location of the middle marker. If a missed approach is not required, the airplane can continue its descent to the runway 6L threshold, located 3.3 DME from the VOR.

According to the FAA, the DME and localizer at Guam are now frequency paired and colocated. In addition, the August 27, 1999, Jeppesen instrument chart for the ILS runway 6L approach (which became effective on September 9, 1999) states "DME or RADAR required" and includes "ILS DME" in the frequency box.

1.10.3.2 Instrument Approach Charts for Guam International Airport

During postaccident examination of the cockpit area (which had separated from the main wreckage, as discussed in section 1.12), investigators found a clear plastic sleeve, measuring approximately 8 ½ by 11 inches, that contained the following Jeppesen approach charts for Guam International Airport, all of which were dated January 19, 1996: 11-1, ILS Runway 6L; 13-1, VOR Runway 6L; 13-2, VOR DME Runway 6L; 16-1, NDB Runway 6L; and 16-2, NDB DME Runway 24R.^[60]

Charts 11-1 and 13-2 were found side by side and were visible through one face of the plastic sleeve. Chart 16-1 and the blank side of an approach plate were visible through the opposite face of the plastic sleeve. Chart 11-1, which is shown in figure 7, had the following items highlighted with a green fluorescent tint: ^[61]

Plan view

ILS facilities box: 063° (inbound magnetic course), 110.3 (ILS frequency), IGUM (identifier), and FLAKE (IAF).

VOR facilities box: 115.3 (NIMITZ VOR frequency) and UNZ (identifier).

Profile view

2500' (msl altitude crossing FLAKE).

1900' (msl altitude crossing the outer marker).

256' (touchdown zone elevation-runway 6L).

The instrument approach charts for Guam International Airport in effect at the time of the accident were issued on August 2, 1996 (with an effective date of August 15, 1996). Changes incorporated in the August 2, 1996, 11-1, ILS runway 6L approach chart (shown in figure 1) included the location names, crossing altitudes, and the missed approach procedure. Table 2 details the specific differences between the January and August 1996 instrument approach charts.

1.11 Flight Recorders

1.11.1 Flight Data Recorder The accident airplane was equipped with a Sundstrand Data Corporation model 573A FDR, serial number 2663, which was configured to record 51 parameters. The FDR recorded information digitally on four tracks using ?-inch-wide magnetic tape that had a recording duration of 25 hours before the oldest data were overwritten. Even though the FDR case was damaged by impact forces, data could be retrieved and analyzed. Examination of the data indicated that the FDR had operated normally, except for a loss of synchronization about 3 seconds before the transition to 25-hour-old data. About 3 hours 48 minutes of data were transcribed for the entire accident flight (takeoff to impact).

After an initial readout of the FDR, Korean Air provided the Safety Board with documentation that indicated that 11 additional sensors had been retrofitted after the airline took delivery of the airplane. These retrofitted sensors--exhaust gas temperature and oil quantities for the airplane's four engines, static air pressure, and the left No. 4 and right No. 12 spoiler positions--were not reflected in the FDR documentation provided by the manufacturer or the airline at the time of the initial FDR readout. Documentation for the additional sensors provided by Korean Air did not include the equations necessary to

A non-free image has been removed from this page.

Figure 7. The January 19, 1996, 11-1 ILS runway 6L instrument approach chart.
Reproduced with the permission of Jeppesen Sanderson, Inc. NOT TO BE USED FOR NAVIGATION.

Table 2. Information differences between the January 19 and August 2, 1996, Guam ILS runway 6L approach charts.

Chart dated January 19, 1996	Chart dated August 2, 1996
No note regarding DME requirement.	Note on chart stating DME REQUIRED. DME from UNZ VOR.
MILITARY (in ammendment block)	AMEND 0 (in amendment block).
HAMAL (IAF) is 8 DME on R-343.	HAMAL (IAF) is 7 DME on R-343.
ZEEKE (IAF) defined as 7 DME on R-169.	ZEEKE defined as 7 DME on R-169.
FLAKE (IAF) defined as 7 DME on R-242.	FLAKE(IAF) is defined as 7 DME from UNZ on the localizer.
FLAKE (IAF) crossing altitude is 2,500 feet.	7 DME fix (IAF) on the localizer; crossing altitude is 2,600 feet.
Outer marker fix designated OM.	Outer marker fix designated GUQQY.
GUQQY crossing altitude is 2,000 feet.	Outer marker crossing altitude is 1,900 feet.
VOR crossing altitude is 1,300 feet.	VOR crossing altitude is 1,440 feet.
Missed approach point designated 2.8 DME at the middle marker.	Missed approach point depicted in large, bold font: D2.8 UNZ VOR, MM'
Touchdown zone elevation for runway 6L.	Touchdown zone elevation for both runways 6R and 6L.
Sidestep minimums included.	Sidestep minimums deleted.
Missed approach procedure: Climb to '2500' outbound on UNZ VOR R-062, turn RIGHT direct FLAKE D7.0.	Missed approach procedure: Climb to 2600, then turn RIGHT via UNZ VOR R-242 to FLAKE D7.0 UNZ VOR and hold SOUTHWEST, RIGHT turn, 062° inbound.
Holding pattern at FLAKE depicted.	No holding pattern at the IAF or FLAKE depicted.
No obstruction symbol depicted at the VOR.	724-foot obstruction symbol depicted at the VOR.
803-foot elevation shown for UNZ VOR.	No elevation shown for UNZ VOR.
1,154-foot elevation at outer marker.	1,190-foot obstruction shown at GUQQY.
1.6 DME at outer marker depicted on plan view.	1.6 DME UNZ VOR at GUQQY depicted on plan view.
No note for FLAKE.	Note added: (FLAKE) for missed approach only.

convert the recorded information into engineering units.^[62] The Safety Board applied equations used in previous readouts of FDRs from similar 747s, but the validity of the conversion equations could not be verified.

1.11.2 Cockpit Voice Recorder

The accident airplane was equipped with Fairchild model A-100A CVR, serial number 61216. The CVR case revealed no evidence of structural damage, and the interior of the recorder and the tape showed no evidence of interior heat or impact damage. The recording consisted of four channels of "good quality" audio information,^[63] which included the captain, first officer, and flight engineer microphones; audio panels; and the cockpit area microphone. The fourth channel also recorded the interphone and the public address system.

The audio portion began about 0111:42 and continued uninterrupted until 0142:32.53. The recording ended shortly after the airplane crashed and the power to the CVR was lost. The CVR group, consisting of representatives from the parties to the investigation and the KCAB, collectively transcribed the 31-minute 1-second tape in its entirety. A bilingual (English and Korean) transcript was produced of the entire recording (see appendix B).

1.12 Wreckage and Impact Information

1.12.1 General Wreckage Description

Examination of the ground scars and the debris pattern revealed that the accident airplane impacted high terrain with the left outboard engine, main landing gear, and left wing at an elevation of about 660 feet msl and on a magnetic heading of approximately 063°.

The Safety Board performed a complete survey of the accident site and airplane structure. The main wreckage site area was in a gully covered with dense vegetation, located approximately 2,000 feet southwest of the NIMITZ VOR. The wreckage distribution area was about 2,100 feet long and 400 feet wide and included airplane debris, tree strikes, and ground impact marks. All major structural components of the airplane and control surfaces that were not consumed by the postimpact fire were identified along the wreckage path. The terrain along the wreckage path was hilly and ranged from about 673 feet msl at the first tree strikes to about 582 feet msl at the main wreckage area.

The initial point of impact was evidenced by several cut treetops that extended along the wreckage path. Several ground impact marks, consistent with the main landing gear, were found in the vicinity of the broken oil pipeline, located about 400 feet from the point of initial impact. A ground scar, about 89 feet long, 6 feet wide, and 2 feet deep, was found about 415 feet from the point of initial impact, and several pieces of the No. 1 engine cowl were found embedded in this area, along with parts of the left wing leading and trailing edge flap structure.

Numerous parts of the left main landing gear, including two wheels and tires, were found embedded in a small berm about 1,430 feet from the initial impact point. Most of the fuselage structure was located in the main wreckage area and was found separated into five major sections: the empennage, the aft fuselage, the center fuselage, the forward fuselage, and the cockpit.

Figures 8a and 8b are photographs of the wreckage from Korean Air flight 801. Figure 8a shows the airplane wreckage in relation to runway 6L, the NIMITZ VOR, and Apra Harbor.^[64] Figure 8b provides a closer view of the wreckage and the VOR.

Figure 8a. Wreckage from Korean Air flight 801 in relation to Guam International Airport runway 6L (upper middle), the NIMITZ VOR (upper right), and Apra Harbor (upper left).

Figure 8b. Closer view of the wreckage from Korean Air flight 801 and the NIMITZ VOR.

1.12.2 Fuselage and Empennage

The cockpit section was located down an embankment beyond the large portion of the forward fuselage. The airplane's VHF [very high frequency] navigational radio control panels were recovered from the wreckage. To determine which radio frequencies were selected on both the captain's and the first officer's control panels in the cockpit, an examination was conducted on October 2, 1997, under the Safety Board's supervision, at Pacific Aero Tech, an FAA-approved repair station for the control panel, in Kent, Washington. The captain's frequency selector was found tuned to 110.30 megahertz (MHz), which was the Guam localizer frequency. The captain's control panel had been damaged by impact forces, and the frequency depicted was locked into a position that could not be changed by turning the frequency selector knob. The first officer's control panel selector knob could be easily rotated, and the frequency selector was found tuned to 116.60 MHz, which did not correspond to any voice or navigation frequencies at Guam.

The cockpit section was found separated about station^[65] 400. Most of the aft nose wheel well structure (nose gear attachment point) was relatively intact with the trunnion support fittings, drag brace fittings, and transverse beam still attached. Examination of the nose landing gear and the wing- and body-mounted landing gear revealed that they were in the extended position at the time of impact. This section of fuselage structure revealed no evidence of fire damage.

The forward fuselage section approximately from stations 400 to 1120 was located on the upslope of a hill beyond the center fuselage section. The fuselage structure was split above the main deck floor on the right side, and most of the internal structure (frames, stringers, and fractured floor beams) remained attached. The structure exhibited extensive fire damage, including burn-through of the crown area (upper forward fuselage), sidewalls, and floor.

Examination of doors 1L, 1R, 2L, and 2R could not be performed in detail because the airframe structure around these doors was heavily burned, and only portions of the doors were located in the main wreckage site. The door identified as 3L was found closed and locked. Door 3R was found separated from the fuselage, with more than one-half of the door frame area missing because of fuselage separation in this area. According to Korean Air records, the 3L and 3R doors were deactivated before the company took delivery of the airplane. The doors identified as 4L and 4R were found detached from their respective mounted positions, and approximately one-third of the 4R door frame was missing. Door 5L was found closed and locked. Door 5R was found in the open position; however, the door handle was not in the full open position. The upper deck doors were not located; these doors were mounted in an area of the fuselage that sustained extensive fire damage.

The center portion of the fuselage structure, extending from stations 1120 (left side) to 1240 (right ride) and aft to station 1780, was found attached across the crown area and to the right wing by the landing gear beam. The landing gear beam at station 1350 was attached to the fuselage section. The entire center section was found rotated about 180° to the debris path, with the forward end of the section facing the aft body and empennage. The interior was extensively damaged by fire throughout the section. The exterior fuselage skin bore fire damage primarily adjacent to the break, and the right-side fuselage skin was heavily burned between doors 3R and 4R.

The exterior fuselage surface was lightly sooted on the left side of the center section, and the exterior of the right side bore evidence of light soot and areas of fire damage around the periphery of door 5R. The interior was damaged by fire from the main deck floor level to the belly; however, the upper portions of the internal structure were not burned significantly. The aft pressure bulkhead was intact, with the lower portion deformed. The bulkhead was not damaged by fire. The empennage was found separated from the aft fuselage in an upright position.

The empennage had sustained impact damage and some light fire damage. The left- and right-side horizontal stabilizers, their respective elevators, and the vertical fin (with the rudder attached) remained attached in their respective mounted positions.

1.12.3 Wings

The left and right wings were located on the left side of the airplane in the main wreckage area. The right wing remained attached to the fuselage center section, and the left wing was located under the fuselage and right wing.

The outboard section of the left wing was located approximately parallel to and under the right wing section. This portion of the left wing structure was approximately 80 percent intact and had sustained extensive postimpact fire damage to the upper skin and midspar (between wing stations 470 and 1200), including the midspar web and chord structure. The corresponding lower skin and stringers also exhibited considerable fire damage. Exposure to the postimpact fire resulted in various degrees of damage to the remaining wing structure, including the leading edge and trailing edge flap structure. The outboard wing tip, which comprised 10 composite aluminum and fiberglass structures, was found separated from the wing box at the surge tank end rib at wing station 1548 and was not damaged by fire.

Most of the right wing inboard and outboard trailing edge flaps and support structure were found intact and attached to the wing box, except for approximately 6 feet of the inboard fore, mid, and aft flap structure of the inboard-most section of the flap. This section had separated and was found in the debris path in the vicinity of the initial impact point. Examination of the ball screw indicated the flap extension was approximately 25°.

All of the leading edge variable camber flap and inboard Krueger flap structure was destroyed by impact forces and the postcrash fire. The trailing edge flaps and control surfaces were found relatively intact with some localized fire damage, except for the inboard flap system, No. 4 flap track, and No. 6 spoiler, which separated from the wing box during initial impact.

The No. 1 through No. 5 flight spoilers were found in place in a neutral position at the in-spar box structure. The spoilers exhibited extensive fire damage. The No. 6 ground spoiler had separated from the wing and could not be located among the wreckage. Examination of the spoiler support beam revealed evidence consistent with overload from impact forces.

The full combination of outboard flap and support structure on the left wing was found in place on the wing box with a detent extension indicative of approximately 25°. All of the inboard flap and most of the support structure had separated from the wing box and was found along the wreckage path, with numerous parts in the area of the initial impact point.

1.12.4 Engines

All four of the engines were found separated from their respective mounted positions on the airplane. The No. 1 engine was located about 970 feet from the initial impact point and about 1,300 feet from the main wreckage site. The other three engines were all located within the main wreckage site.

All of the engines sustained damage to the fan blades, with the tips and leading edges bent opposite to the direction of rotation. Further, vegetation and dirt had been ingested into the fans and low-pressure compressors of each of the engines. Examination of the rotating parts within each engine revealed evidence of rotational smearing, rubbing, and blade fractures that were consistent with the engines producing power at the time of impact. Further, none of the four engines exhibited any evidence of uncontained failures, case ruptures, or in-flight fires. All of the thrust reverser actuators that were found indicated that the thrust reversers on each of the engines were in the stowed position.

1.13 Medical and Pathological Information

Tissue and fluid samples from both pilots and the flight engineer were transported to the FAA's Civil Aeromedical Institute (CAMI) for toxicology analysis. The CAMI laboratory performed its routine analysis for major drugs of abuse and prescription and over-the-counter medications, and the results were negative. The analysis detected ethanol in the blood and tissue samples of both pilots and the flight engineer, but no ethanol was detected in the vitreous (eyeball) fluid sample taken from the captain. All specimens were noted in the laboratory report to have been received by CAMI in a "putrefied" condition.

According to the captain's medical records, he consulted a personal physician on July 27, 1997, and was diagnosed with bronchitis. The physician prescribed three medications: Copan (clenbuterol), a medication to open the upper airways; Vibramycin (doxycycline), an antibiotic; and Sentil (clobazam), a medication in the benzodiazepine class of drugs that is frequently used as a sedative.^[66] The postmortem tests conducted by CAMI on the captain's blood specimen were negative for benzodiazepines, and no CAMI testing was available for the detection of Copan or Vibramycin.

The remains of deceased airplane occupants were examined by the Disaster Mortuary of Guam to determine the cause of death. Because many of the remains were fragmentary, the total number of remains sets (300) exceeded the number of accident fatalities. Autopsy examinations and toxicological analysis determined that the airplane occupants died of blunt force trauma, thermal injuries, and carbon monoxide inhalation. Complete autopsies and toxicological evaluations were performed on the remains of the three flight crewmembers (as discussed previously.) Of the 297 non-flight crewmember sets of remains, about 145 sets could not be evaluated for soot in the airway because the condition of the remains precluded an evaluation. Of the 137 remains sets that could be evaluated, soot was found in the airway of 20 sets, no evidence of soot was found in 41 sets, and no definitive observations could be made regarding soot in the airway for 76 sets (in many of these 76 cases, however, the traumatic injuries described would have precluded survival after the impact sequence). Information was not available for the final 15 sets of remains.

1.14 Fire

A fire erupted during the impact sequence and was sustained by the fuel on board the airplane; the last report of small remaining fires was about 0800. The Safety Board's investigation revealed no evidence of an in-flight fire.

1.15 Survival Aspects

1.15.1 General

The 747-300 cabin contained a total of 385 passenger seats and was divided into three sections: first class, prestige (business) class, and economy class. The airplane was configured with four rear-facing, double-occupancy flight attendant jumpseats and six rear-facing, single-occupancy flight attendant jumpseats, all of which were equipped with a four-point restraint system. The flight attendant seats were located at each of the four emergency exit doors located on the left and right side of the cabin.

Of the 237 passengers aboard flight 801, 3 were children between 2 and 12 years old, and 3 were children 24 months or younger. Thirty-one airplane occupants were found alive by rescue workers Two passengers died en route to area hospitals. The autopsy report for one of these two passengers did not identify a single cause of death (her remains showed evidence of multiple internal injuries but no burns or soot in her airway). The autopsy report, however, identified that she was alive when medical personnel arrived at the accident scene and that she was treated aggressively as a result of serious injuries. In addition, 3 passengers died of their injuries within 30 days after the accident, bringing the official total number of accident survivors to 26.

Of the 26 survivors of the accident, 7 passengers and 1 flight attendant were seated in the first class section, 1 flight attendant was seated in the prestige class section, 7 passengers were seated in the forward economy class section, and 9 passengers and 1 flight attendant were seated in the aft economy class section. Two of the surviving flight attendants and 13 of the surviving passengers were seated on the right side of the airplane; 6 of these 13 passengers were seated over the right wing. Figure 9 shows the 747-300 cabin configuration and the survivor seat locations.

Figure 9. Korean Air flight 801 cabin configuration and survivor seat locations.

1.15.2 Survivor Statements

Safety Board investigators and MOCT officials interviewed a surviving flight attendant and several passengers in a Guam hospital on August 9, 1997. In addition, 11 passengers responded to a Safety Board "Survivor Questionnaire" after returning to Korea. Information obtained from the interviews and questionnaire responses indicated that these survivors either had been ejected from the airplane during the impact sequence or had extricated themselves from the wreckage. Most of these survivors indicated that they were injured as a result of the impact; however, two survivors stated that they were injured by fire. Further, the survivors stated that, during their egress from the airplane, they encountered damaged seats, overhead bins that had fallen, and other unidentified obstacles.

A flight attendant who was seated in the R1 jumpseat (in the first class section) stated that she heard a loud "boom" before the airplane began shaking violently and breaking up. The flight attendant said that she was thrown from the airplane in her jumpseat during the impact. She then unfastened her restraint system, walked about 30 feet beyond the right side of the airplane, and assisted a female passenger.

Several surviving passengers stated that, after the impact, baggage from the overhead bins fell to the floor and that "intense flames and heat swept through the cabin." One survivor, who was seated in the aft economy class section (row 34), stated that her husband was engulfed by fire in the seat next to hers. Another passenger, a professional helicopter pilot, stated he felt what he thought was a "hard landing" but that the airplane then rolled and began to disintegrate. The passenger stated that he exited the burning cabin by walking through a large hole in the fuselage. He also said that a "ball of flame was going down the center of the airplane" and that passengers were screaming and calling for help.

1.15.3 Emergency Response

About 0150, the Guam Fire Department (GFD) communications center received an emergency call from a local resident, who reported seeing a fire in the hills near the airport. About 0158, after receiving notification of the accident from the CERAP controller (based on the Ryan International flight crew's observation of a "big fireball on the hillside"), the Agana tower controller alerted ramp control about the crash of Korean Air flight 801.^[67] According to airport ramp control logs, ramp control initiated the required emergency notifications at 0202, including a call at 0208 to the Naval Regional Medical Center to place its personnel on standby. According to GFD communications center logs, notification of a downed aircraft was received from the Guam ramp control at 0207. Immediately afterward, the GFD communications center dispatched Engine Company No. 7, which was located about 3 ? miles from the accident site. According to the GFD chief, the departure of Engine No. 7 was delayed because its brakes had been drained to prevent an overnight buildup of condensation in the brake lines.^[68] Thus, the brake lines had to be first recharged with air. Engine No. 7 departed the station at 0219 (12 minutes after being notified) and arrived 15 minutes later (at 0234) at the gate to the pipeline/VOR access road (which was the only vehicle ground access to the accident site).

The Federal Fire Department's Station No. 5, located on Nimitz Hill 1 mile away from the accident site, was the nearest fire station.^[69] GFD communications center logs indicated that the federal dispatch facility was notified of the accident at 0207, but the federal dispatch facility records indicated that notification was received at 0234 and that Engine No. 5 arrived at the scene at 0239.

The Chief of Staff, Commander, U.S. Naval Forces, Marianas, who was also the wife of the airport director, testified during the public hearing that she first became aware of the crash after an airport official called her husband at 0216 to report that a Korean Air 747 was missing over the Nimitz Hill area. The Chief of Staff went outside and observed a "bright orange glow" in the sky. She then notified the Navy Security Office and Command Duty Officer to activate the Navy's "first responders," search and rescue assets, and hospital mass casualty units.

The GFD incident on-scene commander (OSC) told investigators that he arrived at the accident site about 0234 and proceeded down the access road toward the wreckage. The access road to the site--a narrow (one-lane) dirt and stone road with a drainage ditch on both sides--had been blocked by a section of damaged oil pipe. The pipe, which was located next to the road and elevated about 3 feet, was removed 1 hour later by a truckmounted winch after efforts to remove it by hand were unsuccessful. According to GFD documents, Engine No. 7 became stuck in mud when the driver tried to maneuver around the oil pipe obstruction. The GFD chief stated that, once the broken pipeline had been removed and the fire truck had been towed out of the mud (about 0345), no further blockages of the access road were reported.

In a postaccident interview and at the Safety Board's public hearing, the OSC testified that he and other rescue personnel abandoned their vehicles and approached the accident site on foot. The OSC indicated that he and the rescue personnel carried flashlights, rope, and a trauma kit. The OSC stated that he heard people screaming and could see small areas of fire. The OSC said that the darkness and terrain made access to the accident site difficult.

The OSC stated, "we had to go across all types of vegetation, sword grass, all types of trees...it was very rough getting down to the crash site, especially with no light whatsoever but flashlight alone...we had to deal with all kinds of bugs down there, snakes...we tried to pull out the survivors the best way we could and from what we received in fire-fighting training." The OSC also stated that

the airplane [had been] totally engulfed [in fire] when we got there...already to the point where the fires weren't really bothering the rescuers. The rescue personnel were actually going into the plane checking passengers...who was still alive and who was not.... We had to go back up on those slippery hills without any rappelling gear whatsoever.... We were holding the victims in one arm and holding the tools in the other so we just could make it to the top.... We did this until we could clear a landing site for the choppers....

The OSC stated that a command post was established to the east (on higher terrain) of the main wreckage site, where requests for resources and personnel were relayed by radio to the GFD dispatcher. The dispatcher then relayed the information to the response activity coordination team located at Guam Civil Defense (GCD) headquarters.

The GCD director told Safety Board investigators that he arrived at the access road gate about 0235. The director stated that the GCD owned a command post vehicle but that he did not use the vehicle because it was outdated and had been out of service for several years. He stated that funds were not available to repair and equip the vehicle.^[70]

A U.S. Navy emergency medical technician (EMT) assigned to the Naval Regional Medical Center told Safety Board investigators that he received verbal notification of the accident between 0200 and 0230 from personnel at the Guam Naval Activities Station, which is located about 8 miles southwest of Nimitz Hill. The EMT reported that he arrived at the accident site on foot between 0245 and 0300. Upon arrival, the EMT observed the fuselage and interior engulfed in "bright blue flames." The EMT stated that he approached the burning wreckage to within about 150 feet and saw about 14 survivors outside the airplane with various injuries, most of which were burn related. The EMT said that many of these survivors were clustered together and that they appeared to have extricated themselves from the wreckage.

The EMT told investigators that it was difficult to maneuver around the wreckage because of darkness, intermittent rain, soft ground, tall grass, and rugged terrain. Further, the EMT stated that two triage areas had been set up: one near the front of the airplane (near the nose section), and the other between the fuselage wreckage and the access road.

A Guam Department of Public Health physician told Safety Board investigators that she was notified of the accident by GCD about 0245 and arrived at the accident site about 0315. Upon arrival, she noted that the triage and transportation activities were "functioning well" but that medical and evacuation efforts lacked coordination. Additionally, she said that, after assessing the situation, she established another triage area near the VOR, where the terrain was level.

Some of the survivors that had been treated at the triage area near the airplane were evacuated by military helicopters, whereas others had been carried to the triage area near the VOR to be treated and then transported by ambulance via the access road. The OSC stated that the first survivors were transported to hospitals between about 0300 and 0330. The EMT stated that the last survivor was found about 0430. According to hospital records, the first survivor transported by helicopter to the U.S. Naval Hospital arrived about 0334, and the last survivor arrived by helicopter about 0710. Also, hospital records indicated that the first survivor transported to Guam Memorial Hospital arrived by ambulance about 0420 and that 16 other survivors were transported by ambulance to Guam Memorial, the last of which was admitted about 0709.^[71]

1.15.3.1 Emergency Response Planning and Exercises

At the Safety Board's public hearing, the GCD director testified that, in April 1997, a joint full-scale disaster drill had been conducted on the airport with Guam airport authorities.^[72] The GCD director stated that no off-airport drills had been conducted before the accident but that an off-airport aircraft accident drill had been scheduled for September 1998.

The GCD director added that, after the accident, new radios had been purchased to allow interagency communication and coordination during emergencies. The GCD director also testified that, before the accident, GCD authorities had a memorandum of understanding (MOU) with the U.S. Air Force for emergency response but had not established an MOU with the U.S. Navy or U.S. Coast Guard. The GCD director stated that, after the accident, Guam authorities formed an emergency response committee, which included the Navy, the Coast Guard, and the Air Force, and that an MOU involving all emergency response agencies on the island had been drafted. The director stated that the MOU called for emergency response drills involving all of the agencies.

In June 1999, the GCD acting administrator stated that, instead of the MOU, a final draft of "Joint Standard Operating Procedures for Mutual Civil Emergency Support for Emergencies or Disasters Without Presidential Declaration" was circulated to the GCD office; Commander, Naval Forces Marianas; U.S. Coast Guard Marianas Section; and the U.S. Air Force 43rd Air Base Wing. The acting administrator indicated that the procedures could be implemented by the end of June 1999. The Safety Board's latest information from the GCD office (August 1999) indicated that the procedures had not been implemented.

Officials from the GCD office stated that the planned September 1998 off-airport exercise did not take place. In June 1999, the GCD acting administrator stated that planning for a major off-site exercise had started.

1.15.4 Guam Governor's Accident Response Review

The Guam government conducted a review of its response to the accident and issued a report, titled Korean Air 801 Incident Report. According to the report, the "focus of the investigation was to identify an accurate timeline of emergency response during the first hours of the incident, and to address issues/questions raised concerning the rescue efforts. Those issues/questions concerned fire suppression, command structure and activity of key members of the rescue team."

Problems discussed in the report included the lack of radio communications between key personnel, which complicated the command situation. The report stated, "...the civilian and military components were on different and incompatible radio systems...radios had to be shared in the command post so that the various agencies could communicate."

Additionally, the report cited the remoteness of the accident site and the difficulty in bringing fire trucks close enough to the site to be effective. However, the report stated that "no fire suppression was used" because it would have "interfered with rescue operations."^[73] The report also cited accounts from rescuers that indicated, "...most of the survivors were initially located away from the flames of the aircraft.... It is noted that the first rescuers arrived approximately 55 minutes after the plane had crashed.... If the fire was as intense as originally reported [immediately after impact], fatalities caused by fire and smoke inhalation would have occurred before the rescuers arrived."

1.16 Tests and Research

1.16.1 Enhanced Ground Proximity Warning System Simulation

Because of advances in computer technology and terrain mapping capabilities, GPWS manufacturers have developed improved terrain avoidance systems. In 1997, the FAA certified a new terrain awareness and warning system (TAWS), also known as enhanced GPWS. (See section 1.18.2.2 for general information about enhanced GPWS.) This system was not installed or required on the accident airplane.^[74]

An enhanced GPWS simulation was conducted after the accident to determine the additional forewarning that the flight crew of Korean Air flight 801 would have received if such a system had been installed on the airplane. The simulation revealed that the flight crew would have received an aural "CAUTION TERRAIN" warning and a yellow visual terrain depiction on the weather radar about 60 seconds before impact. In addition, enhanced GPWS would have provided the aural annunciations "TERRAIN, TERRAIN" and "PULL UP" and a red visual terrain indication on the weather radar display about 45 seconds before impact; the annunciations would have sounded continuously until completion of a successful escape or impact with terrain.

In July 1999, Korean Air announced that it would equip all of its aircraft with enhanced GPWS by the end of 2003. The KCAB subsequently confirmed Korean Air's announcement.

1.16.2 Minimum Safe Altitude Warning System Simulation

An ARTS IIA MSAW simulation was conducted after the accident at the FAA Technical Center in Atlantic City, New Jersey. The simulation indicated that, without the 54-nm-inhibited ring, a visual and aural low-altitude alert would have been generated for flight 801 on the terminal ARTS IIA display at the CERAP facility. Further, the simulation indicated that the visual and aural approach path alert would have been generated at 0141:22, as the airplane was descending through 1,700 feet msl, or about 64 seconds before the airplane crashed.

1.16.3 Korean Air Spurious Radio Signal Tests

After the accident, the KCAB and Korean Air conducted a series of independent tests on a Boeing 747 on the ground to determine if spurious radio-frequency energy could induce an abnormal ("false") glideslope indication. These tests were not intended to represent conditions at the time of the accident; rather, the tests were designed to explore ILS system sensitivity to spurious signals. According to Korean Air engineers, the tests revealed that the glideslope deviation needle could be positioned near the middle of the glideslope reference scale, and the warning flag could be retracted by introducing a "335 MHz signal (120 Hz signal modulated at 100 percent)" near the ILS receiver antenna.^[75]

The KCAB and Korean Air technical staff demonstrated their test results to the Safety Board and parties to the investigation at a January 1998 meeting. The demonstration, which was conducted using a portable 51-RV5(B) receiver and a signal generator, indicated that a single 120-Hz signal with 100-percent modulation at the Guam ILS frequency resulted in an out-of-view glideslope flag and glideslope indicator movement.

If a glideslope signal is not being generated by the transmitter (resulting in an open frequency channel/band), the airborne glideslope receiver will continue to hunt for a glideslope signal. Although the radio-frequency filters built into the receivers are designed to bias out the majority of spurious radio signals, the postaccident testing by the KCAB and Korean Air revealed that, in the absence of a valid glideslope signal, it is possible for an airborne glideslope receiver to momentarily receive a spurious signal in the frequency band of the glideslope signal. The reception of such a signal could result in the movement of the glideslope receiver needle and present a false indication to the pilot.

1.16.3.1 Guam Instrument Landing System and Potential Interference From Spurious Radio Signals

An FAA National Resource Engineer for Navigation testified at the Safety Board's public hearing about the Guam ILS system and the potential for interference from spurious radio signals. The engineer stated that "the pilot would normally be warned that a signal is not present by the presence of a flag, a warning flag, that indicates that something about the receiver system or something about the ground system is abnormal...." The engineer testified that he assumed that the accident flight crew's remarks regarding the glideslope (as recorded on the CVR) had to do with the presence or absence of flags. He concluded that "...there must have been some sort of flag activity coming into view, disappearing from view, some time during the approach" and that the comments, although they did not convey information about the duration of any flag activity, indicated that "...there must have been enough absence of the flag for the crew to occasionally decide that the system was on the air when in fact it wasn't...."

The FAA engineer also testified that, although the glideslope at Guam International Airport had been removed from its shelter, radio signals generated by some other source could have provided an intermittent signal to the glideslope receiver, which might have prevented the instrument warning flag from remaining in view. The engineer explained that potential external sources of noise and unintended signals, which are normally too weak to be heard, can be heard on an empty channel and that, during airborne flight tests of ILSs in which the localizer or the glideslope is turned off, it has been fairly common for the cockpit instrumentation to record intermittent indications of flag and needle activity. However, he expressed that this sort of activity on the instrumentation (referred to by pilots as "flag pops") is typically intermittent and of very short duration.

The engineer testified about the types of radio signals that could potentially cause a movement of the flag. He stated that the ILS transmits two tones and that the difference in the signal strength of the tones deflects the glideslope fly-up and fly-down needle. The engineer indicated that the receiver has some circuits that look for these two tones and that the fly-up/fly-down needle indicates the difference in strength of those two tones. He added that "...the difference will be zero, and the needle will be centered when the two tones are equal...."

Further, the FAA engineer stated that the flag circuit, the other indication that a pilot sees, is driven by a signal that is the sum of the two circuits or the two signals. He indicated that "as long as the 90 and 150 [Hz] signals are both present at sufficient strength, the flag will remain out of view." The engineer also stated that, if there is no ground station transmitting and no intended ground station but some other signal, then those portions of the signal that contain 90- and 150-Hz tones^[76] would still get through those filters and could cause the needles to deflect. The engineer added that, depending on the shape of the filters' response (which varies according to receiver model and manufacturer), the circuits would experience varying amounts of intermittent deflections.

1.17 Organizational and Management Information

Korean Air evolved from Korean National Airlines, a government-owned carrier established in 1948 to provide domestic air service from Seoul to Pusan. The airline was privatized in 1969 and renamed Korean Airlines. The name was again changed to Korean Air Company, Ltd., d.b.a. Korean Air, in the 1980s.

Korean Air, based at Seoul's Kimpo International Airport, operates domestic routes to 16 airports and international routes to 54 airports, including those in North America, Europe, the Middle East, Southeast Asia, China, Australia, and Japan.

At the time of the flight 801 accident, Korean Air had a fleet of 116 airplanes: 2 Boeing 747-SPs, 15 Boeing 747-200s, 3 Boeing 747-300s, 26 Boeing 747-400s, 2 Boeing 777s, 5 McDonnell Douglas MD-11s, 14 McDonnell Douglas MD-82s, 10 Airbus A-300s, 2 Airbus A-330s, 25 Airbus A-300-600s, and 12 Fokker F.100s. Korean Air stated that its fleet was expected to grow to approximately 175 aircraft by 2005. Korean Air employed approximately 1,600 flight crewmembers at the time of the flight 801 accident. In an interview with Safety Board investigators, Korean Air management personnel stated that pilot recruitment at the company had historically been from the Korean military. However, as the airline grew, the supply of available Korean military pilots could not keep pace with the rapidly increasing demand for pilots at the company. Because of this shortage, Korean Air recruited foreign nationals to supplement its pilot force. At the time of the accident, 167 foreign national pilots were employed by Korean Air. (Most of these foreign pilots were from the United States and Canada and were hired through several crew leasing companies; the pilots' employment was subject to the terms of a renewable contract.) Of the 128 captains assigned to 747-200, -300, and -SP airplanes at the time of the accident, 69 were foreign national pilots. Also, partly as a result of the pilot shortage, Korean Air began what it referred to as an "ab-initio" (that is, from the beginning) program in 1989 that was designed to select and train candidates from zero flight time. According to a Korean Air representative, ab-initiotrained pilots were initially assigned to the smaller airplanes used to fly domestic routes. As the pilots gained experience, they were upgraded to the larger airplanes used primarily to fly international routes. At the time of the accident, 389 pilots had been trained under the ab-initio program, and Korean Air estimated that the first group of ab-initio pilots would be evaluated for possible upgrade to captain during 1998. In September 1999, a KCAB official stated that the first ab-initio-trained pilots were being upgraded to captain.

The Korean Air Deputy Director of Flight Operations testified at the Safety Board's public hearing that the Korean economy had been in a recession and that, although 1995 was "a good year," 1996 and 1997 were "in the red." This official also testified that, despite economic pressures, additional funding had been allocated by the company for safety programs. The Deputy Director of Flight Operations, in his closing remarks at the public hearing, stated:

Looking back upon this accident we feel that most of our management up to now has been [ ] perhaps too short-term, short-[sighted], and superficial in its nature. ...from this point on for the purpose of ascertaining safe flight operations we plan to make long-term plans and spare no resources in [attaining] this final objective of flight safety. Accordingly, we will adjust our management systems and invest all the more heavily into training and program development.^[77]

In a March 26, 1998, letter, however, Korean Air requested that the Safety Board remove the Deputy Director of Flight Operations' statement from the public hearing record. In its letter, Korean Air maintained that the deputy director's statement was "personal in nature" and "made in accordance with the Korean custom to express condolences on public occasions to those affected by an accident." The letter also said that "the statement could suggest a finding by [Korean Air] of management deficiencies having been ascertained as a result of internal review" and that "there has been no such finding or review." Further, the letter expressed Korean Air's belief that the company's management structure "is competent to perform its functions." The Safety Board did not delete the statement from the record.

According to the KCAB, Korean Air's president resigned in April 1999 as a result of government criticism. The vice president of Korean Air was subsequently promoted to president and chief executive officer.

1.17.1 Korean Air Postaccident Safety Initiatives

On October 9, 1998, the MOCT ordered Korean Air to suspend 138 flights per week on 10 of its domestic routes for 6 months. According to the MOCT, the action followed seven accidents/incidents (including the August 5 and September 30, 1998, events listed in section 1.17.5.2). The MOCT ordered the airline to reduce service on its Seoul to Tokyo route from 28 to 26 flights per week. According to a KCAB representative, "these accidents/incidents were without human casualties, but we mete out the severe punishment as a warning." The KCAB indicated that other administrative actions against Korean Air included the following:

• increased captain qualification requirements for large aircraft (including the 747),^[78]
• prohibition of initial assignment of large aircraft for first officers.
• increased simulator training for CRM and line-oriented flight training (LOFT), and
• special simulator training for adverse weather conditions.

After the MOCT took action, Korean Air announced that it planned to spend more than $100 million over the next 2 years on safety initiatives, including changes in pilot training and maintenance operations. Korean Air also stated that it planned to accomplish the following:

• install enhanced GPWS on all new aircraft and upgrade traffic alert and collision avoidance systems (TCAS) on all airplanes;
• recruit safety specialists to provide safety awareness training to all flight crewmembers;
• conduct regular aircraft-specific safety and training sessions for flight crews, including an expanded controlled flight into terrain (CFIT) awareness program in both initial and upgrade training;
• develop a "safety alert system" in which data about incidents, accidents, and irregular operations are gathered from every department and analyzed to identify trends and develop accident prevention strategies;
• revise simulator scenarios that reflect a variety of situations that may be encountered during line operations, including takeoffs and landings from different airports, TCAS avoidance maneuvers, and ground proximity escape maneuvers;
• standardize pilot callouts, improve takeoff, approach, and landing checklists, and enhance pilots' knowledge of local terrain; and
• ensure that all flight crewmembers receive CRM and LOFT classes that require "efficient and effective communication in the cockpit and cabin through simulated situations."

Korean Air also indicated that it planned to mandate a 30-day English language training course and implement a confidential pilot reporting system so that errors and concerns can be reported to the chief pilot without fear of reprisal. In addition, the airline implemented a "maintenance error decision air program" designed to detect potential maintenance anomalies caused by human error.

In May 1999, Korean Air's new president issued a safety policy statement and additional material to support the company's planned safety enhancements. Specifically, Korean Air reevaluated its operational philosophy and adopted a five-point "Immediate Action Plan," which contained safety measures that were designed to "minimize exposure to risk, eliminate known hazards, and curtail operations under circumstances where there may be reduced margins of safety."

First, the Immediate Action Plan imposed operational limits at five airports in Korea to minimize exposure to risk when the margin of safety may be reduced. For example, at three of the five airports, no operations can be conducted at night when the runways are wet or crosswinds exceed 15 knots. Second, the plan contained Korean Air's revised policies and procedures for operations under slippery runway conditions^[79] and the use of automation.^[80] Third, the plan included Korean Air's decision to outsource flight simulator training.^[81]

Fourth, the Immediate Action Plan stated that Korean Air's most important operating priority is safety. According to Korean Air, every company line captain participated in a series of seminars in April 1999 in which the captain's decision-making, authority, and responsibilities were redefined. These seminars reemphasized that the captain "serves as the first, and last, line of quality assurance for [Korean Air], and is charged with final responsibility for the safety of its flight operations." Last, the plan provided senior management's commitment to enhance decisionmaking, especially as it relates to flight safety matters. The plan stated that Korean Air created an Executive Action Council to resolve critical operational and support issues in a timely manner and a Flight Operations Action Team to identify and resolve critical flight operations issues.

According to Korean Air, new flight crew work rules will become effective in October 1999. The new rules are expected to be similar to the duty and rest standards established under 14 CFR Part 121 and the practices of leading airlines in the industry. Korean Air indicated that its goal was to eventually achieve a standard of 80 hours of flying time per month. Also, Korean Air stated that it was in the process of implementing an automated flight crew scheduling system purchased from Sabre Technologies. This new system was designed to monitor crew training and instrument and landing currency and automatically update compliance with flight and duty limitations. The system was expected to be fully implemented by the end of 1999.

In addition, Korean Air indicated that it has been revising its Flight Operations Manual, Aircraft Operating Manual for each aircraft type, Operations Data Manual, and Aircraft Restriction Manual from the manufacturer-supplied versions to reflect the company's standard operating procedures and achieve standardization. According to Korean Air, 8 of the total 21 chapters of the Flight Operations Manual were revised and distributed to all flight crewmembers on August 1, 1999, and the rest of the chapters were expected to be revised and distributed during October 1999. Korean Air also indicated that all of the company's Aircraft Operating Manuals had been revised and issued according to each aircraft manufacturer's schedule. A Korean Air representative said in September 1999 that the Boeing 747 operating manual had been revised four times since the flight 801 accident.

1.17.2 Korean Air Flight Crew Training Flight crew training is currently conducted at one of two facilities in Korea. Ground instruction is conducted at the Korean Air Flightcrew Training Center in Seoul, and simulator flight training is conducted at the Korean Air Simulator Flight Training Facility in Inchon. (Korean Air conducts its ab-initio training at the Sierra Academy of Aeronautics in Livermore, California, and then at its Cheju flight training facility.) To become qualified as a Korean Air flight instructor or evaluator, candidates must attend 1 week of ground school, 10 days of simulator observations, 10 days of practice simulator instruction, CRM and LOFT seminars, and check rides. Program managers and senior flight instructors provide supervision and ensure standardization. 1.17.2.1 Basic and Advanced Instrument Flight Course Korean Air provides basic and advanced instrument flight courses for every specific airplane training program. Pilots receive this training before their initial training on the particular airplane for which they are qualifying. Because the captain of the accident flight was initially trained on the Boeing 727, he took the 727 basic and advanced instrument flight courses; likewise, because the first officer was initially trained on the Boeing 747, he took the 747 basic and advanced instrument flight courses. (The captain received training on the 747 in transition courses, which are discussed in section 1.17.2.2.) According to Korean Air's flight training curriculum at the time of the accident, the basic instrument course consisted of eight 4-hour simulator periods and included modules in air work and instrument departures, arrivals, and approaches. The advanced instrument course, which expanded on the procedures taught during the basic course, included avionics operation, standard instrument departures, noise abatement procedures, standard terminal arrivals (STAR),^[82] and engine-out procedures. The advanced course consisted of 10 4-hour simulator periods. The countdown/count up DME/localizer procedure, such as the one depicted in the Guam ILS runway 6L localizer-only (glideslope out) approach, was not included in any of the Korean Air simulator training scenarios for either the basic or advanced instrument courses.

1.17.2.2 Boeing 747 Flight Crew Training

Korean Air's Boeing 747 flight crew training includes initial and transition training, which are presented in five units: ground school, cockpit procedures training, simulator flight training, airplane local training (as required), and route training. The captain and the flight engineer on the accident flight were trained according to the 747 transition training syllabus, and the first officer was trained according to the initial training syllabus.

At the time of the accident, the 747 initial and transition ground school training included instruction on general aircraft systems, normal procedures, abnormal and emergency procedures, weight and balance, performance, limitations, differences, Category II instrument approaches,^[83] a review period, and a test. The initial ground school training syllabus allocated 177 hours of instruction for both pilots and flight engineers and required about 28 hours of cockpit procedures training. The transition ground school syllabus allocated about 153 hours of instruction for captains and first officers with type ratings on other airplanes and about 157 hours for flight engineers with qualifications on other airplanes. Pilots and flight engineers were required to complete about 24 hours of cockpit procedures training.

Flight training for the initial and transition courses included 40 hours of simulator time (10 4-hour training periods in which each pilot performed as a PF and a PNF for 2 hours) and a 2-hour proficiency check period. At the time of the accident, the Korean Air simulator training syllabus for 747-100, -200, and -300 initial and transition training consisted of 10 profiles that described the events to be accomplished during each training period. Each profile listed the approaches to be performed, including the specific airport, runway, weather, and airplane malfunction, and information on whether the approach would be made to a landing or the reason for a missed approach or go-around. The 10 training profiles consisted of the following approach scenarios: ? ? ? ? 23 ILS approaches to runway 14 at Kimpo Airport; 5 VOR and VOR/DME approaches to runway 32 at Kimpo Airport; 2 NDB approaches, one to a runway at Cheju Airport and one to a runway at another airport; and 1 localizer (LOC) approach to runway 14 at Kimpo Airport.

After accomplishing the 10 simulator training profiles, pilots were given a proficiency check using the scenarios contained in the 11th simulator profile. Korean Air training records indicated that the 11th simulator profile consisted of four ILS approaches to runway 14 at Kimpo Airport and one VOR/DME approach to runway 32 at Kimpo.

The 747-200 Simulator Training Guide for Instructors, dated February 1997, detailed the various training scenarios used in 747-100, -200, and -300 simulator training at the time of the accident.^[84] The training guide described only one of the nonprecision approaches: the VOR/DME approach to runway 32 at Kimpo Airport. The description for this approach included the DME distance to initiate gear and flap configuration changes and specific vertical speed settings during step-down fixes on the approach procedure. Also, this nonprecision approach scenario always involved DME that was located on the airport and colocated and frequency paired with the primary approach navigational facility. Thus, all simulator approach scenarios using DME were approaches for which the pilot had to count down toward the MAP.

The simulator training curricula did not contain nonprecision approaches to other airports or with varied or diverse scenarios. For example, no approach scenarios required the pilot to count down to the DME, fly past the DME, and count up to the MAP, which was required for the runway 6L ILS localizer-only (glideslope out) approach to Guam. At the Safety Board's public hearing, Korean Air's Director of Academic Flight Training and a Korean Air check airman testified that the simulator scenarios were to be followed as published in the training curricula. They also indicated that there were no provisions or guidance that enabled instructors to vary the nonprecision approach scenarios from those published.

The Korean Air Simulator Training Guide contained specific approach scenarios to be used during proficiency checks and type rating simulator checks. These approach scenarios were the same ones taught and practiced during the initial and transition training sessions.

After the accident and subsequent discussions with the Safety Board, the KCAB asked Korean Air to modify its simulator training syllabus to include diverse approaches. The Safety Board notes that the Korean Air simulator training now incorporates a variety of approach scenarios, including approaches in which the DME is not colocated with an on-airport navigational facility and approaches involving countdown/count up DME procedures. Also, the simulator training now includes approaches that are likely to be encountered during domestic and international line operations.

1.17.2.3 Crew Resource Management Program

The Korean Air Director of Academic Flight Training stated that the company instituted a CRM training program in December 1986 as a result of the Korean Air shoot down accident in August 1983 off the coast of the Soviet Union. The director stated that the CRM sessions are not graded and that no program records are kept. Pilots are evaluated on CRM during route checks and proficiency check rides. In addition, pilots receive LOFT^[85] during simulator sessions once a year and are evaluated based on how they interact in coping with various anomalies during the simulated flight. According to Korean Air, a total of 1,614 flight crewmembers had successfully completed CRM training classes as of May 1999.

The CRM program that was in place at the time of the flight 801 accident was developed from the United Airlines CRM program and adapted with the assistance of an outside contractor. This 4-day program, which was provided to flight crews only, emphasized dilemma resolution and focused on teamwork and leadership in problemsolving at the individual, crew complement, and organizational levels. The CRM program used reading materials, films, and class exercises to help flight crewmembers recognize and improve aspects of their behavior and interaction. The Director of Academic Flight Training testified that this CRM program taught first officers and flight engineers to intervene and challenge the captain if they had safety or operational concerns. He noted that the company had encountered difficulties teaching some first officers and flight engineers to challenge the captain and intervene in safety-of-flight situations. The director also testified that this issue was no longer a problem in training and that captains were being taught to encourage a cockpit environment in which first officers and flight engineers could freely express concerns when necessary.

In May 1999, Korean Air announced it would replace the existing CRM program with a new CRM program that was developed with and adopted from Delta Air Lines. The new program will consist of four courses: a base course, a course for new captains, a recurrent course, and a recurrent joint flight operations/cabin services course.^[86] The onetime base course, called "Error Management CRM," will last 5 days: the first 3 days will be classroom instruction, the fourth day will be a jumpseat observation flight, and the fifth day will be a debriefing session. The one-time "In-Command" course for new captains will last 1 day. The 1-hour pilot recurrent course and the 3-hour recurrent joint flight operations/cabin services course will be presented each year. According to Korean Air, the courses will be taught through lectures, class exercises, reading material, and other techniques to impart practical skills for the crews. In addition, Korean Air stated that its new CRM course would add "realism" to training through an audio-visual presentation format. Korean Air indicated that it expected to implement this program by January 2000.

1.17.2.4 Postaccident Changes to Flight Training

In addition to the changes being implemented in response to the MOCT action and as part of the Immediate Action Plan and the new CRM program, Korean Air indicated that it has made other changes in the area of flight training. For example, the company's Flight Standards Branch, within the Flight Operations Department, is now primarily responsible for overall quality assurance for all flight training and checking activities. Other changes are as follows:

• Beginning in November 1998, training modules on risk and error management and recovery training for CFIT awareness, GPWS and windshear warnings, slippery runways, and crosswind and icing conditions were added to the recurrent proficiency training curriculum for all airplane types.
• In January 1999, a policy of training to proficiency in the recurrent training and checking system was implemented. Crewmembers are to be given three opportunities during recurrent training and checks to receive additional instruction and correction while training to the acceptable level of proficiency.
• Also in January 1999, the Flight Operations Department changed its system for selecting candidates for aircraft transition and upgrade to incorporate "more objective" criteria. The standards for upgrading to captain were also revised. The new standards increase the minimum requirements from 3 years and 3,000 hours to 5 years, 4,000 hours, and 350 landing cycles with the company regardless of previous military or other aviation experience.
• In April 1999, new standardized flight instruction manuals were issued.
• A new Line Check Pilot Manual was being developed to include detailed procedures and requirements so that check pilots could consistently apply and enforce company standards and policies. The new manual was expected to be completed in October 1999.
• The Flight Operations Department developed a new all-volunteer system, to replace the previous assignment system, for all line check pilots. Candidates who volunteer for these positions are to be selected based on their ability to judge deficiencies in training and impart line flying skills. Also, the training requirements for line check pilots were increased so that the check pilots could impart better decision-making and crew coordination skills to the line pilots.

1.17.3 Korean Air Preflight Procedures

The Korean Air Operations Manual that was in effect at the time of the accident (dated May 21, 1997) stated that crewmembers were to arrive at the company dispatch center at least 1 ? hours before the scheduled departure time for international flights. According to company procedures at the time, flight crewmembers were to receive their paperwork and then gather as a group to study the paperwork. This process, referred to as the "self-briefing," typically lasted about 15 minutes. The flight crewmembers then met with their assigned SOF for the "SOF briefing." Afterward, the captain met with the flight and cabin crewmembers for a "full crew briefing."

Korean Air stated that, in March 1999, it began issuing "flight-specific manual packages" to outbound crews to ensure that pilots possessed updated route information for each trip. In addition, the company said that it developed an airport information program to promote additional route and airport familiarization. Korean Air expected that this program would be completed by the end of 1999 and that it would cover all of the airports serviced by the company's aircraft.

1.17.3.1 Supervisor of Flying Program

According to Korean Air officials, the company's SOF program began in 1996. The officials described the SOFs as retired captains and instructors who were among the company's most experienced pilots and had no record of disciplinary action. The officials stated that the purpose of the SOF briefing was to ensure that pilots had reviewed all pertinent materials for the flight, including any NOTAMs. Further, the SOFs were expected to periodically check crewmembers' charts and manuals for currency as well as their airman certificates and passports, which are required documents for international flights. There is no formal checklist of items to be covered in the SOF briefing. The officials stated that the SOF briefings were designed to last 15 minutes but averaged about 10 minutes.

In a postaccident interview with Safety Board investigators, the Korean Air Deputy Director of Flight Operations said that he initiated the SOF program to correct pilot performance deficiencies that were involved in the accident/incident events (see section 1.17.5.1) and violations that the company had been experiencing.^[87] Further, the deputy director said that he was not aware of any other air carrier that had a SOF program and that he believed the number of accident/incident events and violations had dramatically declined since the initiation of this program. The SOF for Korean Air flight 801 was a retired company 747 captain. The SOF stated, in a postaccident interview, that he reviewed the flight data and asked the flight crew about the weather conditions en route to and at Guam. The SOF also stated that he and the flight crew discussed a typhoon and the possibility of en route turbulence and that he recommended maximum use of the weather radar. The SOF further stated that he and the flight crew discussed company notices but did not discuss the NOTAMs pertaining to Guam and the out-of-service glideslope associated with the runway 6L ILS approach.^[88] The SOF did not check the flight crew's charts for currency. The SOF said that his main concern was to confirm that the flight crewmembers had "looked at the [trip paperwork] items closely."

1.17.3.2 Airport Familiarization Program

Korean Air stated that, in June 1997, it established an airport familiarization program that used audio-visual presentations (purchased from Japan Airlines) to prepare pilots for operations into designated airports. Korean Air requires that an airport familiarization tape be viewed if the company or the FAA list that airport as a "special airport." Title 14 CFR Section 121.445 defines special airports as those that require a special airport qualification for pilots-in-command because of "surrounding terrain, obstructions, or complex approach or departure procedures."^[89] Guam International Airport was not classified by Korean Air or the FAA as a special airport; thus, the accident flight crew was not required to view this familiarization tape. However, Korean Air recommends that pilots view a familiarization video if they have not flown into the destination within the preceding 3 months. The airport videotapes are available to pilots 6 days a week. The audio-visual presentation for Guam gave a general description of Guam's weather and topography, including Mount Alutom, located near the outer marker, and Mount Macajna, located north of the NIMITZ VOR. The presentation advised pilots that "...when you report airport-in-sight, you will be cleared for a visual approach." Further, the presentation stated that "...you [the pilot] will be radar-vectored to ILS runway 6L.... Normally, you will be guided from over Apra Harbor to the localizer.... You will then perform a visual approach." The presentation highlighted the visual approach, identified visual cues for the approach to runways 6L and 24R, and advised pilots not to fly over a hospital located northwest of the airport.

1.17.4 Korean Air Descent and Approach Procedures 1.17.4.1 Briefing and Checklist Usage

A Korean Air instructor pilot testified at the Safety Board's public hearing that the company required the PF to conduct an approach briefing for every approach and that the briefing was to include the division of crewmember duties during the approach procedures. The instructor pilot stated that, if a pilot receives information that a navigational aid, such as a glideslope, was reported to be unreliable or unusable, Korean Air policy requires the pilot not to use that navigational aid to conduct the approach. The Korean Air 747 checklist booklet contained a landing briefing card (dated September 10, 1996), listing the following required items for a landing (or approach) briefing: ^[90]

LANDING BRIEFING

1. . WEATHER
2. . STAR

• • TOD
  • No 1 & No 2 VOR/ADF Courses
  • ALT [altitude] & SPD [speed] Restrictions
  • Arrival Routes

1. USING RUNWAY, TYPE OF APPROACH, AND TRANSITION LEVEL 4. REVIEW OF INSTRUMENT APPROACH PROCEDURES

• Minimum Safe Altitude
• Approach Frequency (ILS, VOR, ADF)
• Approach Course
• Touch Down Zone Elevation
• Missed Approach Procedure
• Holding Procedure

5. CREW ACTION AND CALL OUT

6. PARKING SPOT AND TAXI WAYS

• DOCKING GUIDANCE SYSTEM

7. OTHER ABNORMAL CONFIGURATION AND CONDITION

TIME: BRIEFING SHOULD BE COMPLETED PRIOR TO ARRIVAL OVER TOD

The Korean Air instructor pilot testified that company pilots were taught to include the following items in a nonprecision approach briefing:

• ATIS information, including the weather, expected approach procedure, and field NOTAMs;
• arrival and descent procedure to the IAF; runway, type of approach, and type of transition; transition level;
• instrument approach procedure in detail;
• airport name and chart number;
• approach plate issue and effective dates;
• minimum safe altitude; airport elevation;
• special notes;
• configuration of navigational receivers and how to tune and identify them; crew actions and callouts; *procedure to intercept approach course;
• step-down altitudes and how they were determined;
• MDA and how it was determined;
• MAP;
• parking spot and taxiways; and
• instruction to nonflying crewmembers to call out any abnormalities or deviation from procedures.

Korean Air's checklist philosophy, as described in its Boeing 747 Guidebook,^[91] states the following:

Normal procedures[^[92]] for each phase of flight are performed by recall, and the normal checklist is used to ascertain that all the safety items have been accomplished. Each response to the checklist challenge should be preceded by the verification of the present configurations, and the crewmembers should check for conformation. If any disagreements have been found between present configuration and checklist response, corrective actions should be taken first before any further checklist challenge.

The Korean Air Boeing 747 Guidebook states that the "descent checklist" is to be performed while the airplane is descending through 20,000 feet to approximately 18,000 feet (or 1,000 feet above transition level in North America). The guidebook also states that the "approach checklist" is to be performed after a speed reduction to 250 knots and while the airplane is descending through 10,000 feet with its inboard landing lights on and that the "landing checklist" is to be performed when the airplane has been configured for landing.

1.17.4.2 Flight Crew Actions and Callouts During Nonprecision Approaches

A Korean Air simulator instructor testified that the company trained its pilots to utilize the step-down rather than the "constant angle of descent"^[93] technique when executing nonprecision approaches. However, the instructor stated that captains were permitted to use the constant angle of descent approach technique under visual conditions provided that they did not descend below the published intermediate step-down altitudes. The Korean Air simulator instructor also stated that, at the time of the accident, pilots were trained to fly a nonprecision approach with the autopilot either engaged or disengaged. With the autopilot engaged, the PF was instructed to program the autopilot/FD controls, including vertical speed and the altitude select, unless the PF specifically directed the PNF to perform that function. In addition, the PF was instructed to initiate all heading, course, and altitude changes, including the selection of the step-down altitudes, while executing the approach profile. Further, the PNF was instructed to monitor the approach and challenge the PF when necessary.

Korean Air did not provide the Safety Board with any documentation from its operations or training manuals on specific PF and PNF roles and duties taught during ground and simulator training. For approach procedures, the only specified duties for the PNF, as described in Korean Air's Boeing 747 Guidebook and 747 Aircraft Operating Manual (page 04.27.01, dated January 30, 1980), were as follows:

• Position flap lever as directed.
• Prior to crossing the outer marker cross-check all flight and navigation instruments, observe all warning flags retracted and all radios tuned to correct frequencies.
• Position landing gear lever down on command.
• Use windshield wipers and rain repellant as required.
• Check AUTO SPOILERS and AUTO BRAKE DISARM lights.

The Korean Air 747 Aircraft Operating Manual (dated October 1, 1984) described the following conditions and locations and the standard callouts for the PNF (with the flight engineer monitoring) during IFR conditions:

• First positive INWARD motion of localizer bar: "Localizer."
• First positive motion of glide slope bar: "Glide slope."
• Final fix inbound (altimeter, instrument, and flag crosscheck): "Outer Marker/VOR/NDB/etc., Time, ____ Feet, altimeters and instruments crosschecked."
• 1000 and 500 ft above field elevation (altimeter, instrument, and flag crosscheck): "1000/500, altimeters and instruments crosschecked."
• After 500 ft above field elevation: (Call out significant deviations from programmed airspeed, descent, and instrument indications.)
• 100 ft above DH [decision height]/100 ft above MDA: "100 above."
• Reaching DH or MAP: "Minimums, approach/strobe/centerline lights-- runway (or no runway).

Korean Air indicated that Standardization Circular 90-07, "747 Standard Callouts" (dated April 1996), described actions and callouts to be made during a nonprecision approach. The Standardization Circular Manual, which was issued to all pilots, contained general and aircraft-specific information. However, the callouts were not included in Korean Air's Boeing 747 Aircraft Operating Manual, company Operations Manual, or 747 Flight Crew Training Manual. Korean Air indicated in July 1999 that its pilots were trained to use the standard callouts during initial simulator training and were checked for the use of these callouts during simulator and line checks. Korean Air also stated that its pilots "always take this document in flight" and that the document is "readily available to pilots." The callouts presented in the standardization circular for the PF, PNF, and flight engineer (F/E) are as follows:^[94]

At 20,000 ~18,000 Feet msl:
PF	Initiates Descent Checklist
PNF	N/A
F/E	Executes Descent Checklist
Approaching Transition Level:
PF	Transition Altimeter Reset
PNF	Transition Altimeter Reset
F/E	Transition Altimeter Reset
At 10,000 Feet msl:
PF	Initiates Approach Checklist
PNF	Calls "One Zero Thousand"
F/E	Executes Approach Checklist
1,000 Feet Above Initial Approach Altitude:
PNF	Calls "One Thousand to Initial"
PF	Responds to PNF "Roger"
F/E	N/A
On Intercepting Heading (Check VOR/NDB Freq. and Inbound Course):
PF	Select VOR/LOC Mode
PNF	Confirms "Select VOR/LOC Mode'
F/E	Monitor Auto Mode and Monitor Instruments
First Positive Inward Motion of Localizer Bar:
PNF	"VOR Approach;**" "CDI [course deviation indicator] Alive;"
PF	"CDI Capture;" (NDB Approach**)
F/E	Responds "Roger" Monitor Auto Mode, Monitor Instruments

**	PF	Orders flap extension on approach then calls "Command Bug Set"
	PNF	Responds "Command Bug Reset"
	PF	Sets Auto Brake and Places Speed Brake Lever

After CDI LOC Bar Moving:
PF	Requests "Set Inbound Heading"
BNF	Responds "Setting Inbound Heading"
F/E	N/A
Leaving Initial Approach Fix (IAF):
PNF	States "Leaving IAF (name), Time Check, Altitude"
PF	Responds "Roger"
F/E	Monitors Altimeter and Altitude Cross Check, Monitor Instruments
Landing Gear Down and Landing Checklist:
PF	Calls Gear Down, Flaps Down (incrementally), Requests "Landing Checklist"
PNF	Responds to confirm gear position and flap postion
F/E	Monitors Altitude, Attitude and Airspeed.
Over Final Approach Fix (Call "Time" and Push Clock Button):
PF	States "Outer Marker/Final Approach Fix"
PNF	Responds "Outer Marker/Final Approach Fix, Time, Altimeter, and Instrument Cross-Check"
F/E	Monitors Altitude, Attitude and Airspeed
1,000 Feet Above Field Elevation (Altimeter, Instrument & Flag Check):
PNF	States "One Thousand"
PF	Responds "No Flag, Gear and Flaps"
F/E	Responds "No Flag, Gear and Flaps" and Monitors Instruments
On Final Approach--Deviation Call: The PNF will call any of the following deviations--Bank 15 degrees at or above, DME & Altitude, CDI Exceeds 1/3 dot, Indicated Airspeed exceeds 10 knots, Below Minimum Altitude, Too High or Low on VASI or PAPI [precision approach path indicator]
100 Feet Above MDA:
PF	Looks for Visual Cues
PNF	States "One Hundred Above"
F/E	Monitors Instruments
At MDA:
PNF	States "Minimums"
PF	Responds "Roger"
F/E	Monitors Instruments

1.17.4.3 Terrain Avoidance Recovery Maneuvers

At the time of the accident, one manual issued to Korean Air flight crewmembers--the company's 747 Aircraft Operating Manual--contained written guidance on when to execute a recovery maneuver to avoid terrain. Under the section entitled "PULL UP/TERRAIN AVOIDANCE," the manual stated:^[95]

The published RECOVERY MANEUVER procedure is immediately accomplished by recall whenever the threat of ground contact exists. Either of the following conditions is regarded as presenting a potential for ground contact:

• Activation of the "PULL UP" warning.
• Inadvertent windshear encounter or other situations resulting in unacceptable flight path deviations.

Korean Air's 747 Aircraft Operating Manual (page 14.20.02, dated November 2, 1992), required the following procedures for the recovery maneuver:

Aggressively position the thrust levers forward to ensure maximum thrust is attained, disengage autopilot and autothrottle (as installed), and rotate smoothly at a normal rate toward an initial pitch attitude of 15 degrees.

Do not use flight director commands.

Pitch attitudes in excess of 15 degrees may be required to silence the "PULL UP" warning and/or avoid terrain.

Note: In all cases, the pitch attitude that results in intermittent stick shaker or initial buffet is the upper pitch attitude limit (this may be less than 15 degrees in a severe windshear encounter).

Large thrust increases may result in a nose-up pitching tendency requiring forward column pressure and trim.

Monitor vertical speed and altitude. Do not attempt to change flap or gear position or regain lost airspeed until ground contact is no longer a factor.

{{x-lar1.17.5 Korean Air Accident and Incident History

The Safety Board used data provided by Airclaims Limited^[96] to compare Korean Air's safety record with the records of five major U.S.-based airlines and five major Asian-based airlines. The total hull loss records for all of these airlines were calculated for a 10-year period ending December 31, 1998, using two measures of activity or exposure to risk: aircraft flight hours and departures. Airclaims Limited defines a total loss as an aircraft that has been destroyed or for which the estimated repair costs rendered the aircraft a total loss under the terms of the insurance contract. (Airclaims Limited notes that some airplanes that became total losses were repaired and returned to service.) Any total loss that resulted from a deliberate violent act was eliminated from the Board's comparison. The results of the comparison are shown in table 3.

Table 3. Loss totals and rates for the 10-year period ending December 31, 1998, by losses per 1 million departures.

Operator	Losses[table3 1]	Aircraft[table3 2]		Aircraft[table3 3]
		Hours	Depatures	Hours	Depature
All Nippon Airways	0	2,751	2,069	0.00	0.00
Japan Airlines	0	3,535	1,396	0.00	0.00
Delta Air Lines	1	15,988	9,614	0.06	0.10
Northwest Airlines	1	10,570	5,598	0.09	0.18
United Airlines	2	16,075	7,372	0.12	0.27
American Airlines	3	18,823	8,607	0.16	0.35
US Airways	6	11,700	8,988	0.51	0.67
Singapore Airlines	1	2,351	598	0.43	1.67
Asiana Airlines	1	803	576	1.25	1.74
Korean Air	6	2,522	1,252	2.38	4.79
China Airlines	5	1,090	426	4.59	11.74

1. Loss totals include all local hull losses, excluding acts of violence.
2. Aircraft hours and departures are expressed in thousands.
3. Loss rates are expressed as accidents per 1 million aircraft hours and 1 million departures.

As table 3 indicates, eight of the operators had fewer than one hull loss per 1 million flight hours (All Nippon Airways, Singapore Airlines, Japan Airlines, Northwest Airlines, United Airlines, US Airways, Delta Air Lines, and American Airlines). Asiana Airlines had 1.25 hull losses per 1 million flight hours, Korean Air had 2.38, and China Airlines had 4.59.

Seven operators in the comparison group had fewer that one hull loss per 1 million departures (All Nippon Airways, Japan Airlines, Northwest Airlines, United Airlines, US Airways, Delta Air Lines, and American Airlines). Two operators had between one and two hull losses per 1 million departures (Singapore Airlines and Asiana Airlines). Korean Air Lines had 4.79 hull losses per 1 million departures, and China Airlines had 11.74. 1.17.5.1 1983 to 1997 Accident History

Between 1983 and the time of the flight 801 accident, Korean Air experienced several accidents that were attributed primarily to pilot performance.^[97] Some of these accidents resulted in substantive management, operational, and policy changes initiated by the company to correct deficiencies identified by the accident investigations. The following is a brief description of some of these pilot performance accidents:

• On August 31, 1983, Korean Air flight 007, a 747-200B, crashed in the Sea of Japan off Sakhalin Island, Soviet Union, killing 269 people. Although the airplane was intentionally shot down, the investigation^[98] revealed the flight crew likely made a navigation entry error in the autopilot, causing the airplane to depart from its assigned flightpath without the crew's detection and subsequently enter restricted airspace in the Soviet Union.^[99]

• On December 23, 1983, Korean Air flight 084, a Douglas DC-10 on a scheduled cargo flight, collided head on with SouthCentral Air flight 59, a Piper PA-31 on a scheduled commuter flight, on a runway at Anchorage, Alaska, in heavy fog. Three people received serious injuries, and three people received minor injuries. The Safety Board determined that the probable cause of the accident was the failure of the Korean Air pilot to follow accepted procedures during taxi, which caused him to become disoriented while selecting the runway; the failure of the Korean Air pilot to use the compass to confirm his position; and the decision of the Korean Air pilot to take off when he was unsure that the aircraft was positioned on the correct runway.^[100]

• On July 27, 1989, a Korean Air McDonnell Douglas DC-10-30 crashed in fog about 1.5 kilometers short of the runway at Tripoli International Airport, Libya, during the execution of a nonprecision approach (in which the ILS was out of service).^[101] Of the 199 people on board the airplane, 4 crewmembers and 68 passengers died; 6 people on the ground were also killed. The Libyan Civil Aviation Authority determined that the cause of the accident was improper flight crew coordination likely influenced by fatigue.^[102]
• On August 10, 1994, a Korean Air Airbus A300-620R landed long at a high rate of speed and overran the runway at Cheju Airport, Korea, after an apparent misunderstanding between the flight crewmembers as to whether they should continue with landing or abort and execute a go around.^[103] All of the 160 airplane occupants survived the crash. The airplane was destroyed. According to Korean Air personnel, both pilots were jailed temporarily, and neither resumed flight service with the company.^[104]

1.17.5.2 1998 and 1999 Accident and Incident History

Since the time of the Korean Air flight 801 crash, the company has experienced several accidents and incidents, some of which are detailed below.

• On August 5, 1998, Korean Air flight 8702, a Boeing 747-400, HL7496, skidded off the runway and crashed during a landing roll in heavy rain at Kimpo Airport in Seoul. None of the 16 crewmembers were injured, and 65 of the 379 passengers received minor injuries. The accident caused substantial damage to the airplane. The KCAB's investigation determined that the accident was caused by the captain's misuse of the thrust reverser during the landing roll and his confusion over crosswind conditions.^[105]

• On September 30, 1998, Korean Air flight 1603, a McDonnell Douglas MD-82, HL7236, overran a runway at Ulsan Airport, Korea, in heavy rain. None of the 6 crewmembers were injured, and 3 of the 142 passengers received minor injuries. Both engines' fan blades were damaged as a result of the event. The KCAB determined that this event was the result of "high speed over a wet runway."

• On March 15, 1999, Korean Air flight 1533, a McDonnell Douglas MD-83, HL7570, overran a runway at Pohang Airport, Korea, during a second landing attempt and crashed into an embankment. The accident occurred in stormy weather with strong winds. One of the 6 crewmembers and 15 of the 156 passengers were injured. The airplane received substantial damage as a result of the accident. The KCAB determined that the cause of the accident was the flight crew's "poor action" in bad weather (including gusts and variable winds), misuse of the brake and thrust reverser during the landing roll, and lack of decision-making for executing a go-around and stop.^[106] In addition, the KCAB believed that the flight crew received poor ground assistance.
• On April 15, 1999, Korean Air flight 6316, a McDonnell Douglas MD-11, HL7373, crashed in a residential area of Shanghai, China, about 6 minutes after takeoff.^[107]The two pilots and one mechanic on board the airplane were killed. Additionally, at least 4 people on the ground were killed, and 37 others were injured. The airplane was destroyed by impact forces. The accident is being investigated by the Civil Aviation Administration of China with participation by the Safety Board and the KCAB.

1.17.6 Oversight of Korean Air 1.17.6.1 Korean Civil Aviation Bureau

As previously stated, the KCAB, a division within the MOCT, is responsible for providing oversight of the Korean civil airlines. The Safety Board found that two KCAB operations inspectors were assigned to provide oversight of Korean Air's flight operations at the time of the accident. Neither of these inspectors were type rated in any of the airplanes operated by Korean Air. According to the KCAB, these two inspectors also had oversight duties at Asiana Airlines, another domestic air carrier.

The KCAB stated that, before the flight 801 accident, it performed an annual 7-day safety inspection, quarterly 7-day regional inspections, and random inspections an average of 40 times per year. The KCAB also said that it frequently relied on Korean Air to selfreport corrective actions taken in response to KCAB inspections.

During testimony at the Safety Board's public hearing, the Korean Air Director of Academic Flight Training stated that the KCAB approved all company aircraft operations manuals, training manuals, training programs, and flight operations procedures.^[108] The official also stated that the KCAB provided direct oversight of Korean Air and its training curricula primarily during the annual safety inspection and two to three random operations inspections each year.

Korean Air's Director of Academic Flight Training also testified that the KCAB conducted almost all type-rating proficiency checks on the company's Fokker F.100 and McDonnell Douglas MD-82 airplanes. However, the official said that type-rating proficiency checks on the other airplanes in Korean Air's fleet, including the 747-200, -300, and -SP, were conducted by company check airmen designated by the KCAB.^[109]

Korean Air's Director of Academic Flight Training could not recall any direct surveillance by the KCAB on 747 proficiency checks or training sessions. The Korean Air official indicated that, if company records indicated otherwise, he would forward such information to the Safety Board after he returned to Korea. The Board never received any such information from Korean Air.

The KCAB, however, stated that it had written records of such surveillance and that it had given these records to Korean Air. The Korean Air Director of Safety and Security stated that the KCAB provided oversight for the Korean Air simulator training syllabi during the annual safety inspection. This director further stated that, before the accident, he was not aware of any KCAB written criticisms or required changes to the Korean Air flight training program. The Korean Air Director of Academic Flight Training testified that he could not recall any KCAB written record of recommended or required corrective actions as a result of its inspections before the Guam accident. However, the KCAB stated that it has written records of recommended and required actions from its inspections before the accident.

The KCAB stated that, after the flight 801 accident, it hired five inspectors (three of whom were captains), two examiners, and two technical experts. The KCAB also stated that it hired 14 commercial pilots to provide in-house technical expertise. These pilots, however, are not directly involved in oversight activities. In addition, the KCAB inspectors now assigned to Korean Air are type rated in the Boeing 747-400, and they previously flew 747 Classics (that is, the 747-100, -200, -300, and -SP).

Further, the KCAB indicated that, after the accident, it instituted the following changes regarding its oversight of Korean Air: increased simulator training requirements for adverse weather conditions, risk avoidance, GPWS, and terrain awareness; mandated CFIT prevention concepts in recurrent ground school that are to be practiced in simulator training; diversification of training scenarios, including those airports with approach navigational aids that are not colocated with the field of landing; separate localizer and VOR approach requirements included as training items for nonprecision approaches; and a requirement to choose random profiles for check rides.

1.17.6.1.1 Accident and Incident Investigation Authority

The KCAB's Division of Aviation Safety is responsible for aviation accident and incident investigations.

Paragraph 5.4 in Annex 13 to the Convention on International Civil Aviation (Chicago Convention)^[110] specifies in part that "the accident investigation authority shall have independence in the conduct of the investigation and have unrestricted authority over its conduct." Further, on November 21, 1994, the Council of the European Union (EU) adopted a directive that specified that EU Member States would ensure, within 2 years, that aviation accident and serious incident investigations were conducted or supervised by a permanent body or entity that is functionally independent of the national aviation authorities responsible for regulation and oversight of the aviation system. According to

EU officials, all EU Member States have complied with this directive or are moving toward full compliance.

1.17.6.2 Federal Aviation Administration

Korean Air was granted authority to operate into U.S. airspace under the provisions of 14 CFR Part 129 and International Civil Aviation Organization (ICAO) Annex 6.^[111]The FAA approves operations specifications and assigns a principal operations inspector (POI) to each foreign carrier.^[112] The POI assigned to Korean Air at the time of the accident was not qualified in any of the airplanes operated by Korean Air, but no international or FAA provisions require that inspectors be qualified or current in any aircraft operated by the foreign air carrier for which they have responsibility. This POI also provided oversight to six other international air carriers. The POI said that, at the time, it was customary for the FAA to rotate inspectors of foreign air carriers so that each foreign airline was assigned a different inspector every 1 to 2 years.

The POI also said that there was no formal interaction between the KCAB and the FAA regarding oversight of Korean Air. Neither civil aviation authority (CAA) was required to formally or informally exchange reports of inspection activities or safety concerns. The KCAB, however, indicated that it and the FAA have an ongoing exchange of reports on inspection activities, violations, and certificate actions as well as safety concerns. Further, the POI assigned to Korean Air said that the FAA's oversight role for Part 129 operators was to approve operations specifications, inspect trip records and facilities, and accomplish ramp inspections of airplanes and crews when they were in the United States or its territories. The POI also stated that the FAA did not inspect, approve, or provide oversight for a foreign airline's training or operations manuals. The Safety Board has not identified any requirement under the Convention on International Civil Aviation or the Federal Aviation Regulations (FAR) that the FAA be provided copies of these manuals. In addition, the POI stated that the FAA did not conduct line checks or en route inspections on board a foreign carrier.

FAA Order 8400.10, "Air Transportation Operations Inspector's Handbook," volume 2, chapter 4, paragraph 297, states that the purpose of surveillance of each foreign air carrier, its aircraft, and its operations is to determine compliance, on a recurrent or rotating basis, with the FARs and the foreign carrier's operations specifications. According to the FAA order, surveillance is conducted if a foreign carrier experiences "a series of accidents, incidents, violations, or complaints (that relate to safety.)" The surveillance includes any "R" (required) items specified in national program guidelines and can also include routine and unannounced ramp inspections.

Paragraph 297 of the FAA order also states that routine and unannounced ramp inspections of a foreign air carrier conducting operations with foreign-registered aircraft should be limited to those operations being conducted in the United States. The paragraph also states that the inspections should include the following items: aircraft markings; airworthiness, registration, and crewmember certificates; air traffic compliance; taxi and ramp and passenger enplaning/deplaning procedures; baggage and cargo (especially hazardous cargo); and compliance with the pilot-in-command age 60 policy, which states that a flight crewmember is prohibited from acting as pilot-in-command if he or she has reached age 60.

According to the FAA, the only "R" item required for Korean Air is one annual ramp inspection. The FAA indicated that, since 1996, Korean Air received about 201 operations inspections, 129 maintenance inspections, and 48 avionics inspections.

1.17.6.2.1 International Aviation Safety Assessment Program

The FAA established the International Aviation Safety Assessment (IASA) program in August 1992 in response to concerns^[113] about the adequacy of surveillance provided to foreign air carriers.^[114]According to an overview of the program posted on the FAA's Web site, the IASA is a foreign assessment program that "focuses on a country's ability, not the [ability of an] individual air carrier, to adhere to international standards and recommended practices for aircraft operations and maintenance established by [ICAO]." The overview indicated that "[t]he purpose of the IASA is to ensure that all foreign air carriers that operate to or from the United States are properly licensed and [are provided] safety oversight [ ] by a competent Civil Aviation Authority (CAA) in accordance with ICAO standards."^[115]

According to the overview: A foreign air carrier of a sovereign state desiring to conduct foreign air transportation operations into the United States files an application with the DOT [Department of Transportation] for a foreign air carrier permit under the Federal Aviation Act,...at 49 U.S.C. 41302.... Consistent with international law, certain safety requirements for operations into the United States are prescribed by the FAA's Part 129 regulations (14 CFR part 129). 14 CFR Part 129 specifies that the carrier must meet the safety standards contained in Part 1 (International Commercial Air Transport) of Annex 6 (Operations of Aircraft) to the Convention on International Civil Aviation (Chicago Convention). Before DOT issues a foreign air carrier permit, it notifies the FAA of the application and requests the FAA's evaluation of the respective CAA's capability for providing safety certification and continuing oversight for its international carriers.

Upon DOT notification of a pending foreign air carrier application, if the FAA has not made a positive assessment of that countr[y']s safety oversight capabilities, the FAA Flight Standards Service will direct its appropriate international field office to schedule an FAA assessment visit to the CAA of the applicant's country. Once the assessments visits have been completed, the FAA assessment team will return to the United States to compile the findings. Appropriate notifications to the CAA and other U.S. Government officials of the results of the assessments will be made from Washington, D.C., headquarters as soon as possible.

If a CAA is found to be meeting its minimum safety obligations under the Chicago Convention, the FAA will forward a positive recommendation to DOT. If there is a pending foreign carrier application, DOT will issue the requested economic authority and FAA will issue operations specifications to permit the carrier to begin operations to or from the United States.

When CAA's of countries with existing air carrier service to the U.S. are found to not meet ICAO standards, the FAA formally requests consultations with the CAA. The purpose of consultations is to discuss [the FAA's] findings in some detail and explore means to quickly rectify shortcomings found with regard to ICAO annexes, to enable its air carriers to continue service to the United States. During the consultation phase, foreign air carrier operations from that country into the United States will be frozen at existing levels.[^[116]</ref>] FAA may also heighten its surveillance inspections (ramp checks) on these carriers while they are in the United States. If the deficiencies noted during consultations cannot be successfully corrected within a reasonable period of time, FAA will notify DOT that carriers from that country do not have an acceptable level of safety oversight and will recommend that DOT revoke or suspend its carriers economic operating authority.

When CAA's of countries with no existing air carrier service to the United States are found to not meet ICAO standards, the FAA does not, of course, undertake consultations. The FAA will notify DOT that the CAA does not have an acceptable level of safety oversight and its application for economic authority will be denied. The FAA will undertake a reassessment of the CAA after evidence of compliance with ICAO provisions has been received. FAA will, of course, be willing to meet with CAA's at any time, as [ ] resources permit. After the assessment visit, consultations (if necessary), and notifications have been completed, the FAA will publicly release the results of these assessments. The FAA plans to periodically revisit CAA's of countries with air carriers operating into the United States to maintain full familiarity of the methods of that country's continued compliance with ICAO provisions. The FAA may also find it necessary to reassess a CAA at any time if it has reason to believe that minimum ICAO standards are not being met. DESIRED OUTCOME: The FAA is working to determine that each country meets its obligations under ICAO and to provide proper oversight to each air carrier operating into the U.S. The continued application of this program will result in a lower number of safety-related problems, including accidents, incidents, and an improved level of safety to the flying public.

The FAA established three ratings for the status of countries at the time of the assessment. These categories and their definitions are as follows: ?

• Category I —— Does Comply with ICAO Standards: A country's civil aviation authority has been assessed by FAA inspectors and has been found to license and oversee air carriers in accordance with ICAO aviation safety standards.

• Category II——Conditional: A country's civil aviation authority in which FAA inspectors found areas that did not meet ICAO aviation safety standards and the FAA is negotiating actively with the authority to implement corrective measures. During these negotiations, limited operations by this country's air carriers to the U.S. are permitted under heightened FAA operations inspections and surveillance.

Category III—— Does Not Comply with ICAO Standards: A country's civil aviation authority found not to meet ICAO standards for aviation oversight. Unacceptable ratings apply if the civil aviation authority has not developed or implemented laws or regulations in accordance with ICAO standards; if it lacks the technical expertise or resources to license or oversee civil aviation; if it lacks the flight operations capability to certify, oversee and enforce air carrier operations requirements; if it lacks the aircraft maintenance capability to certify, oversee and enforce air carrier maintenance requirements; or if it lacks appropriately trained inspector personnel required by ICAO standards. Operations to the U.S. by a carrier from a country that has received a Category III rating are not permitted unless they arrange to have their flights conducted with a duly authorized and properly supervised foreign air carrier appropriately certified from a country meeting international aviation safety standards.

During a June 17, 1999, briefing to Safety Board staff, the FAA indicated that, although the IASA program is intended to determine whether a foreign country's CAA is providing adequate oversight, the program does not directly assess whether foreign carriers are receiving such oversight or are complying with the provisions of Annex 6 to the Convention on International Civil Aviation. The FAA assessment team does not conduct surveillance of foreign air carriers; rather, it collects information and evaluates a foreign CAA's compliance with Annex 6 standards in seven areas: aviation law; aviation regulations; CAA structure; technical inspector workforce; technical guidance; records of certification; and records of surveillance, including followup and corrective actions.^[117] The country must be found to meet ICAO Annex 6 standards in all seven areas to be rated as Category I. The FAA offers assistance to those countries that, according to its evaluation, do not comply with ICAO Annex 6. The FAA also indicated that it has completed all of its initial assessments and that the IASA program would soon transition to "Phase 2,"^[118]which will focus on review and validation of the initial ratings and continued evaluation of the safety compliance capability of foreign CAAs.

According to the FAA, Phase 2 will be accomplished by reviewing each country's rating and all available information relevant to ICAO safety oversight requirements at least every 2 years. However, the FAA indicated that it would reevaluate a country that has air carriers operating into the United States any time there is reason to question whether that country is meeting its international safety oversight obligations. According to the FAA, Phase 2 rating decisions will be based on information gathered by the FAA, either during an on-site visit or through a questionnaire directed to the foreign CAA, or the results of an assessment by another qualified entity, such as ICAO. Also, the FAA intends to eliminate the Category III rating as part of Phase 2; accordingly, countries found not to comply with ICAO Annex 6 will be rated as Category II regardless of whether that country is conducting operations into the United States.

The KCAB was initially assessed in 1996 and was given a Category I rating. As of October 1999, the KCAB had not been reassessed.

1.17.6.3 Department of Transportation Audit Report on Aviation Safety Under International Code Share Agreements

On September 30, 1999, the Department of Transportation Office of Inspector General (DOT/IG) issued a report, titled Aviation Safety Under International Code Share Agreements (Report No. AV-1999-138). The report noted that the number of international code share agreements has more than tripled in the last 5 years and that U.S. carriers are increasingly entering into such agreements with carriers from regions of the world where aviation oversight and safety records are not as strong as those of the United States. The report found that the current process by which code share agreements are approved by the DOT does not adequately address safety implications and that the "FAA has not taken an active role in the approval or safety oversight of international code share agreements, either before or after approval." Specifically, the DOT/IG report stated:

FAA limits its input to advising [the Office of the Secretary of Transportation (OST)] about whether a foreign carrier's homeland, as distinguished from the air carrier involved, has procedures to exercise oversight of its carriers in compliance with international safety standards. FAA staff stated that if they become aware of adverse safety information about a foreign carrier, they will pass that on as well; however, they were able to provide only one example of this kind of advice, and the effort made to assess safety implications appears to be nonexistent. [The DOT/IG's] review found that the Department's current procedures require nothing of the U.S. or foreign carrier that will be parties to the agreement about the foreign carrier's safety. FAA performs no trend or other analysis, and makes no recommendations to OST, as to whether it is satisfied that there are no negative safety implications relative to the foreign carrier that will be involved in the code share agreement....

The DOT/IG's report evaluated the FAA's explanation for its limited oversight role in code share agreements. The report made the following three points:

First, FAA says it is without legal authority to make safety fitness determinations regarding individual foreign carriers. This view has merit. However, the legal situation is quite different when, as here, a U.S. carrier seeks U.S. approval to hold out to the public flights on a foreign aircraft as if they were U.S. flights and to ticket such flights in the name of a U.S. carrier. Furthermore, Federal law requires that "safety" be a paramount consideration in deciding whether to approve agreements like code shares.

Second, FAA correctly points out that it does make determinations [through the IASA program] about the civil aviation authority in the foreign carrier's homeland. This program identifies whether the carrier's homeland provides adequate aviation oversight of its carriers, and has improved international aviation safety by helping foreign civil aviation authorities improve their oversight. However, this is quite different from a judgment about the safety practices of an individual carrier. FAA is itself a civil aviation authority that meets international standards, but that is materially different from a conclusion that all U.S. carriers therefore follow sound safety practices.

The third and most legitimate point FAA raises is that it has limited resources and already is resource-constrained in exercising oversight of U.S. aircraft and U.S. crew operations. Adding code share agreements to the workload would be an additional burden and raise expectations. We believe the answer to this is that U.S. carriers seeking approval for a code share agreement can reasonably be expected to perform most of the work and provide FAA assurances that the foreign carrier that will operate as a U.S. flight is compliant with applicable safety requirements. FAA's role would be to ensure that U.S. carriers have a credible process in place to provide such assurances.

The Department of Defense (DOD) is one of the largest U.S. consumers of air carrier services because of its need to transport military personnel to locations throughout the world. According to the DOT/IG report, DOD's policy has been to use U.S. carriers for this transportation service, and DOD performs a safety review of a U.S. carrier before it can be included on an approved list of authorized military air transport providers. The report also indicated that the U.S. carriers proposed the use of foreign code share carriers for providing military transportation. Because DOD must ensure the safety of foreign code share carriers, it established a program in August 1999 with the Air Transport Association and six U.S. airlines.^[119] Under this program, the six U.S. air carriers will perform (or will arrange to have a third party perform) safety assessments of their foreign code share partners to ensure that those partners meet the legal criteria necessary to transport U.S. military personnel. The DOT/IG found that the FAA could build on DOD's program and that the FAA must ensure that safety is "a condition of initial and continued approval for international code share arrangements."

The DOT/IG report made the following recommendations to the DOT and the FAA:

• Develop and implement procedures requiring that all U.S. carriers perform safety assessments of foreign carriers as a condition of code share approval and continued authorization. These procedures should include requirements that carriers:
  • perform an initial on-site review of all existing, pending, and future code share partners;
  • establish review procedures, to be approved by FAA, that will address the content of the assessments and qualifications of staff conducting the assessments;
  • develop assessment processes that include review and verification that foreign partners have implemented effective procedures in critical safety areas such as maintenance operations, airworthiness of aircraft, crew qualifications, crew training, flight operations, en-route procedures, emergency response plans, security, and dangerous goods;
  • provide copies of safety assessments to FAA for review and acceptance, and make available to FAA, when necessary, information supporting assessment results;
  • submit confirmations from senior safety officials that the assessment results were satisfactory and any deficiencies noted have been corrected; and
  • coordinate reviews to avoid multiple assessments of foreign carriers code sharing with more than one U.S. partner.

• Coordinate closely with the Department of Defense to maximize the effective use of limited resources between the two agencies, avoid duplication, and establish protocols for the exchange of information about carrier safety assessments. FAA should also consider the safety assessment results in performing IASA reviews.

• Establish procedures for terminating or restricting the use of code share agreements when (1) the Department of Defense determines that adverse safety information warrants prohibiting U.S. military personnel from using a foreign carrier, (2) the U.S. carrier terminates the agreement, or (3) FAA, on its own initiative, makes a similar determination regarding the transport of U.S. passengers.

The DOT/IG report also recommended that the FAA

• Develop oversight procedures for FAA to validate U.S. carriers' safety assessment programs. The validation should include:
  • reviews of air carriers' audit procedures, assessment processes, and documentation supporting review conclusions to ensure the consistency, quality, and effectiveness of the review results;
  • comprehensive audits of a sample of safety assessments to confirm that carriers have applied agreed upon standards and procedures in conducting the assessments; and
  • procedures to, if necessary, perform on-site inspection of aircraft used in code share operations.

• Require that FAA staff perform risk assessments using available safety data on foreign carriers and review results of air carrier safety assessments, if made available, as part of its safety advice to OST on code share applications. This interim procedure should be used no more than 3 months, until the Department finalizes new code share procedures.^[120]

1.18 Additional Information

1.18.1 Minimum Safe Altitude Warning System

1.18.1.1 Postaccident Actions Taken by the Federal Aviation Administration

On August 15, 1997, the FAA announced in a press release that, as a "routine precaution," it had ordered MSAW testing and recertification after the Safety Board's investigation of the flight 801 accident raised questions about the MSAW's performance. The FAA reported that, of the 192 in-service^[121] MSAW software functions at radar approach control facilities, all but 2 were found to be working properly. According to the press release, the software functions were corrected, and all of the functions were recertified as operating properly. Also, in response to inquiries from Safety Board staff, the FAA created special teams of automation experts to completely examine all site adaptation parameters for the 192 MSAW systems located throughout the United States. The FAA directed ATC managers at these locations to document and report any MSAW problems. Further, the FAA's Associate Administrator for Air Traffic Services directed a factfinding review of MSAW equipment and operational procedures at 10 ATC towers The review included a survey of 105 air traffic personnel and 33 airway facilities personnel.

According to the FAA's executive summary of the MSAW fact-finding review (dated September 1997), "air traffic staff and operational personnel, except for those with automation training, claimed little knowledge of the parameters or components that make up MSAW." The executive summary indicated that very few of the air traffic survey respondents could remember receiving facility training about different MSAW areas and that most reported that their only MSAW training was an overview during the initial air traffic course.

According to the executive summary, the air traffic survey respondents indicated that a check of the MSAW aural alarm was required at the beginning of each shift, but they gave varying answers concerning what should be done if the MSAW was not functioning properly. Likewise, these survey participants believed that controllers should issue an advisory if an aircraft generates an MSAW alert, but the participants were not consistent in their answers regarding who was responsible for responding to the MSAW alert at a satellite tower. In addition, the air traffic personnel in the survey gave different answers regarding who had the authority to adjust MSAW parameters and "vague" answers regarding MSAW general notices.

All of the airways facilities personnel in the survey indicated that daily functional checks of aural MSAW alarms were required, and they knew where this check was documented. However, these personnel gave varying answers concerning how they would complete the check if an MSAW system were inhibited. Further, these respondents indicated that their MSAW training ranged from initial hardware training and on-the-job training to only on-the-job training for those personnel who completed initial schooling before the MSAW system was implemented.

The fact-finding review also found that the ARTS IIA and IIIE parameter documentation was unclear and confusing to automation specialists and that there were "no guidelines or standards defined in any document concerning the proper way to adapt the MSAW site variables." The survey revealed that, as a result of inadequate reference material, the MSAW altitudes at one ATC tower and two TRACONs were set incorrectly. These facilities had adapted the MSAW approach path monitor altitudes to be agl values when the system was intended to provide msl values. As a result, all the altitudes used for the MSAW system were hundreds of feet too low at the ATC tower and one of the TRACON facilities; the altitude discrepancy at the other TRACON was "negligible" because of its approximate sea level elevation.

On the basis of its fact-finding review, the FAA made several internal recommendations, including the following:

• a standardized comprehensive training program should be established to provide a basis for entry-level and periodic refresher training in the operation and maintenance of MSAW equipment, and a certification process should be established for personnel who have completed this training;
• uniform site adaptation/system parameters should be established for MSAW equipment operation;
• provisions for periodic evaluation of MSAW equipment should be established to ensure system integrity and reliability; and
• configuration management of all software should be reflected in appropriate documents and centrally controlled.

In addition, in an October 1997 briefing to Safety Board investigators, FAA officials presented the agency's planned corrective actions for the national MSAW system. The officials stated that the FAA was developing a central oversight process for the MSAW program and that MSAW systems would be flight checked and ground certified as part of the commissioning process for a new radar and then periodically thereafter. Further, the officials said that the FAA had approved a new MSAW software management policy that "established strict management oversight and control" for MSAW software modifications.

1.18.1.2 Previous Safety Board Recommendations on the Minimum Safe Altitude Warning System

The Safety Board has issued numerous safety recommendations regarding the MSAW system. Recent MSAW safety recommendations have addressed the installation of MSAW equipment in VFR terminal facilities that receive radar information from a host radar control facility (as is the case with the Agana tower), as well as the inspection and testing of MSAW speakers to ensure the integrity of MSAW systems.

Development of an MSAW System (A-73-46)

On December 29, 1972, Eastern Air Lines flight 401, a Lockheed L-1011, N310EA, crashed near Miami, Florida. In its final report,^[122] the Safety Board stated that its investigation ...revealed another instance where the ARTS III system conceivably could have aided the approach controller in his ability to detect an altitude deviation of a transponder-equipped aircraft, analyze the situation, and take timely action...to assist the flight crew. In this instance, the controller, after noticing on his radar that the alphanumeric block representing flight 401 indicated an altitude of 900 feet, immediately queried the flight as to its progress. An immediate positive response from the flight crew, and the knowledge that the ARTS III equipment, at times, indicates incorrect information for up to three scans, led the controller to believe that flight 401 was in no immediate danger.

As a result of its findings, the Safety Board issued Safety Recommendation A-73-46, which asked the FAA to

Review the ARTS III program for the possible development of procedures to aid flight crews when marked deviations in altitude are noticed by an air traffic controller.

In a May 31, 1977, letter, the FAA advised the Safety Board that an MSAW system had been developed as an integral function of the ARTS III program and that controllers had received guidance on its use. On September 16, 1977, the Safety Board classified Safety Recommendation A-73-46 "Closed--Acceptable Action."

Minimizing MSAW Inhibited Areas (A-90-130)

On September 8, 1989, USAir flight 105, a 737-200, N283AU, struck four electronic transmission cables while executing the localizer backcourse approach to runway 27 at Kansas City International Airport in Kansas City, Missouri.^[123] The Safety Board's final report on this incident concluded that, although the Kansas City airport's ATC facility was equipped with MSAW software, the MSAW alert failed to activate during the premature descent of flight 105 because the descent had occurred more than 1 mile from the runway threshold and inside an area that had been designed to inhibit the MSAW to reduce false alerts. The Safety Board's report said that "...this incident indicates the need to revise the parameters controlling the size of the MSAW inhibit areas." The report urged the FAA "to provide site adaptations guidance to encourage modification of MSAW parameters, as appropriate, to increase the MSAW protection areas and to minimize the extent of inhibited areas." On the basis of its findings, the Safety Board issued Safety Recommendation A-90-130, which asked the FAA to

Provide site adaptation guidance to encourage modification of Minimum Safe Altitude Warning parameters, as appropriate, to minimize the extent of inhibit areas.

In an October 6, 1993, letter, the FAA stated that it had issued a change to FAA Order 7210.3K, "Facility Operation and Administration," which provided for site adaptation guidance to minimize the extent of MSAW inhibited areas. Because the FAA's response met the intent of Safety Recommendation A-90-130, it was classified "Closed-- Acceptable Action" on January 28, 1994. MSAW Site Variables and Capture Boxes (A-94-187)

On June 18, 1994, a Transportes Aereos Ejecutivos, S.A. (TAESA) Learjet 25D, operating under 14 CFR Part 129, was executing an ILS approach in IMC when the airplane crashed 0.8 nm south of the runway 1R threshold at Dulles International Airport, Chantilly, Virginia.^[124] The 2 flight crew members and all 10 passengers were killed. The Safety Board's investigation determined that the accident airplane did not generate any MSAW alerts while on the approach to the airport. The investigation also determined that the MSAW site variable parameters at the airport required two "current position" radar returns or three "predicted position" radar returns below the 500-foot floor before the aural and visual alerts would activate. A review of the radar data revealed that the airplane generated one radar return below the alert altitude of the runway 1R MSAW capture box.

The Safety Board's investigation of this accident revealed discrepancies with the airport's MSAW equipment.^[125] Specifically, the MSAW site variable parameters for runway 1R indicated a discrepancy between the MSAW-defined runway location and the actual threshold location. The FAA said that, when the ARTS III software was programmed for a 10° west variation (the angular difference between true north and magnetic north at Dulles Airport), the computed position for the runway threshold did not correlate to the actual geographic runway location. Further, the "radar-established" runway position was 700 feet northeast of the actual runway threshold. The Safety Board found that the error in the radar position for the runway 1R threshold resulted in a similar displacement of the radar MSAW capture box from its intended position with the actual approach path to runway 1R. The Safety Board concluded that such displacement might compromise the protective intent of the MSAW system.

On November 21, 1994, the Safety Board issued Safety Recommendation A-94-187, which asked the FAA to Conduct a complete national review of all environments using MSAW systems. This review should address all user-defined site variables for the MSAW programs that control general terrain warnings, as well as runway capture boxes, to ensure compliance with prescribed procedures.^[126]

In a March 20, 1995, letter, the FAA stated that it planned to review the MSAW site variables to ensure compliance with prescribed procedures. According to the FAA, the review would address all user-defined site variables for the MSAW program that control general terrain warnings, as well as runway capture boxes, to ensure compliance. The FAA stated that its review of 190 ATC facilities (128 operational ARTS IIA and 62 operational ARTS IIIA sites) would begin in April 1995 and be concluded by July 1995. On November 20, 1995, the Safety Board stated its concern that the FAA's review process for the 190 ATC facilities with MSAW was taking longer than originally anticipated.

On January 26, 1996, the FAA stated that it had completed its review of the 190 ATC facilities. Further, the FAA stated that, as of October 1995, proper alignment of the MSAW capture boxes had been verified at all 128 ARTS IIA and 62 ARTS IIIA sites.^[127] On April 8, 1996, the Safety Board stated that, because this action met the intent of Safety Recommendation A-94-187, it was classified "Closed--Acceptable Action."

MSAW Aural Alerts in VFR Facilities (A-95-120)

On January 29, 1995, a Beechcraft A36 crashed during a missed ILS approach to DeKalb-Peachtree Airport in Chamblee, Georgia.^[128] The pilot, the sole occupant of the flight, was killed. The Safety Board determined that, before the accident, the airport tower had received four MSAW general terrain warning alerts from the Atlanta TRACON, which was providing approach control services. The tower was equipped with a D-BRITE radar display with visual MSAW alerting only.^[129]

The Safety Board's investigation found that, if a full MSAW system (including an aural alert) had been installed in the DeKalb-Peachtree tower, the controller would have received an aural MSAW alert along with the visual alert that had been depicted on the radar. Further, the tower controller told Board investigators that he did not observe the visual MSAW alert on the D-BRITE because he had been involved with other duties before the accident that did not allow him to continually monitor the data block for the airplane.

As part of its investigation into the accident, on February 8, 1995, the Safety Board requested that the FAA provide its policy on installation of aural MSAW alerts at low-density ATC towers equipped with D-BRITE radar displays. On June 27, 1995, the FAA stated that "...no policy exists for the operation of an aural alarm associated with MSAW in VFR towers that are not combined with full radar approach control facilities."

On November 30, 1995, the Safety Board issued Safety Recommendation A-95-120, which asked the FAA to Within 90 days from the receipt of this letter, develop a policy that would require the installation of aural minimum safe altitude warning (MSAW) equipment in those visual flight rules terminal facilities that receive radar information from a host radar control facility and would otherwise receive only a visual MSAW alert.

On February 21, 1996, the FAA stated that it would conduct a cost-benefit analysis to determine the feasibility of implementing this safety recommendation. The FAA further stated that the analysis would be completed by the end of March 1996. In June 1996, the FAA completed the cost-benefit analysis and determined that it was feasible to implement the recommendation. The FAA expected that implementation would be accomplished by the end of March 1997.

In its July 15, 1996, letter to the FAA, the Safety Board stated that, although the FAA's implementation of the requirement for the aural alert was not accomplished within the 90 days specified in the safety recommendation, the Board was pleased that the FAA had proceeded with the implementation. The Board indicated that it would wait to receive a list of the affected facilities and anticipated installation dates.

On July 31, 1997, the FAA stated that it had conducted a survey to determine the total number of ATC facilities that did not have aural MSAW alerts installed. The FAA found that 43 remote displays had been equipped with aural alarms but that 69 remote displays did not have aural alarms. The FAA anticipated that the aural alarms at those 69 remote displays would be implemented by February 1998.

On December 30, 1997, the Safety Board said that it was encouraged that the FAA was moving forward and urged the FAA to keep the program on track and within its anticipated milestones. On May 14, 1998, the FAA said that, as of April 10, 1998, kits had been delivered to all 69 remote sites and that all alarms would be operational during May 1998. However, at the Safety Board's public hearing in March 1998, the FAA's Deputy Director for Air Traffic Operations testified that the new projected completion date for installation of aural alarms at VFR towers, including the tower at Guam, was April 2000.

On October 19, 1998, the Safety Board stated that the primary intent of this recommendation was to ensure that VFR tower controllers who have a visual representation from a distant host radar receive an aural alert when aircraft under their control and with whom they are in radio communication descend below the minimum safe altitude. If the tower controller was engaged in visually scanning for other aircraft, the aural alert would allow the controller to determine the aircraft call sign and transmit the appropriate warning to the pilot. The Board's letter indicated that the FAA was unclear about whether controllers at VFR terminal facilities would receive an aural alert for those aircraft with whom they are in communication. Further, Safety Board staff had determined that, in at least one location, the VFR tower would not receive an aural warning. (The Board's letter did not identify the location of this facility.) The Board requested that the FAA ensure that controllers at all VFR towers with visual representation systems from a distant host radar receive an aural alert when aircraft within their traffic pattern and with whom they are in communication descend below the minimum safe altitude. Pending the receipt of this information from the FAA, Safety Recommendation A-95-120 was classified "Open--Acceptable Response."

On September 29, 1999, a representative from the FAA stated that the agency's management had indicated that the Agana tower was currently receiving aural MSAW alerts. At an October 7, 1999, briefing attended by the FAA Administrator, the Safety Board Chairman, and staff from both agencies, the FAA indicated that 69 MSAW aural alarms had been delivered and that 51 alarms were to be delivered. The FAA expected that the acquisition of these 51 alarms would be completed by October 2000 and that their installation in VFR towers would be completed by April 2001.

On October 12, 1999, the FAA Program Director for Serco Aviation Services told Safety Board staff that the Agana tower has the capability to receive an aural MSAW alert but that, unless the Guam CERAP transfers responsibility for the aircraft's data block, the tower will not receive the aural warning. The official added that the CERAP does not currently transfer responsibility for the aircraft's data block to the Agana tower; therefore, the tower does not receive an aural MSAW alert.

On October 14, 1999, the FAA Program Director for Air Traffic Operations confirmed that Agana tower was not receiving aural MSAW alerts. In an October 15, 1999, facsimile, the program director indicated that the Agana tower "has the software and hardware capability in place to receive aural alarms." The director further indicated that the FAA had issued a policy "to ensure that the facility that is in direct radio communications with the aircraft receives the aural alarm" and that the policy would become effective by November 15, 1999. (The FAA subsequently indicated that, under the new procedures, the Guam CERAP would transfer responsibility for the aircraft's data block to the Agana tower and that the aural MSAW alert would be transferred to the tower upon its acceptance of the transfer of the data block. The tower would advise the CERAP after an MSAW alert was issued.) The program director stated, in a followup telephone conversation with the Safety Board's Director of the Office of Aviation Safety, that a national policy would be issued to ensure that procedures similar to those being implemented at Guam are followed at other VFR towers.

On October 25, 1999, the FAA indicated that the MSAW aural alarms for the ARTS IIA system at Guam were reconfigured on October 24, 1999. The FAA stated that, in the event of a low-altitude alert for an aircraft operating in the vicinity of Guam International Airport, aural alarms will be simultaneously generated at the CERAP and the Agana tower, along with visual low-altitude alerts on the radar displays at both facilities.

On November 2, 1999, the Safety Board received a copy of draft FAA Notice N7210.485, "Minimum Safe Altitude Warning for Remote Tower Displays." According to the notice, facility managers at ATC towers that have aural alarms for MSAW are to ensure that "the operational support facility has adapted the software functionality to ensure the aural alarms operate in the ATCT [air traffic control tower]" and that "aural alarms are received in the ATCT upon transfer of communications." The FAA indicated that the effective date for this notice would be February 1, 2000. The Safety Board's evaluation and classification of Safety Recommendation A-95-120 are discussed in section 2.6.2.

Inspections and Tests of MSAW Speakers and the Standard Terminal Automation Replacement System Program (A-97-22 Through A-97-27)

On October 2, 1996, a Piper PA-32-300, N2881W, crashed in a heavily wooded area in Brandywine, Maryland, while on approach to Washington Executive/Hyde Field Airport in Clinton, Maryland.^[130] The pilot and two passengers were killed, and the airplane was destroyed. According to MSAW data retrieved from the Washington National TRACON, the accident airplane generated four general terrain warning MSAW alerts during the approach to the airport. A controller-in-training and a fully certified instructor were providing ATC services to the accident airplane from the TRACON's F-2 radar position. In a postaccident interview, both controllers stated that they did not recall seeing or hearing any MSAW alerts. Several other controllers and a supervisor who were stationed at nearby positions about the time of the accident also stated that they did not recall hearing or observing any low-altitude warnings before the accident.

As part of the Safety Board's investigation of this accident, a Board investigator toured the TRACON radar room to observe the control position that provided ATC services to the accident pilot. During this tour, the investigator noted that the MSAW aural alarm speaker, located directly above the F-2 radar position (and the only MSAW speaker in the radar room), was covered with heavy paper held in place with what appeared to be masking tape.

On the basis of its findings during this accident, the Safety Board issued Safety Recommendations A-97-22 through -27 on April 16, 1997. Safety Recommendations A-97-22 and -23 asked the FAA to

Immediately issue an urgent general notice to all affected air traffic managers, directing them to conduct an immediate visual inspection and aural test of the aural minimum safe altitude warning speakers in their facilities to ensure that no devices have been placed over them that might hinder, mute, or prevent the aural warning from being heard in the operational quarters. (A-97-22)

Require that a daily visual inspection and aural test of the minimum safe altitude warning (MSAW) speakers located in the operational quarters be conducted by supervisory personnel prior to the start of each shift to ensure the integrity of the MSAW system. Require that these inspections be recorded in the appropriate facility logs. (A-97-23)

On July 1, 1997, the FAA stated that it agreed with the intent of Safety Recommendations A-97-22 and -23. The FAA stated that, on May 7, 1997, it had ordered air traffic division managers to brief facility managers on the issue of muted MSAW speakers and instructed supervisors to conduct a visual inspection of MSAW speakers and remove "any muting devices" from these speakers. In addition, the FAA issued a general notice on June 7, 1997, to implement the requirement for supervisors to check the MSAW speakers as part of the shift checklist and record the completion of this inspection on the appropriate facility logs. The FAA also revised Order 7210.3, "Facility Operation and Administration," to reflect the change in policy and procedures.

On February 27, 1998, the Safety Board stated that, because the actions taken by the FAA addressed the intent of Safety Recommendations A-97-22 and -23, they were classified "Closed--Acceptable Action."

Safety Recommendation A-97-24 asked the FAA to

Require that all affected terminal personnel be briefed on the contents of this safety recommendation letter. This briefing should focus on generating awareness and vigilance in those situations in which a safety alert might occur and controllers must be prepared to respond, as directed in FAA Order 7110.65, "Air Traffic Control."

On July 1, 1997, the FAA stated that it complied with this safety recommendation in a June 9, 1997, memorandum to facility managers, requiring that controllers be briefed on how to respond to MSAW alerts. The facility managers were directed to ensure, within 2 weeks after the receipt of the memorandum, that all operational personnel were briefed on the requirements of FAA Order 7110.65, "Air Traffic Control," paragraph 2-1-1, "Duty Priority;" 2-1-6, "Safety Alerts;" and 5-15-57, "Inhibiting Minimum Safe Altitude Warnings (MSAW)." All operational personnel were also expected to be briefed on the actions to be taken when controllers are alerted by the MSAW of an aircraft's proximity to terrain.

On February 27, 1998, the Safety Board stated that it had received a copy of the FAA's June 9, 1997, memorandum but that, in light of the Korean Air flight 801 accident on August 6, 1997, the Board had not received written confirmation that the actions directed by the memorandum were completed for the Guam ATC facilities. On September 25, 1998, the FAA stated that it had accomplished the briefing to Guam ATC facility personnel on July 18, 1997. As a result, the Safety Board classified Safety Recommendation A-97-24 "Closed--Acceptable Action" on January 14, 1999.

Safety Recommendation A-97-25 asked the FAA to

Modify the software for the minimum safe altitude warning system to enhance conspicuity of those aircraft that may require the controller's immediate attention and action. Such modifications might be accomplished by placing the target and data block within a flashing circle.

The FAA stated in its July 1, 1997, letter that it reviewed the feasibility of modifying the software for the MSAW system to enhance the conspicuity of the data block. The FAA concluded that the existing MSAW processing generated sufficient alarms and was completely adequate; thus, no further action would be necessary.

On February 27, 1998, the Safety Board stated that it was disappointed with the FAA's response to this safety recommendation and the FAA's continued belief that the design of the current MSAW visual display is adequate. Further, the Safety Board stated that the evidence in the Brandywine, Maryland, accident clearly demonstrated that multiple MSAW visual and aural warning alerts were generated in the operational quarters of the TRACON but that the controller failed to respond to these alerts. The Safety Board believed that the FAA should reconsider its position not to remedy the deficiencies that led to the issuance of this recommendation.

On September 25, 1998, the FAA stated that color displays, now under development for the Standard Terminal Automation Replacement System (STARS), would provide the increased conspicuity suggested in this safety recommendation. According to the FAA, the STARS early display configuration initial operational capability was scheduled for Ronald Reagan Washington National Airport in March 1999, and the early display configuration operational readiness demonstration was scheduled for June 1999. The early display configuration was to include the color red for alerts in addition to flashing data blocks. All ARTS data, except for alerts, would be monochrome.

On January 14, 1999, the Safety Board stated that, pending the commissioning of STARS and the FAA's inclusion of the flashing red MSAW display feature in the system's final operational configuration, Safety Recommendation A-97-25 was classified "Open-- Acceptable Response."

On August 13, 1999, the FAA stated that the delivery of STARS had been delayed. The FAA indicated that, on April 26, 1999, it announced a revised plan for the STARS program. According to the revised plan, the STARS early display configuration (which includes existing MSAW capability) is to begin initial operations at Syracuse, New York, and El Paso, Texas, in December 1999 and January 2000, respectively. Also, the FAA stated that, as part of the revised plan, it would procure ARTS color displays (which display the alert data blocks in flashing red) for the largest TRACONs and any new facilities while STARS development continues. The ARTS color displays are scheduled to begin operations at the New York TRACON in August 2000.

The FAA indicated that, when the STARS full-service system is deployed, the MSAW alerts will flash in red. However, the FAA stated that it did not plan to modify the existing MSAW system as requested in this safety recommendation because the existing system provides both aural and visual alarms and is completely adequate when operated according to design.

On November 3, 1999, the Safety Board stated that it was deeply concerned about the significant delay in fielding STARS and that it could not continue to maintain the classification of this recommendation, which was evaluated to be "Open--Acceptable Response" in January 1999, if the implementation of STARS according to its current schedule was the FAA's only means for complying with the recommendation. The Board urged the FAA to expedite the implementation of STARS by significantly accelerating the current schedule. The Board also urged the FAA to reconsider its position on modifying existing MSAW software if the STARS implementation schedule cannot be accelerated. Pending the FAA's reconsideration of this issue or a change in the implementation schedule for STARS, Safety Recommendation A-97-25 remained classified "Open-- Acceptable Response."

Safety Recommendation A-97-26 asked the FAA to

Require that the Standard Terminal Automation Replacement System program include a minimum safe altitude warning (MSAW) speaker at each radar display, a capability for the controller to momentarily override and mute an MSAW alert, and a computerized recording of the muting of such an alert.

On July 1, 1997, the FAA outlined the specifications for STARS and the MSAW system. On February 27, 1998, the Safety Board stated its belief that, for those aircraft that qualify under the MSAW system as part of the routine ATC services, the controller should not be given the option to permanently inhibit the MSAW processing. The Board clarified the intent of this safety recommendation by restating that the controller should be permitted to temporarily mute an alert to acknowledge that warning was received and then act on such an alert, if required. Further, the Board stated that, although the FAA provided specifications regarding the STARS and MSAW system, it did not address the intent of the recommendation.

On September 25, 1998, the FAA said that STARS terminal controller workstations and tower display workstations contained individual aural alarm speakers and that STARS would permit MSAW alert inhibits for either a specified aircraft or workstation. The FAA also stated that STARS was designed to permit temporary inhibits resulting from specific aircraft operation characteristics or possible system malfunctions and that all inhibit actions would be recorded. According to the FAA, STARS allows a controller to silence a routine aural alert by hitting an "acknowledge" key. The FAA indicated that, although the aural alarm would be silenced, the alert would remain displayed until the violation condition ceased. On January 14, 1999, the Safety Board stated that, because STARS incorporated all components suggested in Safety Recommendation A-97-26, it was classified "Closed--Acceptable Action."

Safety Recommendation A-97-27 asked the FAA to

Require, under the Standard Terminal Automation Replacement System program, that minimum safe altitude warning alerts on instrument flight rules aircraft be duplicated at a position in the operational quarters designated for supervisory personnel and that the supervisor determine the validity of the alert and whether appropriate corrective action has been initiated or is required.

The FAA's July 1, 1997, letter indicated that there is no operational requirement under STARS to duplicate MSAW alarms at supervisory positions. The FAA also stated that supervisory positions did not include controller displays and that it did not plan to provide displays to supervisory personnel. According to the FAA, STARS would provide a supervisor with the ability to monitor MSAW alerts immediately from every controller position that displays an alert.

On February 27, 1998, the Safety Board stated its understanding that the current STARS operational documentation contained no requirement to duplicate the MSAW alerts at supervisory positions and that STARS would provide a supervisor with the ability to monitor MSAW alerts immediately from every controller position that displays an alert. The Board explained that it was not the intent of this recommendation to have a controller workstation be designed for the supervisor but rather to enable the supervisor to be "in the loop" if an MSAW alert was generated. The Board believed that such an arrangement would serve as a form of redundancy that could enhance the benefits of the MSAW system and STARS.

In its September 25, 1998, letter, the FAA stated that supervisors should be aware whenever MSAW alerts are generated. Further, the FAA stated that, in STARS, supervisor awareness of MSAW events is accomplished through aural alarms at each controller position. According to the FAA, supervisors are expected to be on the control room floor to monitor all areas of the operation, including MSAW alerts, and are expected to spend a minimal amount of time at supervisory workstations.

On January 14, 1999, the Safety Board stated that the individual aural alert speakers located at each controller position should alert a supervisor to the sector experiencing an MSAW alert. Therefore, supervisors should be able to react to each alert from their workstation or throughout the operating floor. Because the intent of Safety Recommendation A-97-27 was satisfied in an alternative manner, it was classified "Closed--Acceptable Alternate Action."

1.18.2 Traditional and Enhanced Ground Proximity Warning Systems

1.18.2.1 Traditional Ground Proximity Warning System Traditional GPWS uses numerous input signals to determine if a terrain collision threat exists.^[131] Inputs from the aircraft systems include the radio altitude,^[132] descent rate and airspeed, landing gear position, landing flap position, and glideslope information. This information generates the visual and aural annunciations to the flight crew. GPWS uses the radio altimeter to calculate closure rate with terrain to predict a potential collision threat. However, if the terrain rises steeply (for example, a sheer cliff), the system cannot provide a timely warning to the flight crew. The optional altitude callout advisories generated by GPWS are the aircraft's altitude above the ground as calculated by the radio altimeter.

1.18.2.2 Enhanced Ground Proximity Warning System Enhanced GPWS has the ability to "look ahead" of the aircraft to determine the terrain elevation along the flightpath. Enhanced GPWS can therefore provide pilots with visual and aural alerts in advance of an impending impact with terrain, thus allowing pilots more time than with traditional GPWS to determine the necessary corrective actions to be taken.^[133]

Enhanced GPWS compares the aircraft's position, as determined by its on-board navigational systems (that is, the flight management system [FMS], inertial reference system, or GPS), with a stored terrain database. Terrain and ground obstructions that may pose a collision threat along the flightpath of the aircraft result in aural and visual warnings. The visual warning information is provided to the pilot using the color graphics capabilities of a dedicated display screen, the color weather radar, or an Electronic Flight Instrument System map display (depending on the particular installation).

Further, unlike traditional GPWS, enhanced GPWS utilizes an airport position database to establish a "terrain clearance floor" around all airports. This feature ensures sufficient terrain clearance regardless of the airplane's landing gear and flap configuration.

1.18.2.2.1 Notice of Proposed Rulemaking for Enhanced Ground Proximity Warning Systems

On August 26, 1998, the FAA issued a notice of proposed rulemaking (NPRM) addressing the development and installation of a TAWS^[134] (Docket No. 29312, Notice No. 98-11). The NPRM stated that Technical Standard Order (TSO) C151, titled "Terrain Awareness and Warning System," was being developed through the FAA's TSO process and that, once the TSO has been completed, the FAA would issue an advisory circular (AC)^[135] addressing an acceptable means of obtaining installation approval.

The FAA believed that the installation of a TAWS would ensure that all applicable airplanes operated under Parts 91, 121, and 135 would have state-of-the-art equipment to aid in the prevention of CFIT accidents. The FAA's proposal also applies to operators conducting flights under Part 125 and operators of U.S.-registered airplanes under Part 129.

The FAA proposed that, for operations conducted under Part 121, the rule would apply to all turbine-powered airplanes and that, for operations under Parts 91, 125, 129, and 135, the rule would apply to all turbine-powered airplanes type certificated to have six or more passenger seats, excluding any pilot seat. (The FAA stated in the NPRM that the proposed rule applied only to turbine-powered airplanes, but the FAA indicated that it would consider comments on whether the installation of a TAWS on reciprocating enginepowered airplanes should be required. The FAA also stated that it would study data and information submitted by respondents before making a determination whether TAWS should be required for reciprocating engine-powered airplanes.)

The FAA proposed that, beginning 1 year after the effective date of the final rule, U.S.-registered turbine-powered airplanes manufactured after that date be equipped with TAWS and that existing turbine-powered airplanes be equipped with TAWS within 4 years after the effective date of the final rule. The FAA also proposed to amend 14 CFR Sections 121.360 and 135.153 to add an expiration date of 4 years after the effective date of the final rule for the use of current GPWS systems; thereafter, compliance with those sections would not be allowed instead of the provisions proposed within the NPRM. In addition, the FAA's proposal would also require operators to include in their airplane flight manuals the appropriate procedures for operating and responding to the audio and visual warnings of the TAWS.

In a December 24, 1998, letter to the FAA, the Safety Board indicated that the NPRM, if promulgated, would have a positive effect on aviation safety by reducing the possibility for CFIT accidents. However, on May 12, 1999, the Safety Board concluded that the 4-year installation time frame proposed by the FAA should be shortened to 3 years for airplanes that currently lack any GPWS protection (see section 1.18.2.4).

The FAA indicated that it expected to issue the final rule by March 2000, with an effective date 1 year after the date of issuance. According to the FAA, the final rule would mandate the installation and use of TAWS within 1 year after the effective date on new-production airplanes and within 4 years after the effective date for existing airplanes.

1.18.2.3 Department of Transportation Studies on Traditional and Enhanced Ground Proximity Warning Systems

In 1995, the FAA commissioned the DOT's Volpe National Transportation Systems Center to examine the effectiveness of GPWS and enhanced GPWS in preventing CFIT accidents in 14 CFR Part 91 operations. The center studied 44 CFIT accidents that occurred between 1985 and 1994 and involved airplanes operating under 14 CFR Part 91 with 6 to 10 passenger seats. Of the 44 airplanes, 11 were turbojets and 33 were turboprops, and none of the airplanes had GPWS installed.^[136] The center used computer modeling techniques to conclude that (1) GPWS could have prevented 33 of the 44 accidents (75 percent) and 96 fatalities and (2) enhanced GPWS could have prevented 42 of the 44 accidents (95 percent) and 126 fatalities.^[137]

Later in 1996, the FAA commissioned the DOT's Volpe National Transportation Systems Center for a second study that examined the effectiveness of GPWS and enhanced GPWS in preventing CFIT accidents involving airplanes operating under 14 CFR Part 121 and 135 or their foreign equivalents. The center studied 47 domestic and 104 foreign CFIT accidents that occurred between 1985 and 1995; 38 of the domestic accidents and 96 of the foreign accidents involved fatalities. The center developed a methodology and scheme for selecting a representative sample, and nine accidents were selected for detailed study and analysis.

The Volpe center found that four of the nine accidents (44 percent) should have been prevented by the basic GPWS equipment that had been installed. In two of these four accidents, the GPWS equipment either was disconnected or malfunctioned; in the other two accidents, poor flight crew coordination after the GPWS warning led to inaction rather than decisive recovery maneuvers.

The Volpe center further found that, for all nine accidents, enhanced GPWS would have provided more warning time than GPWS (which was assumed to be 12 to 15 seconds). For seven of the accidents, warning times with enhanced GPWS would have exceeded those of GPWS by more than 20 seconds; two of the accidents would have involved differences of more than 1 minute. The center concluded that "in general, [enhanced GPWS] should have provided an additional margin in which flight crews could assess their situation, discover errors, regain situational awareness, and take appropriate action before impact." The center noted only one accident for which an assumed enhanced GPWS warning duration would have been only slightly above the 12- to 15-second GPWS warning. The center argued that this case, which involved a pilot's fatal wrong turn toward mountains, might have been prevented by the visual forward-looking terrain display installed in enhanced GPWS. Thus, the center believed that it was reasonable to assume that enhanced GPWS could have prevented all nine (100 percent) of these accidents.

The Part 121 and 135 study credited GPWS as a significant factor in reducing the frequency of CFIT accidents since 1975. However, the center concluded that "there is compelling evidence of the potential effectiveness of [enhanced GPWS] in preventing CFIT accidents." The study emphasized that CFIT accident prevention would result not only from the increased warning time after the enhanced GPWS detected terrain threats but also from the system's continuous terrain display, which would enable flight crews to perceive terrain threats and respond to them well before enhanced GPWS would generate its warnings.^[138]

1.18.2.4 Previous Safety Board Recommendations on Traditional and Enhanced Ground Proximity Warning Systems

In 1971, the Safety Board began issuing numerous recommendations to the FAA regarding the installation and upgrade modification of GPWS. (The FAA first mandated the installation of GPWS in 1974 for all 14 CFR Part 121 carriers.) More recently, the Safety Board has issued recommendations addressing the additional benefits of installing enhanced GPWS.

GPWS Development (A-71-53, A-72-19, and A-72-35)

On February 17, 1971, a Southern Airways Douglas DC-9-15, N92S, struck an electric transmission line static cable during a VOR approach to runway 31 at the Municipal Airport in Gulfport, Mississippi ^[139] A successful missed approach was accomplished, and the aircraft landed safely. On the basis of the results of its investigation, the Safety Board issued Safety Recommendation A-71-53, asking the FAA to

Develop a ground proximity warning system for use in the approach and landing phases of operation, which will warn flight crews of excessive rates of descent, unwanted/inadvertent descent below minimum descent altitudes, or descent through decision heights. It would be desirable if the equipment now installed could meet this need.

The FAA responded that it believed that "the present instrumentation and procedures are safe and adequate provided cockpit disciplines are maintained." The Safety Board subsequently classified this recommendation "Closed--No Longer Applicable" because it was superceded by Safety Recommendation A-72-19. That recommendation was issued as a result of the June 22, 1971, accident involving a Northeast Airlines McDonnell Douglas DC-9-31, N982NE, which struck the water during a nonprecision instrument approach to runway 24 at the airport at Martha's Vineyard, Massachusetts.^[140] The Safety Board issued Safety Recommendation A-72-19, asking that

The Administrator require all air carrier aircraft to be equipped with a functional ground proximity warning device, in addition to barometric altimeters.

On November 14, 1972, Southern Airways charter flight 932, a DC-9, N97S, crashed during a nonprecision instrument landing approach to runway 11 at the Tri-State Airport, Huntington, West Virginia.^[141] The airplane impacted trees on a hill approximately 1 mile west of the runway threshold. All 71 passengers and 4 crewmembers were killed, and the airplane was destroyed. As a result of its investigation, the Safety Board issued Safety Recommendation A-72-35 to the FAA, asking that

The Administrator evaluate the need for the installation and use of ground proximity warning devices on air carrier aircraft. In its November 2, 1973, letter to the FAA, the Safety Board classified Safety Recommendation A-72-19 "Closed--Acceptable Alternate Action." Also, the Board classified Safety Recommendation A-72-35 "Closed--No Longer Applicable" in the same letter.

GPWS Installation for 14 CFR Part 135 Operations (A-86-109)

On August 25, 1985, Bar Harbor Airlines flight 1808, a Beech B99, N300WP, crashed during an ILS approach to Auburn-Lewiston Airport, Auburn, Maine. The airplane struck trees at an elevation of 345 feet msl in a wings-level attitude 4,000 feet from the end of the runway threshold and 440 feet to the right of the extended runway centerline. All eight airplane occupants were killed.

On September 23, 1985, Henson Airlines flight 1517, a Beech B99, N339HA, crashed during an ILS approach to Shenandoah Valley Airport, Weyers Cave, Virginia. The airplane struck trees at an elevation of 2,400 feet msl in a wings-level attitude about 6 miles east of the airport. All 14 airplane occupants were killed.

On March 13, 1986, Simmons Airlines flight 1746, an Embraer EMB-110P1, N1356P, crashed during an ILS approach to Phelps Collins Airport, Alpena, Michigan. The airplane struck trees at an elevation of 725 feet msl in a wings-level attitude about 1 ½ miles from the end of the runway threshold and about 300 feet to the left of the extended runway centerline. Three of the nine airplane occupants were killed, five occupants received serious injuries, and one occupant received minor injuries.

The Safety Board's investigation of these accidents revealed that the accidents occurred while the airplanes were in controlled flight and the flight crews were attempting to complete precision instrument approaches in IMC.^[142] None of the flight crews indicated that they were experiencing airplane or equipment problems, and none of the postaccident examinations disclosed airplane or equipment problems that would explain the accidents. As a result of these three accidents, the Safety Board issued Safety Recommendation A-86-109, which asked the FAA to

Amend 14 CFR Section 135.153 to require after a specified date the installation and use of ground proximity warning devices in all multiengine, turbine-powered fixed-wing airplanes, certificated to carry 10 or more passengers.

On January 8, 1987, the FAA stated that it initiated a proposed regulatory project for the development of an NPRM for a GPWS requirement for 14 CFR Part 135 operators. According to the FAA, the rationale and requirements for the NPRM were finalized and would be presented to the Regulatory Review Board in early 1987. On May 15, 1987, the Safety Board asked for an update on the status of the NPRM. On May 16, 1989, the FAA stated that the March 1989 Volpe National Transportation System Center report, titled Investigation of Controlled Flight Into Terrain (DOT-TSC-FA994-89-10), presented an investigation of CFIT accidents involving multiengine, fixed-wing, turbine-powered aircraft operating in accordance with 14 CFR Part 135 at the time of the accident and the potential application for a GPWS. The FAA stated that, as a result of the Volpe report and the availability of a GPWS at a more reasonable cost to commuter aircraft, the FAA was considering the issuance of an NPRM to address the intent of Safety Recommendation A-86-109. On June 20, 1989, the Safety Board stated that it was pleased that the FAA was considering the issuance of an NPRM.

On April 24, 1992, the FAA stated that, on March 17, 1992, it issued a final rule (Docket No. 26202; Amendment No. 135-42) to require that all turbine-powered (rather than only turbojet) airplanes with 10 or more seats be equipped with an approved GPWS. On June 10, 1992, the Safety Board stated that it was pleased to note that the FAA had issued the final rule and that, as a result, Safety Recommendation A-86-109 was classified "Closed—— Acceptable Action."

GPWS Installation for 14 CFR Part 91 Operations (A-92-55 and A-95-35)

On December 11, 1991, a Bruno's, Inc., Beechjet 400, N25BR, operating under 14 CFR Part 91, impacted mountainous terrain approximately 3 minutes after takeoff from Richard B. Russell Airport near Rome, Georgia. The two flight crewmembers and all seven passengers were killed. The airplane was not equipped with a GPWS and was not required by the FARs to be so equipped. The Safety Board concluded that, if a GPWS had been installed on the airplane, a warning would have sounded about 12 seconds before impact and would have most likely provided sufficient time for the pilots to take action to avoid flying into terrain.^[143]As a result of the accident, the Board issued Safety Recommendation A-92-55, which asked the FAA to Require all turbojet-powered airplanes that have six or more passenger seats to be equipped with a ground proximity warning system.

The FAA, however, did not agree with this recommendation. In an October 13, 1992, letter to the Safety Board, the FAA stated that, in making the determination not to require a GPWS on all turbojet-powered airplanes with six or more passenger seats, it considered, "among other factors, the operating environment most prevalent for turbojetpowered airplanes, the extent of radar service in the air traffic control system, and the employment of the minimum safe altitude warning system." On January 6, 1993, the Board classified Safety Recommendation A-92-55 "Closed--Unacceptable Action." After the June 18, 1994, TAESA Learjet accident at Dulles International Airport,^[144]</ref> the Safety Board issued Safety Recommendation A-95-35, which asked the FAA to {{|Require within 2 years that all turbojet-powered airplanes with six or more passenger seats have an operating ground proximity warning system installed.}}

On June 14, 1995, the FAA stated that it had asked the Volpe National Transportation Systems Center to study CFIT accidents involving turbojet-powered airplanes equipped with six or more passenger seats and document those CFIT accidents that would have been avoided if GPWS or enhanced GPWS had been installed.^[145] The FAA stated that it would review the results of the study to determine any regulatory action that would need to be initiated. On August 29, 1995, the Safety Board stated that it would wait for the study to be completed and then evaluate the actions taken by the FAA in response to the study's findings.

On April 17, 1997, the FAA stated that it had initiated rulemaking proposing to mandate the installation of enhanced GPWS on all turbine-powered airplanes with six or more passenger seats.^[146] The FAA also indicated that the White House Commission on Aviation Safety and Security issued a recommendation that urged the installation of enhanced GPWS on commercial aircraft. The FAA stated that it was proposing to revise 14 CFR Parts 91, 121, and 135 to address the Board's and White House's recommendations.

On July 31, 1997, the Safety Board said that it reviewed the results of the study by the Volpe National Transportation Systems Center. The Board stated that it was pleased that the FAA had initiated rulemaking activity to revise 14 CFR Parts 91, 121, and 135 to mandate enhanced GPWS on all turbine-powered airplanes with six or more passenger seats. The Board indicated that nearly 1 year had passed since the study was completed, and the Board hoped that the FAA's important rulemaking action would not be further delayed.

On January 13, 1998, the Houston Gates Learjet accident occurred. This accident, which was briefly discussed in section 1.18.1.2, involved a positioning flight operating under 14 CFR Part 91. The airplane departed from Hobby Airport in Houston for George Bush Intercontinental Airport, where five people were waiting to board the airplane for a 14 CFR Part 135 charter flight to Fargo, North Dakota. The captain and first officer--the sole occupants aboard the flight--were killed when the airplane struck trees and impacted the ground, and the airplane was destroyed by impact forces and fire. The airplane was not equipped with a GPWS and was not required by the FARs to be so equipped. Although the Safety Board determined that the probable cause of this accident was flight crew error, the Board also found that the lack of an FAA requirement for a GPWS on the airplane was a factor in the accident.

On May 12, 1999, the Safety Board stated that the circumstances of the Houston Learjet accident, the TAESA Learjet accident, and the Bruno's Beechjet accident clearly indicated the potential to reduce CFIT accidents by requiring the installation of a GPWS in turbojet-powered airplanes equipped with six or more passenger seats. The Board further stated that the 1996 DOT study provided compelling evidence that Safety Recommendation A-95-35 should be broadened to include turboprop-powered airplanes and require the installation of enhanced GPWS. As a result, the Safety Board classified Safety Recommendation A-95-35 "Closed--Acceptable Action/Superseded."^[147]

Enhanced GPWS for Transport-Category Airplanes (A-96-101)

On December 20, 1995, American Airlines flight 965, a Boeing 757, N651AA, was on a regularly scheduled 14 CFR Part 121 flight from Miami, Florida, to Cali, Colombia, when it struck trees and crashed into the side of a mountain in night VMC.^[148] Of the 8 crewmembers and 156 passengers aboard the airplane, all but 4 were killed. The airplane was equipped with a GPWS, as required. Approximately 12 seconds before impact, the GPWS began issuing aural warnings of "TERRAIN" and "PULL UP." However, the GPWS did not provide the warning in time for the flight crew to successfully avoid crashing into the mountainous terrain. As a result of this accident, the Safety Board issued Safety Recommendation A-96-101, asking the FAA to

Examine the effectiveness of the enhanced ground proximity warning equipment and, if found effective, require all transport-category aircraft to be equipped with enhanced ground proximity warning equipment that provides pilots with an early warning of terrain.

On December 31, 1996, the FAA stated that it had begun evaluating the effectiveness of enhanced GPWS. Further, the FAA stated its belief that enhanced GPWS would perform as intended and should significantly increase a pilot's situational awareness. The FAA indicated that evaluations to date revealed that enhanced GPWS would be a valuable aid in preventing CFIT accidents. The FAA anticipated completing its evaluation by March 1997 and stated that it would initiate appropriate action based on the results of the evaluation.

On April 11, 1997, the Safety Board acknowledged that the FAA was considering the issuance of an NPRM to require enhanced GPWS equipment on all civil, turbinepowered aircraft with six or more passenger seats. The Board indicated that it would wait to review the FAA's final action.

On May 4, 1999, the FAA stated that, in August 1998, it issued an NPRM proposing to require the installation and use of TAWS on any U.S.-registered turbinepowered airplane with six or more passenger seats operating under 14 CFR Parts 91, 121, and 135. According to the FAA, because operators under 14 CFR Part 125 and operators of U.S.-registered airplanes under 14 CFR Part 129 must comply with 14 CFR Part 91, they would also have to meet the proposed requirements of the NPRM. The FAA further indicated that it had issued TSO C151, "Terrain Awareness and Warning System," for public comment. According to the FAA, TSO C151 would prescribe the minimum operational performance standards that a TAWS must meet.^[149] The FAA stated that the comment period for TSO C151 was from November 4, 1998, to January 26, 1999. The FAA also stated that it had extended the ending date of the comment period for the NPRM from November 24, 1998, to January 26, 1999, to coincide with the ending date of the comment period for the TSO.

On July 13, 1999, the Safety Board stated that, pending the issuance of the final rule on the installation and use of TAWS and TSO C151, Safety Recommendation A-96-101 was classified "Open--Acceptable Response." In an October 1, 1999, response, the FAA stated that it had issued the final TSO on August 16, 1999. The FAA also stated that it expected to issue the final rule by March 2000 with an effective date of 1 year after the date of issuance.

The Safety Board's evaluation and classification of Safety Recommendation A-96-101 are discussed in section 2.8.2.

Enhanced GPWS for Turbine-Powered Airplanes (A-99-36)

As part of its investigation into the 1998 Houston Learjet accident (see the discussion regarding Safety Recommendation A-95-35), the Safety Board concluded that the 4-year TAWS installation time frame should be shortened for airplanes that lack any GPWS protection. On May 12, 1999, the Safety Board issued Safety Recommendation A-99-36, which asked the FAA to

Require, within 3 years, that all turbine-powered airplanes with six or more passenger seats that are not currently required to be equipped with a ground proximity warning system (GPWS) have an operating enhanced GPWS (or terrain awareness and warning system).

On July 26, 1999, the FAA stated that, in August 1998, it had issued an NPRM on the installation and use of TAWS on any U.S.-registered turbine-powered airplane with six or more passenger seats operating under 14 CFR Parts 91, 121, and 135. The FAA indicated that the NPRM proposed adding new rules that would prohibit the operation of certain airplanes unless those airplanes were equipped with a TAWS that met the minimum operational performance standards prescribed in TSO C151, "Terrain Awareness and Warning System."

The FAA also stated that, on May 27, 1999, it published a change to the proposed TSO to include two classes (A and B) of TAWS equipment. According to the FAA, TSO C151 Class A equipment would be required for airplanes operated under 14 CFR Part 121 and for airplanes configured with 10 or more passenger seats operating under 14 CFR Part 135, and TSO C151 Class B equipment would be the minimum requirement for airplanes operating under 14 CFR Part 91 and for airplanes configured with six to nine passenger seats operating under 14 CFR Part 135. The FAA indicated that both classes of equipment would include the TAWS features of comparing airplane position information with an on-board terrain database and providing appropriate caution and warning alerts, if necessary. Further, the FAA stated that it revised the proposed TSO to include the airworthiness requirements for both classes of equipment.

The FAA indicated that it expected to issue the final TSO by September 1999 and the final rule by March 2000, with an effective date 1 year after the date of issuance. According to the FAA, the final rule would mandate the installation of TAWS within 1 year after the effective date on new-production airplanes and within 4 years after the effective date for existing airplanes. The FAA indicated that these compliance dates, which were established in the current NPRM, were developed based on product availability and the anticipated manufacturing approval process. The FAA further indicated that a change in the compliance dates, as recommended in this safety recommendation, would require publishing a supplemental NPRM. The FAA believed that any change to the current rulemaking effort would delay the implementation of TAWS well beyond the proposed dates of the current final rule, as well as the compliance dates included in the recommendation. On October 1, 1999, the FAA stated that it had issued the TSO C151 on August 16, 1999.

The Safety Board's evaluation and classification of Safety Recommendation A-99-36 are discussed in section 2.8.2.

1.18.3 Controlled Flight Into Terrain Accident Information

1.18.3.1 Flight Safety Foundation Study of Controlled Flight Into Terrain Accidents

In the early 1990s, the Flight Safety Foundation (FSF) created a CFIT Awareness Task Force to promote general CFIT awareness. This task force evolved into an international Approach and Landing Accident Reduction Task Force, working under the auspices of the FSF. According to statistics compiled by the task force, CFIT accidents have killed more than 9,000 passengers and crewmembers since the beginning of commercial jet operations in the late 1950s. The statistics also indicate that, between 1988 and 1997, more than 2,800 people were killed in 39 CFIT-related accidents worldwide.

The FSF task force estimated that about 25 CFIT accidents occur worldwide each year involving large commercial jet transports and large commuter and regional turboprop airplanes. Several factors that frequently appeared in CFIT accident reports included night and limited visibility conditions, terrain not observed until just before impact, loss of horizontal or vertical situational awareness, unfamiliarity with terrain and obstructions, flight crew uncertainty about altitudes and distance from the airport, navigational equipment improperly set or misinterpreted by the flight crew, and an unstabilized approach.

The FSF, using statistics from the United Kingdom's CAA global database, found that 287, or 46 percent, of the 621 fatal CFIT accidents worldwide between 1980 and 1986 occurred during the approach and landing phase of flight. A study commissioned by the CAA for the FSF^[150] examined these 287 fatal approach and landing accidents.^[151] According to the study, these 287 accidents resulted in 7,185 fatalities to passengers and crewmembers, which averaged 25 fatalities per accident, or 63 percent of the total aircraft occupants.

The study indicated that 75 percent of the accidents occurred when a precision approach aid was neither available nor used and that nighttime accidents occurred at three times the rate of those that occurred during daylight conditions. The lack of ground aids was cited in at least 25 percent of the accidents. The study concluded that the "most frequent circumstantial factors were non-installation of currently available safety equipment (generally GPWS systems) and the failure to emphasize the use of crew resource management."

The study determined that, in 279 of the accidents,^[152] the 5 most frequently identified primary causal factors--omission of action/inappropriate action, lack of positional awareness in the air, flight handling, "press-on-itis," and poor professional judgment/airmanship--accounted for 71 percent of the accidents.^[153] According to the FSF, omission of action/inappropriate action generally referred to the crew continuing the descent below the DH or MDA without visual reference or when visual cues were lost. Lack of positional awareness in the air generally involved a lack of appreciation of the aircraft's proximity to high ground, frequently when the aircraft was not equipped with a GPWS and when precision approach aids were not available. Press-on-itis referred to a flight crew's "determination to get to a destination or persistence in a situation when that action is unwise." The study also determined that all five primary causal factors involved crewmembers.^[154]

The study reported that the number of accidents and the number of fatalities showed an overall increasing trend and that, if the trend were to continue, "...by 2010 there will be 23 fatal ALAs [approach and landing accidents] with a total of 495 fatalities annually involving Western-built aircraft (commercial jets, business jets and turboprop airplanes)...." On the basis of the results of this study, the FSF Approach and Landing Accident Reduction Task Force issued nine conclusions and recommended several initiatives to support each conclusion.156 (The recommendations for each conclusion^[155] are detailed in appendix C.) The conclusions were as follows:

• Establishing and adhering to adequate standard operating procedures and CRM processes will improve approach and landing safety.
• Improving communication and mutual understanding between ATC services and flight crews of each other's operational environment will improve approach and landing safety.
• Unstabilized and rushed approaches contribute to ALAs.
• Failure to recognize the need for and to execute a missed approach, when appropriate, is a major cause of ALAs.
• The risk of ALAs is higher in operations conducted during low light and poor visibility, on wet or otherwise contaminated runways, and with the presence of optical physiological illusions.
• Using the radio altimeter as an effective tool will help prevent ALAs.
• When the PIC [pilot-in-command] is the PF and the operational environment is complex, the task profile and workload reduce PF flight management efficiency and decision-making capability in approach and landing operations.
• Collection and analysis of in-flight parameters (for example, flight operations quality assurance programs) can identify performance trends that can be used to improve the quality of approach and landing operations. Global sharing of aviation information decreases the risk of ALAs.

1.18.3.2 Factors Involved in Recent Controlled Flight Into Terrain Accidents and Incidents

A British Airways Boeing 777 captain who was a member of the FSF's Approach and Landing Accident Reduction Task Force and CFIT Awareness Task Force testified at the Safety Board's public hearing about the factors that have been involved in CFIT accidents and incidents. The captain testified that five of six CFIT accidents in 1996 and 1997 occurred during nonprecision approaches. The captain also said that, from 1988 to 1997, one-half of the commercial jet CFIT accidents were during step-down approaches, even though most of those airplanes had DME available.^[156]

The captain testified that, according to the accident data, the chances of a CFIT accident occurring during a nonprecision approach is five times greater than during a precision approach. The captain also stated that nonprecision approaches are generally much more complex than precision approaches because, for many pilots, nonprecision approaches are less familiar, are more prone to error, and require more comprehensive briefing. Further, the captain stated that nonprecision approaches need particularly careful and accurate monitoring and that it is possible, with complex step-down procedures, for steps to be missed or taken out of order. The captain added, "in other words, to get one step ahead of the airplane could be fatal." He recommended eliminating step-down nonprecision approaches "...because the accident data says we should...." In addition, the captain testified that nonprecision approaches need much more carefully managed airplane crew and checklist management because many CFIT accidents occur when the crew is preoccupied or distracted by other tasks.

The captain stated that 70 percent of the CFIT accidents occurred on final approach and that most of these aircraft were "...in line with the runway." The captain also stated that "...many accident aircraft [were] underneath the three-degree glideslope [of a precision approach]." Figure 10 shows vertical profile information that was available from the 40 CFIT accidents and incidents that occurred between 1986 and 1990, as prepared by Boeing and provided by the FSF's CFIT Awareness Task Force.

Figure 10. Vertical profile information from the 40 CFIT accidents and incidents between 1986 and 1990.
Reproduction courtesy of The Boeing Company and the Flight Safety Foundation's Controlled Flight Into Terrain Awareness Task Force.

The captain stated his belief that no single measure or piece of aircraft equipment can prevent CFIT accidents and that a range of measures suited to a particular operator and operating environment is needed. The captain added that ICAO has planned a series of CFIT-related actions, including the following:

• the adoption of colored terrain and minimum safe altitude contour presentation on approach procedure charts to improve their readability and understanding by a flight crew, particularly in the cockpit environment at night;
• new requirements and new emphasis on standard operating procedures (specifically, altitude awareness procedures), including the use of standard or automated callouts, guidance on the use of autopilot, and the incorporation of stabilized approach procedures concepts;
• changes to instrument approach procedure design, including the optimum angle for nonprecision approaches and the application of vertical navigation (VNAV) or FMS during nonprecision approaches; and
• the translation of the FSF's Education and Training Aid (see section 1.18.3.3) from English into the other five languages used by ICAO.^[157]

1.18.3.3 Controlled Flight Into Terrain Training Aids

The Boeing Commercial Airplanes Group, along with the FAA, and the FSF have developed and published CFIT educational materials and training aids for use by operators. The purpose of each aid is to heighten flight crew awareness to CFIT precursors and the methods and techniques to avoid this type of accident.

The Boeing/FAA CFIT Education and Training Aid, which became available to air carriers in 1997, is presented in five sections. According to the FAA, this training aid, along with a new videotape, was distributed to all 14 CFR Part 121 and 135 operators for inclusion in their training programs. Section one provides a broad overview for airline executives of CFIT problems and possible solutions. Section two, titled "A Decision Maker's Guide," describes airline operations, aviation industry regulators, and industry efforts to eliminate CFIT. Section three, titled "An Operator's Guide," describes causal factors of CFIT accidents, the traps in which flight crews can find themselves, and specific in-flight escape maneuvers. Section four describes a model CFIT airline education program. Section five provides additional background information on CFIT and references selected reading materials and accident and incident information.

The FSF's CFIT Task Force developed a CFIT checklist in 1993 to aid in the avoidance of CFIT accidents. The checklist was designed so that the user, before a flight, could evaluate the risk factors and identify the potential for a CFIT accident. For example, the checklist indicated that flying in night IMC significantly increases the risk of a CFIT accident occurring. The checklist is divided into two diagnostic parts. The first part, titled "CFIT Risk Assessment," includes negative destination CFIT risk factors, such as VOR/DME approaches, airports near mountainous terrain, and radar coverage limited by terrain masking. Further, this assessment evaluates risk multipliers, such as IMC weather and extended crew duty days. The second part, titled "CFIT Risk Reduction Factors," includes positive company management traits and the availability of CFIT training programs.

1.18.3.4 Previous Safety Board Recommendations Related to Controlled Flight Into Terrain

Since the early 1970s, the Safety Board has issued numerous safety recommendations to the FAA in response to CFIT accidents, including those discussed as part of the GPWS and enhanced GPWS recommendations in section 1.18.2.4 and approach procedure design recommendations in section 1.18.4.4. This section provides information on other CFIT-related safety recommendations. On December 20, 1995, the American Airlines flight 965 accident near Cali, Colombia, occurred.^[158]

On October 16, 1996, the Safety Board issued Safety Recommendations A-96-93 through -95, A-96-102, and A-96-106 as a result of the findings from this accident investigation.^[159]

Safety Recommendation A-96-93 asked the FAA to

Evaluate the terrain avoidance procedures of air carriers operating transportcategory aircraft to ensure that the procedures provide for the extraction of maximum escape performance and ensure that those procedures are placed in procedural sections of the approved operations manuals.

On April 23, 1997, the FAA stated it agreed with the intent of Safety Recommendation A-96-93 and that it had completed its efforts to evaluate terrain avoidance procedures. The FAA stated that, in January 1997, it developed and published the CFIT Education and Training Aid along with Boeing (see section 1.18.3.3). The FAA also stated that, on February 25, 1997, it issued a revision (Change 2) to AC-120-51B, "Crew Resource Management," Appendix 3, "Appropriate CRM Training Topics," paragraph 2(1), to recommend that CRM training in LOFT or Special Purpose Operational Training for flight crewmembers contain a CFIT scenario. According to the FAA, this paragraph recommends that the training should emphasize prevention through effective communication and decision behavior and the importance of immediate, decisive, and correct response to a ground proximity warning.

On November 13, 1997, the Safety Board acknowledged the progress made by the FAA but noted that the FAA's response did not address whether the escape/terrain avoidance procedures would be included in the procedural sections of approved operations manuals. Pending further information from the FAA, Safety Recommendation A-96-93 was classified "Open——Acceptable Response."

On August 11, 1999, the FAA stated that it would issue a flight standards information bulletin that directed POIs to ensure that the aircraft-specific procedure for maximum escape performance (as depicted in the CFIT training aid), or an equivalent of that procedure, was contained in each appropriate FAA-approved operations manual. The FAA indicated that it planned to issue the bulletin by the end of August 1999.

On October 20, 1999, the FAA indicated that it had issued Flight Standards Information Bulletin for Air Transportation 99-08, "Controlled Flight Into Terrain (CFIT) Training," on October 5, 1999. According to the FAA, the bulletin announces the publication of the CFIT Education and Training Aid and informs POIs that the training aid is posted on the FAA's Web site. The FAA stated that the bulletin also directs POIs to ensure that the aircraft-specific procedure for maximum escape performance is contained in each appropriate FAA-approved operations manual.

Safety Recommendation A-96-94 asked the FAA to

Require that all transport-category aircraft present pilots with angle-of-attack information in a visual format and that all air carriers train their pilots to use this information to obtain maximum possible airplane climb performance.^[160]

On December 31, 1996, the FAA stated that it had begun an evaluation to assess the operational requirements for an angle-of-attack ^[161] indicator. The FAA indicated that the evaluation should be completed by March 1997.

On April 11, 1997, the Safety Board stated its understanding that the FAA's assessment would include implementation and training requirements, the complexity and cost of the system, and other functions and would indicate the angle-of-attack for maximum rate climb. The Safety Board also stated its understanding that, if angle-ofattack indicators were warranted, the FAA would take appropriate regulatory action. Pending an evaluation of the FAA's completed action, Safety Recommendation A-96-94 was classified "Open——Acceptable Response." On May 4, 1999, the FAA stated that it had evaluated the requirements for the display of angle-of-attack information to obtain the maximum airplane climb performance. The FAA indicated that angle-of-attack information during an escape maneuver could provide some improvement in climb performance but that the prevention of terrain escape maneuvers would provide much greater safety benefit than the climb performance improvements gained by the display of angle-of-attack-information.

The FAA indicated that it had reviews CFIT accidents and analyses of CFIT accident data prepeared by various organisations. The FAA stated that its review found that accdients haveonly rarely been cuased by failure to obtain the maximum possible airplane climb performance during the ground proximity escape maneuver. Thus, the FAA believed that more effective prevention of CFIT accidents would yield the greatest saftey benefit.

The FAA cited initiative to prevent CFIT accidents, including TAWS and the use of FMS with VNAV capability for constant angle of descent approaches. The FAA believed that these initatives would greatly improve pilots' situational awareness with regard to terrain and would directly reduce the likelihood that pilots using these systems would need to perform a ground proximity escape maneuver. Further, the FAA belived that the safety gains from improvements in escpae maneuver climb performance, gained by the intorductionof angle-of-attack information, would be overshadowed by the safety gains from the implementation of TAWS, especially when that system is combined with other technologies, such as FMS with VNAV capability and GPS.

Reagrding the training position of Safety Recommendation A-86-94, the FAA stated that it was revising air carrier pilot training requirements contained in 14 CFR Part 121 to include mandatory training in the ground proximity escape maneuver recommended by manufacturers for their specifc airplane(s). The FAA indicated that one objective of this training would be to improve pilot actions in achieving maximum airplane climb performance during the escape maneuver. In addition, the FAA stated that the regulatory proposal would refer to the guidance in the CFIT Education and Training Aid, which provides instructions on how to achieve the optimum angle-of-attack (given the indications available in the airplane) and the manufacturers' recommended ground proximity escape maneuvers.

Saftey Recomendation A-96-95 asked the FAA to

Develop a controlled flight into terrain training program that includes realistic simulator exercises comparable to the successful windshear and rejected takeoff training programs and make training in such a program mandatory for all pilots operating under 14 CFR Part 121.

On April 23, 1997, the FAA stated it agreed with the intent of Safety Recomendation A-96-95 and that it had completed its efforts to evaluate terrain avoidance procedures. The FAA stated that, in January 1997, it developed and published the CFIT Education and Training Aid along with Boeing. The FAA also stated that, on February 25, 1997, it issued Change 2 to AC-120-51B Appendix 3, paragraph 2(1) to recommend that CRM training in LOFT or Special Purpose Operational Training for flight crewmembers contain a CFIT scenario. According to the FAA, this paragraph recommends that the training should emphasize prevention through effective communication and decision behavior and the importance of immediate, decisive, and correct response to a ground proximity warning.

On November 13, 1997, the Safety Board acknowledged the progress made by the FAA but noted that the FAA's response did not indicate that the newly developed CFIT training program was mandatory, as urged by the recommendation. Pending further information from the FAA, Safety Recommendation A-96-95 was classified "Open-- Acceptable Response."

On August 11, 1999, the FAA stated that it had initiated an NPRM proposing to mandate training in CFIT, including flight training in simulators and the ground proximity escape maneuver. The FAA indicated that the NPRM was expected to be published in December 2000.

The Safety Board's evaluation and classification of Safety Recommendation A-96-95 are discussed in section 2.8.

Safety Recommendation A-96-102 asked the FAA to Require that all approach and navigation charts graphically present terrain information.^[162]

On December 31, 1996, the FAA stated that it agreed with the intent of this recommendation. However, the FAA stated that it was not necessary to depict terrain on IFR en route low-altitude charts because the off-route obstruction clearance altitudes adequately presented terrain and obstruction clearance information. In addition, the FAA indicated that the Government/Industry Charting Forum, chaired by the FAA's Air Traffic Service, was evaluating the possibility of adding terrain information (contour lines and shading) graphically on approach charts.

On April 11, 1997, the Safety Board stated that, although the FAA's action regarding approach charts was appropriate, the Board did not agree with the FAA that current off-route obstruction clearance altitudes adequately presented terrain and obstruction clearance information. The Board reiterated that the intent of this recommendation was to have terrain information graphically presented on all approach and navigation charts.

On February 19, 1998, the FAA stated that the Task Group 31 from the Air Cartographic Committee (a Government interagency and aviation industry committee) was evaluating the possibility of adding contour lines and shading on the plan view portion of approach charts for terrain-impacted airports only. The FAA also stated its belief that the addition of contour lines and tinting to IFR en route charts has not been supported by users and industry personnel and that sufficient information on en route charts obviates the need for such changes. Further, the FAA stated that overlaying additional information into charts that already contained a considerable amount of information could diminish the clarity of existing information on those charts.

On September 3, 1998, the Safety Board stated that the points the FAA raised with regard to adding information to en route charts were valid. However, the Board noted that these concerns did not apply to terminal navigation charts and approach charts. The Safety Board continued to believe that the FAA should do all it can to enhance pilots' situational awareness regarding proximity to terrain and that adding readily interpretable terrain information to navigation charts would be an economical way to accomplish this goal.

The Safety Board indicated that it would await FAA action regarding approach charts after the efforts of Task Group 31 were completed. Because the FAA appeared unwilling to require that terminal charts graphically portray terrain information to help prevent CFIT accidents, Safety Recommendation A-96-102 was classified "Open-- Unacceptable Response."

On July 7, 1999, the FAA stated that it met with the Safety Board on March 12, 1999, to clarify the intent of this safety recommendation and discuss the issue of adding terrain contours to all charts. At this meeting, the FAA indicated that it would consider placing terrain contours only on en route area charts. According to the FAA, this plan was proposed in April 1999 at the Government/Industry Aeronautical Charting Forum, which endorsed the proposal. The FAA stated that it was developing funding requirements with the National Oceanic and Atmospheric Administration and that, pending funding approval, it would submit a requirements document to the Interagency Air Cartographic Committee to amend the chart specifications to add terrain contours to en route area charts. The FAA also stated that it was planning to add terrain contours on instrument approach procedure charts for terrain-impacted airports.

On September 24, 1999, the Safety Board stated that, on the basis of the FAA's commitment to consider adding terrain contours to en route area charts only, Safety Recommendation A-96-102 was classified "Open——Acceptable Alternate Response."

Safety Recommendation A-96-106 asked the FAA to

Revise Advisory Circular 120-51B to include specific guidance on methods to effectively train pilots to recognize cues that indicate that they have not obtained situational awareness, and provide effective measures to obtain that awareness.

On December 31, 1996, the FAA stated that it would fund a research project to determine cues that flight crewmembers could readily recognize to indicate situational awareness problems. According to the FAA, this project would focus on developing specific cues for situational awareness in automated cockpits. The FAA indicated that, as soon as this project was completed, it would revise AC 120-51B to include guidance on training flight crews in cue recognition. On April 11, 1997, the Safety Board stated that it was waiting to evaluate the FAA's revised version of AC 120-51B.

On August 3, 1998, the FAA stated that the results of its research project were outlined in a report, titled Guidelines for Situation Awareness Training, which was published in February 1998. According to the FAA, the report included an overview, specific training tips, and sample training courses for use by the aviation community. The FAA indicated that it would incorporate guidance on cue recognition training for flight crewmembers in AC 120-51B. On November 2, 1998, the Safety Board restated that it would wait to evaluate the FAA's revised version of AC 120-51B.

On December 11, 1998, the FAA stated that, on October 30, 1998, it issued AC 120-51C, "Crew Resource Management Training," a revision to AC 120-51B. The FAA stated that Appendix 3, "Appropriate CRM Training Topics," paragraph 2(m), specifically addressed training for pilots in recognizing cues that indicate lack or loss of situational awareness in themselves and others and training in countermeasures to restore that awareness. According to the FAA, paragraph 2(m) reiterates that training should emphasize the importance of recognizing each pilot's relative experience level, experience in specific duty positions, preparation level, planning level, normal communication style and level, overload state, and fatigue state. Further, the FAA stated that training should emphasize that improper procedures, adverse weather, and abnormal or malfunctioning equipment might reduce situation awareness. In addition, the FAA stated that AC 120-51B references the Guidelines for Situation Awareness Training report because of the AC's expanded guidance on cues and countermeasures.

On March 1, 1999, the Safety Board stated that the amendments to AC 120-51B, which resulted in the issuance of AC 120-51C, met the intent of this recommendation. Accordingly, Safety Recommendation A-96-106 was classified "Closed-- Acceptable Action."

1.16.3.5 Previous Controlled Flight Into Terrain Accidents Related to Nonprecision Instrument Approach Procedures

As stated in section 1.18.3.2, accident data has shown that the chances of a CFIT accident occurring during a nonprecision approach is five times greater than during a precision approach. In addition to the CFIT events discussed previously (including the USAir flight 105 incident in Kansas City, Missouri, and the American Airlines flight 965 accident in Cali, Colombia) and in section 1.18.4.4 (American Airlines flight 1572 in East Granby, Connecticut), the Safety Board has investigated the following CFIT accidents that occurred while the airplane was on a nonprecision approach:

On February 18, 1989, a Flying Tigers Boeing 747-200, operating as a cargo flight under 14 CFR Part 121, crashed while on an NDB approach to Subang International Airport in Kuala Lumpur, Malaysia. Night visual conditions prevailed around the airport at the time of the accident. All four airplane occupants were killed, and the airplane was destroyed. The investigation into this accident was being conducted by the Department of Civil Aviation of the Government of Malaysia with the assistance of the Safety Board. On June 2, 1990, about 0937 Alaskan daylight time, Markair, Inc., flight 3087, a Boeing 737-2X6C, N670MA, operating under 14 CFR Part 121, crashed about 7 ? miles short of runway 14 at Unalakleet, Alaska, while executing a localizer-only approach in IMC. One flight attendant received serious injuries; the captain, the first officer, and a flight attendant received minor injuries; and the aircraft was destroyed. The Safety Board determined that the probable cause of the accident was deficiencies in flight crew coordination, the crew's failure to adequately prepare for and properly execute the localizer-only runway 14 nonprecision approach, and the crew's subsequent premature descent.^[163]

On April 3, 1996, a U.S. Air Force CT-43A (737-200) carrying the Secretary of Commerce, other Government officials, and a delegation of business executives crashed on a mountainside while on an NDB approach to Cilipi Airport in Croatia. All 35 people aboard the airplane were killed. The Safety Board provided technical assistance to the Air Force during its investigation.^[164]

1.18.4 Industry Actions to Improve the Safety of Nonprecision Instrument Approaches Conducted by Air Carriers

1.18.4.1 Nonprecision Approach Procedures According to the Air Line Pilots Association (ALPA),^[165] limited data indicate that airline transport crews conduct only about one to three nonprecision approaches per year and practice these approaches in a simulator "just as infrequently." Thus, ALPA concluded that the risk associated with this "inherently less safe type of approach" is compounded by the infrequency of flight crew exposure and practice. ALPA stated that most nonprecision approaches are presented in a series of step-down altitudes and that, although step-down altitudes may be satisfactory for light, slow, maneuverable aircraft, they are unacceptable for transport-category aircraft. ALPA further stated that these step-down altitudes are in fact directly contrary to the underlying concept of the stabilized approach because they require multiple power and pitch changes to be flown as charted. ALPA believed that approach charts and procedures should be modified to provide the information necessary to conduct a stabilized descent without explicit vertical guidance.

The issue of nonprecision approaches flown by air carrier (primarily turbojet) airplanes has been debated, especially in light of the recent CFIT accidents that occurred during the execution of a nonprecision approach. ALPA stated that "all turbojet air carrier airports need to have a precision approach available at all times in the appropriate landing direction." Further, ALPA believed that it is "problematic at best" for a "500,000 pound aircraft to transition from level flight (at MDA) and very high thrust settings, to a stabilized approach and touchdown in 15 to 20 seconds (the distance covered in one mile visibility at 180 knots)" because of the size of the aircraft and approach speeds at which the nonprecision approaches are flown.

1.18.4.2 Approach Chart Terrain Depiction

According to testimony at the Safety Board's public hearing by the Senior Corporate Vice President of Flight Information Technology and External Affairs for Jeppesen Sanderson, Inc., approach chart manufacturers use various methods to depict obstructions and high terrain on published approach charts. Some en route charts and the plan view of some terminal approach charts use contour lines and color shading to depict various height gradients with symbols for high obstructions. Other charts use broader colored areas for terrain depiction and specify a minimum sector altitude for obstacle clearance in segmented areas around the airport. In some instances, terrain may be depicted on the plan view of some approach charts but not on other charts published by the same manufacturer.

Currently, no chart publisher depicts terrain or obstructions on the profile view, which depicts the inbound course descent profile from the IAF to the landing or MAP. Further, the FAA Terminal Instrument Procedures (TERPS) manual contains no requirement for a standardized format that chart manufacturers must adhere to when depicting terrain on an approach chart, except for the requirement to depict the height of certain obstructions.

The Jeppesen Sanderson official testified that "the Agana ILS 6 Left approach did not have terrain [depicted on the chart]...because through the agreements that we've had with our airlines, seminars in the airline community, as well as a lot of the general aviation input, it is believed by Jeppesen that...there should be criteria because you don't want terrain to be on all charts; you want it there when it's significant." The official added that, for Jeppesen to depict terrain on a chart, there needs to be at least one elevation that is 4,000 feet or greater above the airport in at least one plan view of the airport or, if there is one elevation that is 2,000 feet above the airport within 6 miles, then contour lines need to start at the nearest 1,000 feet to the airport elevation and appear at 1,000-foot intervals all the way up to the top altitude that is depicted.

The Jeppesen official's testimony discussed the difficulties of obtaining accurate worldwide terrain data through public sources. The official said that inaccurate information was one of several reasons for not providing terrain information on the charts. The official further stated that there are many sources for terrain information but that the information needs to be publicly available so that chart manufacturers can have ready access.

The Chief Engineer of Flight Safety Systems at AlliedSignal, Inc., testified at the Safety Board public hearing about the acquisition and accuracy of terrain data. The official indicated that terrain data needs to be collected to build the database not only for chart manufacturers but also for companies that are incorporating such data into enhanced GPWS or TAWS. The official also testified that some countries still consider terrain data to be a military secret.

1.18.4.3 Federal Aviation Administration Form 8260

FAA Form 8260 provides charting companies with information for publishing instrument procedures. This form includes data for the terminal area and final and missed approach standards. The manager of the FAA's Western Flight Procedures Development Branch testified at the Safety Board's public hearing that the FAA distributes approach procedures to industry user groups (including ALPA, the Air Transport Association, and the Aircraft Owners and Pilots Association) and airport operators for comment. The manager testified that the user groups receive information that describes the approach in words or numbers and does not depict the proposed published approach. According to ALPA's submission, the information that the FAA releases "bears no resemblance to the final user product," which "seriously hampers the ability to readily and effectively critique the proposed approach procedure."

1.18.4.4 Previous Safety Board Recommendations Related to Approach Procedure Design

On November 12, 1995, American Airlines flight 1572, a McDonnell Douglas MD-83, N566AA, collided with trees in East Granby, Connecticut, while on final approach to runway 15 at Bradley International Airport in Windsor Locks, Connecticut.^[166] The airplane then landed safely at the airport. Of the 78 airplane occupants, 1 passenger received minor injuries during the emergency evacuation. The Safety Board determined that the probable cause of this accident was the flight crew's failure to maintain the required MDA until the required visual references identifiable with the runway were in sight. As a result of its investigation, the Board issued Safety Recommendations A-96-128, A-96-129, and A-96-131 through -133 on November 13, 1996.

Safety Recommendation A-96-128 asked the FAA to

Evaluate Terminal Instrument Procedures design criteria for nonprecision approaches to consider the incorporation of a constant rate or constant angle of descent to minimum descent altitude in lieu of step-down criteria.

On February 24, 1997, the FAA stated that it would begin implementation of instrument approach development proposals in late 1997. On June 26, 1997, the Safety Board stated that it was waiting to review the pending FAA proposals in response to this recommendation. On January 28, 1998, the FAA stated that it developed draft criteria to provide a constant angle of descent for aircraft with area and vertical navigation and that these criteria were incorporated into a draft order, which was being coordinated with industry. The FAA anticipated that the final order would be published in June 1998. On April 15, 1998, the Safety Board stated that it would wait to review the final order.

On August 7, 1998, the FAA stated that, on February 13, 1998, it issued a revision (Change 17) to Order 8260.3B, "United States Standard Terminal Instrument Procedures (TERPS)," which requires descent angles and descent gradients to be computed for nonprecision approaches by the FAA and subsequently depicted on aeronautical charts supplied by the National Ocean Service. The FAA indicated that the angles and descent gradients would be integrated during biennial reviews of each instrument approach procedure. According to the FAA, Change 17 states that the optimum gradient on the final approach segment is 318 feet per nautical mile, which approximates a 3° descent angle and allows VNAV-equipped aircraft to perform a stabilized descent on final approach using a computed VNAV path. Depiction of a descent gradient allows pilots to determine a target rate of descent to be maintained to fly a stabilized final approach path. Change 17 also addresses the elimination of a step-down fix through manipulation of either the FAF altitude/location or the step-down fix altitude/location. When use of the step-down fix cannot be avoided, the descent angles are provided for the portion of the final segment from the step-down fix to the runway threshold.

Additionally, the FAA stated that, on May 26, 1998, it issued Order 8260.47, "Barometric Vertical Navigation (VNAV) Instrument Procedures Development." According to the FAA, this order contains criteria for design of stand-alone area navigation approaches using barometric VNAV guidance on the final approach segment. Approaches so designed are to specify the vertical path angle from the FAF to the runway threshold. In addition, the MDA of a conventional nonprecision approach has been replaced by a decision altitude. The FAA stated that the use of a decision altitude was authorized because an allowance has been made for height loss during a missed approach and an obstacle assessment has been conducted of the visual segment (runway threshold to decision altitude point) and found to be clear of obstructions.

Because the new standards met the intent of Safety Recommendation A-96-128, it was classified "Closed——Acceptable Action" on December 8, 1998.

Safety Recommendation A-96-129 asked the FAA to

Examine and make more effective the coordinating efforts of the flight inspection program and the procedures development program, with emphasis on ensuring quality control during the development, amendment, and flight inspection process for instrument approaches.

On February 24, 1997, the FAA said that it had established a test program to ensure interaction between the flight inspection program and the procedures development program. On June 11, 1997, the FAA stated that it completed its first test program to ensure interaction between the flight inspection program and the procedures development program. According to the FAA, the test program involved the placement of a liaison position (effective March 16, 1997) in the flight inspection central operations office to respond to queries and ensure resolution of all issues. The FAA added that the individual in this position served as a focal point for the two offices to correct discrepancies found during flight, enhanced the interaction between the offices, conveyed information to flight inspection crews, and ensured standardization.

On September 8, 1997, the Safety Board stated that the actions taken to effectively coordinate the functions of the procedures development and flight inspection programs had satisfied the intent of the recommendation. Therefore, Safety Recommendation A-96-129 was classified "Closed——Acceptable Action."

Safety Recommendation A-96-131 asked the FAA to

Include a more comprehensive set of guidelines concerning precipitous terrain adjustments in the Terminal Instrument Procedures (FAA Order 8260.3B) Handbook, clarifying the definition of precipitous terrain and establishing defined criteria for addressing the potential effect of such terrain.

On January 28, 1998, the FAA stated that it was developing a plan to revise the guidelines concerning precipitous terrain adjustments currently contained in the TERPS handbook. The FAA noted that it received appropriate funding and negotiated a contract with the National Center for Atmospheric Research to develop a plan to address this recommendation. The FAA expected that it would be provided with the findings of the center's effort by the end of fiscal year 1998. On April 15, 1998, the Safety Board indicated that it would await further information from the FAA.

On June 17, 1999, the FAA stated that it was continuing its efforts to revise the guidelines concerning precipitous terrain adjustments currently contained in the TERPS Handbook. According to the FAA, the National Center for Atmospheric Research developed a prototype software package that examines digital terrain elevation data from the Defense Mapping Agency's terrain elevation database. This software uses weighted parameters to determine if the terrain underlying the primary, secondary, and buffer area approach segments are high, steep, or rough enough to be considered precipitous. The output of this software specifies the minimum adjustment to the required obstacle clearance for precipitous terrain in each segment. The FAA indicated that the TERPS Handbook would be revised to require the use of this software in identifying precipitous terrain and determining the minimum required adjustment for such terrain. On August 20, 1999, the Safety Board stated that, pending final modification of the TERPS Handbook, Safety Recommendation A-96-131 was classified "Open——Acceptable Response."

Safety Recommendation A-96-132 asked the FAA to

Review and evaluate the appropriateness of the let-down altitudes for all nonprecision approaches that have significant terrain features along the approach course between the initial approach fix and the runway. Airline safety departments and pilot labor organizations, such as the Allied Pilots Association and the Air Line Pilots Association, should be consulted as part of this review. On December 30, 1997, the FAA said that it established a mandatory review for significant terrain features as part of its biennial review process. The FAA stated that Order 8260.19C, "Flight Procedures and Airspace," section 8, includes procedures for reviews of instrument procedures, which are to be conducted every 2 years or more frequently when deemed necessary. According to the FAA, the reviews are to be conducted in accordance with Order 8260.3B, "United States Standard Terminal Instrument Procedures (TERPS)," chapter 3, "Takeoff and Landing Minimums." Paragraph 323a, "Precipitous Terrain," states that "when procedures are designed for use in areas characterized by precipitous terrain, in or outside of designated mountainous area, consideration must be given to induced altimeter errors and pilot control problems which result when winds of 20 knots or more move over such terrain." The paragraph also states that, for areas in which these conditions are known to exist, the required obstacle clearance in the final approach segment should be increased.

The FAA added that Order 8260.19C stated that user comments should be solicited to obtain the best available local information to ensure that requirements for obstacle clearance, navigational guidance, safety, and practicality were met. The FAA also indicated that, on June 2, 1997, it reemphasized the procedures to be followed when conducting a periodic review of an instrument procedure. According to the FAA, the procedures require that obstacles, including terrain, be considered as potential precipitous terrain when developing or amending a standard instrument approach procedure and that these obstacles are to be evaluated and appropriate adjustments are to be made according to existing FAA orders and guidelines. The procedures also require that discussion and coordination with the users, airline safety departments, and pilot labor organizations are included in the review process.

On April 7, 1998, the Safety Board noted that the FAA had established a mandatory review for significant terrain features as part of its biennial review process. The Board also noted that the FAA had reemphasized that these procedures be followed when conducting a periodic review of an instrument procedure. Because these actions met the intent of Safety Recommendation A-96-132, it was classified "Closed——Acceptable Action."

Safety Recommendation A-96-133 asked the FAA to

Solicit and record user comments about difficulties encountered in flying a particular approach to evaluate approach design accurately.

On February 24, 1997, the FAA stated that it would "invite airspace users to comment on dangerous approaches." On June 11, 1997, the FAA said that it had sent letters to various organizations, including the Allied Pilots Association, ALPA, the Air Transport Association, and the Aircraft Owners and Pilots Association, to request comments and concerns from their members regarding instrument flight procedures.

On September 8, 1997, the Safety Board stated that it had received copies of the letters from the industry organizations that had responded to the FAA's letter. Because the FAA's effort met the intent of Safety Recommendation A-96-133, it was classified "Closed--Acceptable Action."

1.18.5 Flight Crew Decision-making

1.18.5.1 Safety Board Study of Flight Crew Involvement in Major Accidents

In a 1994 safety study,^[167] the Safety Board examined the operating environments and errors made by flight crewmembers in 37 major accidents between 1978 and 1990. The safety issues examined in the report included the performance of flight crews when the captain was the PF, the performance of the PNF in monitoring and challenging errors made by the PF, and the adequacy of CRM training programs.

The study concluded that the captain was the PF in more than 80 percent of the 37 accidents reviewed. This result was significant because U.S. air carrier flights during the study's time frame were divided about equally between those flown by the captain and those flown by the first officer.

The Safety Board identified 302 flight crew errors in the 37 accidents; the median number of errors per accident was 7. Of the total number of errors, 232 were considered primary errors, and 70 were considered secondary errors. The primary error categories identified by the Safety Board included aircraft handling, communication, navigational, procedural (for example, not conducting or completing required checklists or not following prescribed checklist procedures), resource management, situational awareness (for example, controlling the airplane at an incorrect target altitude), systems operation, and tactical decision (for example, improper decision-making, failing to change a course of action in response to a signal to do so, or failing to heed warnings or alerts that suggest a change in the course of actions). Secondary errors resulted from the failure of a crewmember to monitor or challenge a primary error made by the other crewmember. Table 4 shows the distribution of the 302 errors identified in the 37 accidents by type of error.

The Safety Board's study determined that procedural, tactical decision, and resource management errors were largely errors of omission and that navigational and most of the aircraft handling, communication, and systems operation errors were errors of commission. Of the 232 primary errors identified, 123 (53 percent) were errors of omission, and 109 (47 percent) were errors of commission.

The safety study also determined that captains were responsible for 168 of the 302 identified errors. Of the 168 errors made by captains, 49 (29 percent) were tactical decision errors, the most common error type attributed to captains. The 49 tactical decision errors made by captains accounted for 96 percent of the 51 tactical decision errors made by all crewmembers, which is consistent with the captain's ultimate responsibility for decisions. The study also found that procedural (23 percent) and aircraft Table 4. Distribution of errors identified in the 37 accidents reviewed in the Safety Board's 1994 safety study.

Type of error	Number	Percent	Number of accidents
Primary error
Aircraft handling	46	15.2	26
Communication	13	4.3	5
Navigational	6	2.0	3
Procedural	73	24.2	29
Resource management	11	3.6	9
Situational awareness	19	6.3	12
Systems operation	13	4.3	10
Tactical decision	51	16.9	25
Secondary error
Monitoring/challenging	70	23.2	31

handling (20 percent) were the next most common error types made by captains. The aircraft handling errors made by captains accounted for 33 (72 percent) of the 46 aircraft handling errors made by all crewmembers, which is consistent with the captain conducting the PF duties on more than 80 percent of the accident flights reviewed in the study.

Further, the study stated that a common pattern in 17 of the 37 accidents was a tactical decision error by the captain (more than one-half of which constituted a failure to initiate a required action) followed by the first officer's failure to challenge the captain's decision. The study also concluded that, of the 49 tactical decision errors made by captains, 44 (90 percent) were made while the captain was serving as the PF and that 26 (59 percent) of these errors were errors of omission. Thus, the most common tactical decision error was the failure of a captain serving as the PF to take action when the situation demanded change. In addition, of the 26 tactical decision errors made by captains that were errors of omission, 16 (62 percent) involved the captain's failure to execute a goaround during the approach. These 16 errors were made during 10 different accident sequences. Of the 16 failures to execute a go-around, 8 involved an unstabilized approach.

The study found that the 70 monitoring/challenging errors committed by flight crewmembers occurred in 31 (84 percent) of the 37 accidents reviewed in the study and that most of these errors played very important roles in the accidents. The study concluded that the highest percentage of the unmonitored/unchallenged errors were tactical decision errors (40 percent).

In addition, the study found that, of the 15 accidents for which information was available, 11 (73 percent) occurred during the first duty day together for the captain and first officer. Of the 16 accidents for which data were available, 7 (44 percent) occurred during the crewmembers' first flight together. According to the study, these rates are substantially higher than the percentage of crews who would be expected to be paired for the first time on any given flight or day.

Finally, the study examined the effect of the length of time since awakening (TSA) on the errors committed by flight crewmembers in the accident sequence. The performances of flight crews in which both the captain and the first officer had been awake a long time (average TSA length, 13.6 hours) were compared with flight crews in which both the captain and the first officer had been awake a short time (average TSA length, 5.3 hours). The Safety Board found that both the number and type of errors made by the flight crews varied significantly according to the TSA length. Specifically, high TSA crews made an average of 40 percent more errors (almost all of which were errors of omission) than low TSA crews.

High TSA crews made significantly more procedural errors and tactical decision errors than low TSA crews. These results suggested that the degraded performance by high TSA crews tended to involve ineffective decision-making (such as failing to perform a missed approach) and procedural slips (such as not making altitude awareness callouts) rather than a deterioration of aircraft handling skill. Also, the number and types of errors made by the flight crews varied according to the TSA length before the accident. The median TSA periods were quite high: 12 hours for captains and 11 hours for first officers. Those pilots who had been awake longer than the median TSA length for their crew position made more decision-making errors and procedural errors than pilots who had been awake for less time.^[168]

1.18.5.2 Previous Safety Recommendations on Flight Crew Decision-making

On the basis of the findings of its safety study, the Safety Board issued Safety Recommendations A-94-3 and A-94-4 on February 3, 1994. Safety Recommendation A-94-3 asked the FAA to

Require U.S. air carriers operating under 14 CFR Part 121 to provide, for flight crews not covered by the Advanced Qualification Program, line operational simulation training during each initial or upgrade qualification into the flight engineer, first officer, and captain position that (1) allows flight crews to practice, under realistic conditions, nonflying pilot functions, including monitoring and challenging errors made by other crewmembers; (2) attunes flight crews to the hazards of tactical decision errors that are errors of omission, especially when those errors are not challenged; and (3) includes practice in monitoring and challenging errors during taxi operations, specifically with respect to minimizing procedural errors involving inadequately performed checklists.

On April 26, 1994, the FAA stated that it was amending AC 120-51A, "Crew Resource Management," to emphasize the areas detailed in the recommendation. On July 6, 1994, the Safety Board noted that including the recommendation's material in an AC would be an acceptable alternative to regulatory change. However, on May 8, 1995, the Safety Board expressed disappointment that the revised AC 120-51B (issued on January 3, 1995) made no specific reference to practicing PNF procedures, such as monitoring and challenging the errors of the other pilots, during line-oriented simulation training. Likewise, the AC contained no specific references to line-oriented simulation training in the areas of monitoring and challenging tactical decision errors or inadequately performed taxi checklist procedures.

On September 8, 1995, the FAA issued a revision (Change 2) to AC 120-51B. On January 16, 1996, the Safety Board stated that the revised AC's reference to line operational simulation was responsive to all aspects of Safety Recommendation A-94-3. The provisions for PNF functions, monitoring and challenging of errors made by other crewmembers, tactical decision errors that are errors of omission, and errors made during taxi operations would achieve the Board's objectives as an alternative to the regulatory change that was originally proposed. Therefore, Safety Recommendation A-94-3 was classified "Closed——Acceptable Alternate Action."

Safety Recommendation A-94-4 asked the FAA to

Require that U.S. air carriers operating under 14 CFR Part 121 structure their initial operating experience programs to include (1) training for check airmen in enhancing the monitoring and challenging functions of captains and first officers; (2) sufficient experience for new first officers in performing the nonflying pilot role to establish a positive attitude toward monitoring and challenging errors made by the flying pilot; and (3) experience (during initial operating experience and annual line checks) for captains in giving and receiving challenges of errors.

On April 26, 1994, the FAA stated that its actions in response to Safety Recommendation A-94-3 addressed the issues referenced in this recommendation. On July 6, 1994, the Safety Board reiterated that one intent of Safety Recommendation A-94-4 was for air carriers to provide crewmembers undergoing initial operational experience (IOE) with experience specifically in the PNF role. The Safety Board believed that the FAA should, at the very least, provide guidance to air carriers on this issue in the form of an AC.

On February 28, 1995, the FAA informed the Safety Board that, on January 3, 1995, AC 120-51B, "Crew Resource Management," was issued to provide emphasis for the PNF to monitor and challenge errors and for the PF to give and receive challenges of errors. On April 24, 1995, the Safety Board expressed its disappointment that AC 120-51B made no reference to the structure of IOE, PNF experience in monitoring and challenging errors during IOE and LOFT, or experience for captains in giving and receiving challenges of errors.

On June 16, 1995, the FAA stated that, on April 21, 1995, it had issued a final rule to amend the pilot qualification requirements for air carrier and commercial operators. According to the FAA, the final rule requires that second-in-command pilots obtain operating experience while performing the duties of a second-in-command under the supervision of a qualified pilot check airman. Additionally, the FAA stated that it was revising AC 120-51B to provide emphasis on the role of the PNF in monitoring and challenging errors and for captains to gain experience in giving and receiving challenges of errors. The FAA indicated that the revisions to the AC would emphasize the training of check airmen so that they would be prepared to enhance the monitoring and challenging functions of captains and first officers.

On August 29, 1995, the Safety Board stated that it was pleased that the FAA had issued a final rule that required air carriers to provide newly qualified second-in-command pilots with IOE while actually performing the duties of, rather than while observing, a second-in-command pilot. The Board was also pleased that the FAA was revising AC-120-51B. The Board believed that check airmen who receive training in enhancing the monitoring and challenging functions of captains and first officers would be able to provide more effective operating experience for newly qualified pilots if air carrier IOE programs ensured that pilots receive sufficient experience performing PNF functions while under check airman supervision.

On November 17, 1995, the FAA informed the Safety Board that it had revised AC-120B. On January 16, 1996, the Safety Board stated that the revised AC's reference to training for check airmen in methods that could be used to enhance the monitoring and challenging function of captains and first officers was responsive to Safety Recommendation A-94-4 because the check airmen would apply their CRM skills during IOE for new captains and first officers. Because the FAA's revisions to AC 120-51B satisfied the intent of Safety Recommendation A-94-4, it was classified "Closed——Acceptable Alternate Action."

1.18.5.3 National Aeronautics and Space Administration's Flight Crew Decision-making Study

Researchers at the National Aeronautics and Space Administration's (NASA) Ames Research Center conducted a study that examined the Safety Board's findings in its 1994 safety study (see section 1.18.5.1). The purpose of the NASA study was to analyze the accident data to identify any contributing factors such as "ambiguous dynamic conditions and organizational and socially-induced goal conflicts."^[169] The NASA researchers reexamined the 37 accidents included in the safety study to determine the most common decision errors and any themes or patterns in the context within which the errors occurred. NASA found that the most common decision errors occurred when the flight crew decided to "continue with the original plan of action in the face of cues that suggested changing the course of action." The NASA study stated:

Clearly, more cognitive effort is needed to revise one's understanding of a situation or to consider a new course of action than sticking with the original plan whose details have already been worked out.... It appears that evidence must be unambiguous and of sufficient weight to prompt a change of plan.

With regard to ambiguity and its effect on situation assessment and decisionmaking, the NASA study stated:

Cues that signal a problem are not always clear-cut. Conditions can deteriorate gradually, and the decision maker's situation assessment may not keep pace...a recurring problem is that pilots are not likely to question their interpretation of a situation even if it is in error. Ambiguous cues may permit multiple interpretations. If this ambiguity is not recognized, the crew may be confident that they have correctly interpreted the problem. Even if the ambiguity is recognized, a substantial weight of evidence may be needed to change the plan being executed.

The study noted that stress may limit the pilot's ability to properly evaluate the situation: Reaching decision...requires projection and evaluation of the consequences of the various options. If pilots are under stress, they may not do the required evaluations.... Under stress, decision makers often fall back on their most familiar responses, which may not be appropriate to the current situation.

Further, the NASA study determined that organizational and social pressures may contribute to the high incidence of "plan continuation errors" by creating goal conflicts, which may result in decision errors in the face of ambiguous cues and high-risk situations. The study noted that organizational and social factors that have the potential to create goal conflicts with safety include pressure for on-time arrival rates, fuel economy, and avoidance of diversions to reduce passenger inconvenience.

The NASA study concluded that, to reduce pressures on pilots, operators "must be willing to stand behind their pilots who take a safe course of action rather than a riskier one, even if there is a cost associated." The study noted that integrated flight displays that present up-to-date information on dynamic variables, such as weather and traffic, could reduce the ambiguity of events flight crews might encounter and that training to help flight crews develop "strategies for choosing a course of action" would be beneficial. 1.18.6 Previous Fatigue-Related Accidents

The Safety Board has investigated several accidents in which fatigue was either the cause or a contributing factor. A discussion of two such accidents follows.

Continental Express Jet Link Flight 2733

On April 29, 1993, Continental Airlines (d.b.a. Continental Express) Jet Link flight 2733, an Embraer EMB-120RT, N24706, crashed at Pine Bluff, Arkansas, during a forced landing and runway overrun at a closed airport.^[170] The flight was a scheduled 14 CFR 135 operation from Little Rock, Arkansas, to Houston, Texas. The 2 flight crewmembers and 15 passengers were uninjured, and the flight attendant and 12 passengers received minor injuries. The accident occurred on the third day of a 3-day trip sequence, and the accident flight was the seventh and last flight of the day.

As the airplane was climbing, the captain, who was the PF, increased pitch so that the flight attendant could begin cabin service. The autoflight was set in pitch and heading modes, contrary to company policy. The airplane stalled in IMC at 17,400 feet. Initial recovery was at 6,700 feet. Because of an improper recovery procedure, a second stall occurred, and recovery was at 5,500 feet. The left propeller shed three blades, the left engine cowling separated, and the left engine was shut down in descent. Level flight could not be maintained, and a forced landing was made. The captain overshot the final turn because of controllability problems, and the airplane landed fast with 1,880 feet of wet runway remaining. The airplane hydroplaned off the runway and received additional damage. No preaccident malfunction was found.

The Safety Board's review of the captain's schedule revealed that the first day of the trip involved 9.5 hours of duty time followed by 8.5 hours of rest time (a reduced rest period). The second day of the trip involved 3.8 hours of duty time. The captain was off duty at 1130 but did not go to sleep until between midnight and 0030.^[171] On the third day of the trip, the captain awoke about 0500 for an early duty time. At the time of the accident, the captain had been awake for about 11 hours.

The first officer's flight, duty, and crew rest schedules were the same as that of the captain for the 3-day trip sequence. The first officer went to bed between 2300 and midnight on the night before the accident and awoke about 0430 on the day of the accident. The first officer had also been awake about 11 hours at the time of the accident.

The Safety Board determined that the probable cause of the accident was the captain's failure to maintain professional cockpit discipline, his consequent inattention to flight instruments and ice accretion, and his selection of an improper autoflight vertical mode, all of which led to an aerodynamic stall, loss of control, and a forced landing. A factor contributing to the accident was fatigue induced by the flight crew's failure to properly manage provided rest periods.^[172]

American International Airways Flight 808

On August 18, 1993, American International Airways (d.b.a. Connie Kalitta Services, Inc.) flight 808, a Douglas DC-8-61, N814CK, was on a nonscheduled 14 CFR Part 121 operation when it crashed in at the U.S. Naval Air Station at Guantanamo Bay, Cuba.^[173] The cargo airplane collided with level terrain approximately ¼ mile from the approach end of runway 10 at Leeward Point Airfield after the captain lost control of the airplane. The airplane was destroyed by impact forces and a postcrash fire, and the three flight crew members--the only occupants aboard the airplane--received serious injuries. The cargo airplane was on the last leg of a flight sequence that day from Atlanta, Georgia, to Norfolk, Virginia, and then Guantanamo Bay.

The flight crew had been on duty about 18 hours and had flown approximately 9 hours.^[174] The captain did not recognize deteriorating flightpath and airspeed conditions because of his preoccupation with locating a strobe light^[175] on the ground. The flight engineer made repeated callouts regarding slow airspeed conditions. The captain initiated a turn on final approach at an airspeed below the calculated approach speed of 147 knots and less than 1,000 feet from the shoreline, and the captain allowed bank angles in excess of 50? to develop. The stall warning stickshaker activated 7 seconds before impact and 5 seconds before the airplane reached stall speed. No evidence indicated that the captain attempted to take proper corrective action at the onset of the stickshaker. The Safety Board concluded that the substandard performance by this experienced pilot may have reflected the debilitating influences of fatigue. In its report on this accident, the Safety Board stated that three background factors are commonly examined for evidence related to fatigue: cumulative sleep loss, continuous hours of wakefulness, and time of day. The flight crew had received limited sleep in the 48 hours before the accident because of flight and duty time. Also, at the time of the accident, the captain had been awake for 23.5 hours, the first officer for 19 hours, and the flight engineer for 21 hours. In addition, the accident occurred about 1656 eastern daylight time (based on a 24-hour clock), at the end of one of the two low periods in a person's circadian rhythm. The Board also considered the captain's self-report (for example, his report of feeling "lethargic and indifferent" in the last period before the accident) in evaluating whether fatigue was present.

The Safety Board determined that the probable cause of the accident was the impaired judgment, decision-making, and flying abilities of the captain and the other flight crewmembers because of the effects of fatigue; the captain's failure to properly assess the conditions for landing and maintaining vigilant situational awareness of the airplane while maneuvering onto final approach; his failure to prevent the loss of airspeed and avoid a stall while in the steep bank turn; and his failure to execute immediate action to recover from a stall. Additional factors contributing to the cause of the accident included the inadequacy of the flight and duty time regulations applied to 14 CFR Part 121 supplemental air carriers, international operations, and the circumstances that resulted in the extended flight and duty hours and fatigue of the flight crewmembers.

1.18.6.1 Previous Safety Recommendations Regarding Fatigue

On May 17, 1999, the Safety Board adopted a safety report entitled Evaluation of U.S. Department of Transportation Efforts in the 1990s to Address Operator Fatigue.^[176] In its report, the Board noted that in 1989 it issued three recommendations to the DOT addressing needed research, education, and revisions to hours-of-service regulations.^[177]The Board further noted that, since that time, it had issued more than 70 additional recommendations aimed at reducing the incidence of fatigue-related accidents.The Board stated that, even though the DOT and modal administrations had responded positively to the recommendations addressing research and education, little action had occurred with respect to revising the hours-of-service regulations.

The safety report discussed the activities and efforts by the DOT and the modal administrations to address operator fatigue and the resulting progress that has been made over the past 10 years to implement the actions called for in the Safety Board's fatiguerelated recommendations. The report also provided background information on current hours-of-service regulations, fatigue, and the effects of fatigue on transportation safety. As a result of its findings, the Safety Board issued Safety Recommendations I-99-1 and A-99-45.

Safety Recommendation I-99-1 asked the DOT to

Require the modal administrations to modify the appropriate Codes of Federal Regulations to establish scientifically based hours-of-service regulations that set limits on hours of service, provide predictable work and rest schedules, and consider circadian rhythms and human sleep and rest requirements. Seek Congressional authority, if necessary, for the modal administrations to establish these regulations.^[178]

Safety Recommendation A-99-45 asked the FAA to

Establish within 2 years scientifically based hours-of-service regulations that set limits on hours of service, provide predictable work and rest schedules, and consider circadian rhythms and human sleep and rest requirements.

On July 15, 1999, the FAA indicated that it agreed with the intent of Safety Recommendation A-99-45 and stated that, on December 11, 1998, it had issued NPRM 95-18, which proposed amending existing regulations to establish one set of duty period limitations, flight time limitations, and rest requirements for flight crewmembers engaged in air transportation. The FAA stated that the NPRM considered scientific data from studies conducted by NASA relating to flight crewmember duty periods, flight times, and rest and that Safety Recommendation A-99-45 would be included in this rulemaking project. The FAA further indicated that its Aviation Rulemaking Advisory Committee was tasked to review reserve issues related to the NPRM but was unable to agree on a recommendation. The FAA indicated that it was conducting a risk assessment to determine the probability of preventing future incidents related to fatigue and did not know when a supplemental NPRM would be issued. However, the FAA stated that, in the interim, it published a notice on June 15, 1999, indicating its intent to enforce the regulations concerning flight time limitations and rest requirements. At an October 7, 1999, meeting with the Safety Board's Chairman, the FAA Administrator indicated that a final rule would not be issued within the next 2 years.

1.18.7 Flight Data Recorder Documentation

A digital flight data recorder (DFDR) records values for parameters related to the operation of an airplane (for example, altitude, airspeed, and heading). The values are recorded in a serial binary digital data stream that must be converted either to engineering units or discrete states. The arrangement of the recorded values often varies among DFDR systems; consequently, accurate conversion of the recorded values to their corresponding engineering units or discrete states can be accomplished only when the configuration of the data has been thoroughly documented.

1.18.7.1 Previous Safety Board Recommendations on Flight Data Recorder Parameter Verification and Documentation

In the early 1970s, the Safety Board began issuing safety recommendations to improve FDR parameter verification and documentation. In 1991, the Safety Board issued two safety recommendations (A-91-23 and -24) to the FAA for developing a permanent policy for FDR maintenance and record-keeping. In 1997, after a series of accidents that involved problems with extracting data from retrofitted FDRs, the Safety Board issued a safety recommendation (A-97-30) that asked the FAA to publish an AC addressing the certification and maintenance of FDRs.^[179]

Safety Recommendation A-91-23 asked the FAA to

{{Smaller|Issue permanent policy and guidance material for the continued airworthiness of digital flight data recorder systems, stating that the make and model of the flight data recorder and the make and model of the flight data acquisition unit, if installed, must be maintained as part of each aircraft's records, as well as at least the following information for each parameter recorded:

• Location of parameter word (2 through 64 or 128). * Assigned bits (1 through 12).
• Range (in engineering units when applicable).
• Sign convention (for example, trailing edge up = +). * Type sensor (for example, synchro or low-level DC). * Accuracy limits (sensor input).
• FAA requirement (that is, mandatory or not mandatory).
• Subframe/superframe assignment: Documentation for engineering unit conversion.
• General equation: Provide A0, A1, A2, and A3 for the equation Y = A0 + A1X + A2X2 + A3X3, where Y = output in engineering units and X = input in decimal or converted counts.
• Nonlinear parameters: Provide a sufficient number of data samples (engineering units versus recorded decimal counts) to develop a conversion algorithm that will accurately define the full range of the parameter.
• Discrete parameters: Status (that is, 1 = on, 0 = off).

Safety Recommendation A-91-24 asked the FAA to

Require operators to maintain current information for each unique digital flight data recorder configuration in its inventory using a single, universally adopted format, such as that described in the standard being developed by Aeronautical Radio, Inc. On May 9, 1991, the FAA stated that it was reviewing these safety recommendations. On August 1, 1991, the Safety Board stated that it was disappointed that the FAA failed to include any timetable for the completion of the review because untimely or missing DFDR documentation was adversely affecting ongoing investigations. The Board reemphasized its commitment to these recommendations, stating that it would continue to work with the FAA and the aviation industry to implement the recommendations.

On December 18, 1991, the FAA stated that it was planning to develop an AC to address the installation and maintenance of DFDRs and flight data acquisition units (FDAU). The FAA indicated that the AC would reference the appropriate regulatory requirements and contain the universal documentation format for each DFDR aircraft configuration and installation. The FAA further indicated that the baseline documents for the AC would be the universal format being developed by Aeronautical Radio, Inc., and the Board's proposed FDR configuration documentation standard.

On January 28, 1992, the Safety Board stated that it remained encouraged by the FAA's support for these safety recommendations. The Board believed that the FAA's plan to develop an AC that addresses the installation and maintenance of DFDR systems and references a universal documentation standard was a step in the right direction. However, the Board believed that the AC needed to be supplemented with permanent policy and guidance material so that FAA inspectors would require that the AC be implemented.

On April 22, 1994, the Safety Board stated that, in early 1993, FAA staff had indicated that the proposed AC had not been developed because the FAA was waiting for Aeronautical Radio, Inc., to publish the proposed documentation standard. Because Aeronautical Radio was unable to commit the resources needed to publish the proposed standard, the FAA proposed that the Board draft an AC that incorporated the draft Aeronautical Radio documentation standard. Safety Board and FAA staffs subsequently discussed and agreed on the principal elements of a draft AC based on the draft Aeronautical Radio documentation standards. On October 18, 1993, the Board provided a draft of the AC and DFDR documentation standards. However, the FAA made no progress toward implementing Safety Recommendations A-91-23 and -24, even with the Board's draft AC. The Safety Board continued to believe that the actions requested in these recommendations were essential and therefore urged the FAA to take the necessary actions.

On March 3, 1997, the FAA stated that it included information regarding the installation and maintenance of DFDRs and FDAUs in Notice N8110.65, "Policy and Guidance for the Certification and Continued Airworthiness of Digital Flight Data Recorder Systems." According to the FAA, the notice referenced the appropriate regulatory requirements and contained the universal documentation format for each DFDR aircraft configuration and installation. The FAA stated that the universal format developed by Aeronautical Radio, Inc., and the Board's proposed FDR configuration documentation standard were used as baseline documents for the notice.

On July 10, 1998, the Safety Board noted its disappointment that the AC had still not been completed. The Board stated that inclusion of guidance relating to FDR maintenance documentation (which was addressed in FAA Notice N8110.65) in this AC would satisfy the intent of Safety Recommendations A-91-23 and -24, which had been issued 7 years earlier. The Board was concerned that the AC might still not be produced in a timely manner. Accordingly, the Safety Board classified Safety Recommendations A-91-23 and -24 "Open——Unacceptable Response" pending the FAA's completion of the AC.

Safety Recommendation A-97-30 asked the FAA to

Complete the planned flight data recorder (FDR) advisory circular (AC) to define FDR certification requirements and FDR maintenance requirements, and incorporate the FDR documentation standards contained in Notice N8110.65. The AC should be released no later than January 16, 1998.

On July 14, 1997, the FAA stated that it agreed with the intent of this safety recommendation. The FAA also stated that it would complete the AC for FDR certification and maintenance requirements by January 1998. On July 10, 1998, the Safety Board stated its disappointment that the AC, promised by the FAA to be issued by January 1998, had not been completed. The Board was concerned that the AC would not be produced in a timely manner. The Board stated that the guidance contained in this AC was essential to avoid widespread retrofit problems.^[180] Pending the FAA's completion of the AC, the Safety Board classified Safety Recommendation A-97-30 "Open--Unacceptable Response."

1.18.7.1.1 Digital Flight Data Recorder Advisory Circular

On October 5, 1999, AC 20-141, "Airworthiness and Operational Approval of Digital Flight Data Recorder Systems," was issued. The purpose of the AC is to provide "guidance on design, installation, and continued airworthiness of Digital Flight Data Recorder Systems." Appendix 1 to the AC, titled "Standard Data Format for Digital Flight Data Recorder Data Stream Format and Correlation Documentation," provides "a standard for the data stream format and correlation documentation that operators must maintain to aid accident investigators in interpreting recorded flight data." The appendix details how to develop a document for each airplane that would provide in detail the information that would assist Safety Board investigators in transcribing each parameter recorded by an FDR.

1.18.7.2 International Guidance Regarding the Documentation of Flight Data Recorder Parameters

ICAO provides guidance to Member States regarding the documentation of FDR parameters. ICAO Annex 6, "International Standards and Recommended Practices-- Operation of Aircraft, Part I--International Commercial Air Transport--Aeroplanes," includes Attachment D, Flight Recorders. Section 3 of the attachment, "Inspections of flight data and cockpit voice recorder systems," provides guidance on the continued airworthiness of FDR systems, including how to conduct annual checks of every FDR parameter. Paragraph 3.2(c) states that "a complete flight from the FDR should be examined in engineering units to evaluate the validity of all recorded parameters." In addition, paragraph 3.2(d) states that "the readout facility should have the necessary software to accurately convert the recorded values to engineering units and to determine the status of discrete signals."

1.18.8 Special Airport Criteria and Designation

On October 19, 1996, Delta Air Lines flight 554, a McDonnell Douglas MD-88, N914DL, struck the approach light structure at the end of the runway deck during the approach to land on runway 13 at LaGuardia Airport in Flushing, New York.^[181] IMC conditions prevailed for the ILS DME approach. None of the two flight crewmembers and three flight attendants were injured, but 3 of the 58 passengers received minor injuries. The airplane sustained substantial damage.

According to the first officer of the flight, the approach to runway 13 requires landing over water, a 250-foot DH, and an offset localizer, and the approach to the opposite direction runway (31) requires maneuvering an airplane at high bank angles close to the ground. However, LaGuardia was not designated by the FAA as a special airport under 14 CFR Section 121.445.^[182] That section, titled "Pilot in command airport qualification: Special areas and airports," states the following:^[183]

(a) The [FAA] Administrator may determine that certain airports (due to items such as surrounding terrain, obstructions, or complex approach or departure procedures) are special airports requiring special airport qualifications and that certain areas or routes, or both, require a special type of navigation qualification. (b) ...no certificate holder may use any person, nor may any person serve, as pilot in command to or from an airport determined to require special airport qualifications unless, within the preceding 12 calendar months: (1) The pilot in command or second in command has made an entry to that airport (including a takeoff and landing) while serving as a pilot flight crewmember; or (2) The pilot in command has qualified by using pictorial means acceptable to the Administrator for that airport.

The Safety Board's investigation of the accident concluded, among other things, that the FAA's guidance on special airports was not sufficiently specific about criteria and procedures for designation of special airports; therefore, the FAA's guidance might not always be useful to air carriers operating in and out of special airports. The Board also concluded that the requirements for special airport pilot qualifications might not be sufficient to ensure that qualified pilots have been exposed to the runways and/or approaches that make those airports "special."

As a result of its findings, the Safety Board issued Safety Recommendations A-97-92 through -94 on August 25, 1997. Safety Recommendations A-97-92 through -94 asked the FAA to

Expedite the development and publication of specific criteria and conditions for the classification of special airports; the resultant publication should include specific remarks detailing the reason(s) an airport is determined to be a special airport and procedures for adding and removing airports from special airport classification.(A-97-92)

Develop criteria for special runways and/or special approaches, giving consideration to the circumstances of this accident and any unique characteristics and special conditions at airports...and include detailed pilot qualification requirements for designated special runways or approaches.(A-97-93)

Once criteria for designating special airports and special runways and/or special approaches have been developed, as recommended in Safety Recommendations A-97-92 and -93, evaluate all airports against that criteria and update special airport publications accordingly. (A-97-94)

On November 13, 1997, the FAA stated that it was developing a flight standards handbook bulletin and revising AC 121.445. "Pilot-In-Command Qualifications for Special Area/Routes and Airports, Federal Aviation Regulations (FAR) Section 121.445."^[184] The FAA indicated that the bulletin and AC would address the issues discussed in the recommendations. The FAA anticipated that these documents would be issued in April 1998. On August 17, 1998, the Safety Board stated that, pending the FAA's completion of these documents, Safety Recommendations A-97-92 through -94 were classified "Open--Acceptable Response."

On September 21, 1999, the FAA stated that AC 121.445 was undergoing internal coordination and should be published in the Federal Register by November 1999. The FAA indicated that it would proceed with issuing the flight standards handbook bulletin as soon as the AC was completed. According to the FAA, both documents were expected to be issued by February 2000.

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1. Unless otherwise indicated, all times are Guam local time, based on a 24-hour clock.
2. The island of Guam is a U.S. territory in the Pacific Ocean and is part of the Mariana Islands. Guam has an elected governor and a 21-member unicameral legislature. U.S. Naval and Air Force installations make up 35 percent of the island's area.
3. Six of the passengers were Korean Air flight attendants who were "deadheading," that is, traveling off duty.
4. Three passengers (including one deadheading flight attendant) initially survived the accident with serious injuries but died within 30 days after the accident. According to 14 Code of Federal Regulations (CFR) Section 830.2, such fatalities are to be included in the total number of fatal injuries. A passenger with serious injuries died at the U.S. Army Medical Center in San Antonio, Texas, on October 10, 1997, but is not officially listed as a fatality because the passenger's death occurred more than 30 days after the accident.
5. See table 1 in section 1.2 for the injury chart.
6. The captain began a scheduled round trip to Hong Kong on August 3, 1997, but his return flight was delayed because of inclement weather. As a result, the captain had to remain overnight in Hong Kong and fly back to Seoul (as a pilot) on the morning of August 4.
7. The self- and SOF briefings are required parts of Korean Air's flight crew predeparture procedures. See section 1.17.3 for additional information.
8. VOR/DME stands for very high frequency omnidirectional radio range/distance measuring equipment. DME is expressed in miles.
9. Appendix B contains the CVR transcript. The transcript expresses the times of the CVR comments and sounds in coordinated universal time (UTC). Guam local time is 10 hours ahead of UTC time.
10. The ILS is a precision approach system that provides lateral guidance (localizer) and vertical alignment (glideslope) with the runway. The system uses ground-based radio transmitters that provide both the localizer and the glideslope signals. See sections 1.6.2.3 and 1.10.2 for additional information.
11. TOD is the departing cruise altitude.
12. The FLAKE intersection is 7 DME from the NIMITZ VOR and is on the 242° radial. An intersection can be defined by the crossing of two radials or by a specific distance on a bearing from a navigational aid. An ILS approach can either be flown as a "full ILS" precision approach or a localizer-only, nonprecision approach. The criteria for both approaches are often presented on the same chart. For information on how the accident flight crew was to execute the nonprecision, localizer-only approach for runway 6L, see section 1.10.3.1.
13. The accident flight was scheduled to remain on the ground at Guam for 3½ hours and then return to Seoul at 0930 (0830 Seoul local time).
14. In the aviation industry, a "747 classic" refers to the -100, -200, -300, and -SP (special purpose) models of the Boeing 747 airplane. Classic 747s have three crewmember seats and mostly analog (mechanical) gauges.
15. ATIS information Uniform noted the Notice to Airmen (NOTAM) for runway 6L, which stated that the ILS glideslope was "out of service until further notice." See section 1.7.1.
16. The CERAP controller did not advise the flight crew of its position. FAA Order 7110.65, "Arrival Instructions," section 5-9-4, paragraph (a) states that a controller is to provide the flight crew with a "position relative to a fix on the final approach course. If none is portrayed on the radar display or if none is prescribed in the procedure, issue position information relative to the navigation aid which provides final approach guidance or relative to the airport."
17. The altitude alert system provides visual and aural signals when approaching or deviating from the selected altitude. See section 1.6.2.1 for more information.
18. A GPWS is designed to provide the flight crew with visual and aural warnings when proximity to terrain, closure rate, descent rate, bank angle, and glideslope deviation become excessive. For more information, see sections 1.6.2.2 and 1.18.2.
19. According to FAA radar data and CVR information, the captain's call for the windshield wipers to be activated occurred when the airplane was in the vicinity of the outer marker, which was located 1.6 DME from the NIMITZ VOR.
20. This alert occurs when the GPWS computer determines that the barometric sink rate of the airplane, beginning at 2,450 feet above ground level (agl), exceeds the designed threshold sink rate value. The threshold value for approximately 200 feet agl is 1,200 feet per minute.
21. The Korean MOCT is similar in function to the U.S. Department of Transportation (DOT). The Korean Civil Aviation Bureau (KCAB), a division within the MOCT, is responsible for overseeing the Korean civil airlines. For more information on the KCAB, see section 1.17.6.1.
22. For information on Korean Air's airport familiarization video presentation program, see section 1.17.3.2.
23. The first officer from the July 4, 1997, trip to Guam also indicated that the captain had used the ground time between that flight and the return trip to sleep in a seat in the first class compartment.
24. Korean Air's Level 3 Pilot English Test comprises written, listening, and oral sections. An ATCrelated part in the listening section "tests correct understanding and proper usage of ATC transmissions, ATIS broadcasts, [and] ATC terminology/phraseology." All Korean Air pilots are required to pass this test.
25. The times in sections 1.5.1 through 1.5.3 are expressed in Seoul local time, based on a 24-hour clock.
26. For information on the CERAP facility, see section 1.10.1.1.
27. For information on the Agana tower facility, see section 1.10.1.3.
28. A cycle is one complete takeoff and landing sequence.
29. For general information on GPWS, see section 1.18.2.1. For information on previous safety recommendations on GPWS and related systems, see section 1.18.2.4.
30. Desensitizing changes the range of values to which the alerts respond to minimize nuisance warnings. Desensitizing does not suppress or cancel (inhibit) the alerts. A terrain closure rate must exceed 2,500 feet per minute to initiate a warning during the time that the terrain and pull up warnings are desensitized.
31. According to the Boeing 747 Operations Manual used by Korean Air, activation of the pull up alert (which was desensitized in the landing configuration) requires the recovery maneuver (see section 1.17.4.3) immediately unless daytime VFR conditions exist and a positive visual verification is made that no hazards exist. The operations manual further states that flight crews should respond to terrain, don't sink, sink rate, too low gear, and glideslope alerts by correcting "flightpath and/or airplane configuration to eliminate the cause of the aural alert."
32. The flight mode annunciator (FMA), although not a part of the ILS system, indicates the mode for the FD and autopilot. The NAV mode selector switch determines what a flight crew expects to see on the FMA. "Armed" is indicated with white letters on a black background; "capture" is indicated with black letters on a green background. The radio magnetic indicator is used to determine VOR passage if the needles are set to VOR (and not to the ADF).
33. The FD is equipped with command bars. In a precision approach, the command bars provide guidance to maintain the glideslope; in a nonprecision approach, the command bars typically provide guidance to maintain the desired vertical speed.
34. The maximums for zero fuel weight, takeoff weight, and estimated landing weight were 242,630, 377,777, and 265,306 kg, respectively.
35. NOTAMs are disseminated to flight crews to provide information about conditions or changes in any aeronautical facility, service, procedure, or hazard.
36. In surface weather observations, cloud bases are measured in feet agl.
37. The term "cell" is used to describe an area of precipitation depicted on radar.
38. Chaff is aluminum foil strips dropped by military aircraft as phony targets to confuse radars.
39. Although the FAA concluded that the outer marker was functioning properly, its aural alert was not heard on the accident airplane's CVR, and the CVR contained no indication that the flight crew had seen the flashing blue light of the marker beacon indicator. However, the alert would not have been audible and the indicator would not have been seen if the flight crew had turned off the marker beacon aural alert and the marker beacon indicator. The instruments and switches related to the ILS that were found in the wreckage did not indicate the operational status of the marker beacon aural receivers and indicators.
40. The tower controller said that, at the time of the accident, the lights for runway 6L were on step 2, and the medium intensity approach lights were on step 1 (the lowest of three approach light intensity settings). These settings were not changed until after the accident when Ryan flight 789 requested that the lights on runway 24R be changed from step 2 to 3. The controller documented the runway light settings about an hour after the Ryan flight had landed and said that no one had reset the runway lighting panel during that period.
41. Andersen AFB is located at the northeastern end of the island. It has two runways that are oriented in the same manner as those at Guam International Airport.
42. The FPS-93 long-range radar system is connected to an Air Traffic Control Beacon Interrogator-5 encoder, and the ASR-8 radar system is connected to an Air Traffic Control Beacon Interrogator-4 encoder.
43. Saipan is part of the Mariana Islands.
44. At the time of the accident, ATC facilities were classified according to the number of flight operations per hour. Level I had the lowest number of flight operations; Level V had the highest number. ATC facilities are now classified under a different system that considers other factors in addition to the number of flight operations per hour.
45. TACAN stands for tactical air control and navigation. It is the U.S. military's version of DME.
46. Secondary radars transmit interrogation pulses to a receiver aboard an aircraft. The radars display altitude and identity information sent from the aircraft in response.
47. Primary radar targets only detect radar energy reflected from the structure of the aircraft itself.
48. See section 1.18.1.2 for information on Safety Board recommendations regarding the MSAW system.
49. According to FAA Order 7210.3M, "Facility Operation and Administration," section 13-2-7, MSAW and conflict alert functions can be temporarily inhibited "when their continued use would adversely impact operational priorities." The order also states that a brief written report should be sent to the FAA air traffic directorate whenever these functions are inhibited.
50. The Safety Board may hold a public hearing as part of its investigation into certain accidents to supplement the factual record of an accident investigation. The Board calls technical experts as witnesses to testify, and Board investigative staff and designated representatives from the parties to the investigation ask questions to glean factual information. The hearing is not intended to analyze any factual information for cause. The Board held a public hearing on this accident from March 24 to 26, 1998, in Honolulu, Hawaii (see appendix A). Five issues were addressed at this hearing: controlled flight into terrain (CFIT) accidents, operation of navigational devices at the Guam airport, MSAW systems and practices related to these systems, search and rescue operations, and U.S. and foreign government oversight of foreign air carriers operating into the United States.
51. Safety Board investigators and FAA representatives were not able to locate a NOTAM addressing the Guam MSAW system's inhibited status. However, the FAA stated that a NOTAM would not normally be issued for an inhibited MSAW system.
52. See section 1.18.1.1 for information on other postaccident MSAW-related actions taken by the FAA.
53. In July 1995 and April 1997, the FAA conducted standard evaluations of the Agana tower. In addition, internal biannual evaluations were conducted during July 1995 and June 1997. After these evaluations, labor hours were increased to provide dual coverage of ATC positions during peak traffic periods. Because of this action, Serco began recruitment for an additional air traffic controller in mid-July 1997. The Safety Board was advised during its on-scene accident investigation that, although approval from the FAA had not been received, an additional controller was hired on August 12, 1997.
54. D-BRITE is a radar display remote linked from approach control to the tower.
55. 56 FAA Order 7110.65, "Air Traffic Control," paragraph 10-3-1(b), states that controllers are to declare, in a timely manner, a flight that is overdue.
56. A GPS is a navigation system that provides precise, real-time information about an airplane's position.
57. The 727-200 was equipped with Rockwell International/Collins Model 51RV-1 ILS receivers.
58. The Safety Board is not aware of any other approaches that use a VOR as a step-down fix on the final approach segment of a localizer-only approach.
59. 60 The step-down approach technique requires pilots to cross specific navigational fixes at or above several altitudes while descending to the MDA, at which point the pilot either executes a landing or a missed approach. 59
60. Copies of these approach charts are contained in the Safety Board's public docket for this accident. The Board maintains a public docket for each accident it investigates. The docket is used to establish the permanent record of an accident.
61. The plan view is the approach viewed from above; the profile view is the approach viewed from the side.
62. See section 1.18.7.1 for safety recommendations regarding the need for improved FDR documentation.
63. The Safety Board ranks the quality of CVR recordings in five categories: excellent, good, fair, poor, and unusable. For a recording to be considered "good quality," most of the crew conversations need to be accurately and easily understood. The transcript developed from the recording might indicate several words or phrases that were not intelligible; such losses are attributed to minor technical deficiencies/momentary dropouts in the recording system or simultaneous cockpit/radio transmissions that obscure one another.
64. Apra Harbor is located 5 DME on the approach course.
65. Station refers to a specific location on the airplane, as measured from a data point. Examples include fuselage station, typically measured from a point forward of the nose of the aircraft, and wing station, typically measured from a point at the wing root and extending outward.
66. The captain did not advise Korean Air, before the July 28 to July 30, 1997, round trip flight from Seoul to San Francisco that he had been diagnosed with bronchitis and prescribed medications for the condition, nor did he receive medical approval from the company to conduct this trip. Korean Air's Operations Manual, chapter 4-12-4 (dated May 21, 1997), requires that a crewmember who "must be on duty under influence of medication, shall follow the direction of an Aeromedical Specialist." International Civil Aviation Organization (ICAO) Annex 1, section 1.2.6 (dated November 16, 1989), specifies that license holders should not exercise the privileges of their licenses and related ratings at any time when they are aware of any decrease in their medical fitness that might render them unable to safely exercise these privileges.
67. According to the Guam airport emergency response guidelines, ramp control is responsible for providing all communication/dispatch functions in the event of an emergency.
68. After the accident, GFD policy was changed to drain fire truck brake lines only during periodic maintenance to prevent moisture from contaminating the lines. The GFD chief stated that a fire truck would not be taken out of service without having another vehicle in its place.
69. The Federal Fire Department's Station No. 5 is responsible for providing fire protection to U.S. Naval facilities on Guam.
70. After the accident, the regional director of the Federal Emergency Management Agency stated that the agency would provide money to refurbish the command post vehicle.
71. Admittance times may be different than arrival times because patients received immediate emergency room treatment before being officially admitted to the hospital.
72. Title 14 CFR Section 139.325, "Airport Emergency Plan," paragraph (g)(4) and (5), requires the certificate holder, that is, the airport, to "at least once every 12 months, review the emergency plan with all the parties with whom the plan is coordinated...ensure that all parties know their responsibilities...and hold a full-scale airport emergency plan exercise at least once every three years...."
73. The report stated that water and foam were available on the fire trucks at the scene but that "water would have spread...fire caused by fuel" and "foam would have caused further injury to those with burns and/or open wounds." The report also added that airborne water buckets would have pushed the toxic gases and smoke onto rescuers.
74. At the time of the accident, no enhanced GPWS system had been certified for the 747-300 series airplane.
75. See Public Hearing exhibit 9F for detailed information regarding these spurious signal tests.
76. The FAA engineer indicated during his testimony that voices and music contain 90- and 150-Hz components.
77. Korean Air's Deputy Director of Flight Operations further testified that "...starting on the 1st of April [1998] the company is under contract to receive expert consultation of comprehensive nature from a wellknown and well-respected international organization."
78. The increased requirements were a 2-year freeze period as a captain on small- and medium-sized aircraft in Korean Air's fleet, 500 landing cycles on small- and medium-sized fleet aircraft, 350 landing cycles on large fleet aircraft, and 4,000 hours of flight time with the company.
79. Regarding Korean Air's revised policy on slippery runway conditions, the Immediate Action Plan stated that "wind gusts are to be taken into account when computing maximum allowable cross/tailwinds, allowable wind conditions must be adjusted to take into account braking action categories...[and] auto land approaches, new minimum stopping distances...[and] improved guidelines for determining wet runways must be observed, and more stringent takeoff and landing restrictions for marginal runway conditions have been adopted."
80. According to Korean Air's Immediate Action Plan, "automation should be at the most appropriate level. The level used should permit both pilots to maintain a comfortable workload distribution and maintain situational awareness."
81. Korean Air decided to outsource all simulator training activities to FlightSafetyBoeing. The details for this arrangement were finalized in June 1999. Korean Air expected that the outsourcing program would begin in the latter part of 1999.
82. STARs are routes established for arriving IFR aircraft. Their purpose is to simplify clearance delivery procedures and facilitate the transition between en route and instrument approach procedures.
83. Category II instrument approaches have minimums of 100 feet decision height (DH) and a runway visual range of 1,200 feet.
84. Korean Air used a 747-200 model simulator to train 747-100, -200, and -300 pilots.
85. According to Korean Air, the company began LOFT in 1992 using the 747-200. In 1993, this training was expanded to the 747-400 and the MD-82. The training eventually covered all aircraft types and models.
86. The purpose of this course is to increase team abilities to handle abnormal situations through cooperative efforts between flight and cabin crewmembers.
87. In a postaccident interview, the Deputy Director of Flight Operations stated that Korean Air had incurred 17 violations in 1996.
88. A Korean Air representative stated that the captain was responsible for reviewing applicable NOTAMs during the self-briefing and discussing any questions about them with the company dispatcher. According to the SOF, the flight crew did not indicate that there were NOTAMs regarding the flight. The SOF also indicated that he was unaware of the NOTAM regarding the inoperative glideslope.
89. Section 121.445 and safety recommendations to the FAA on special airport criteria and designation.
90. In this report, the term "landing briefing" is synonymous with "approach briefing."
91. The Boeing 747 Guidebook is a Korean Air procedures and technique training aid. It is published in Korean and English. The edition in effect at the time of the accident was dated August 1993.
92. Korean Air states that normal procedures "...are the recommended actions necessary to operate the airplane for each phase of flight. They enable the flightcrew to more readily memorize the required items, ensure that all necessary actions have been taken, and minimize the time required."
93. The constant angle of descent technique requires pilots to maintain a predetermined constant angle and constant rate of descent, which is generally calculated to be about 3?, except when terrain or an obstacle necessitates a steeper descent. When a ground-based glideslope signal is absent, pilots can fly the constant angle of descent approach by using flight management system (FMS) and GPS equipment for electronic guidance. (See section 1.10.3.1 for a description of the step-down technique.)
94. Some international air carriers have the PNF lead or prompt the PF through the nonprecision approach procedure by stating the next procedural change, including course, heading, altitude, time, visual contact, and MAP. Further, some air carriers have the captain serve as the PNF (until just before landing) and monitor the first officer's performance (as the PF) during the approach procedure.
95. Most U.S. airlines refer to this procedure as the escape maneuver.
96. Airclaims Limited is an aviation consulting firm that collects data, in part, for the aviation insurance industry. The Airclaims Limited database is recognized by the aviation industry as a definitive source for worldwide aviation accident information. Loss data for this comparison were retrieved from Airclaims Client Aviation System Enquiry database and were current as of August 10, 1999. Exposure data were retrieved from Airclaims Limited, Jet Operator Statistics, 1999, issue 1.
97. Some of these accidents occurred when Korean Air was known as Korean Airlines. For consistency, Korean Air is used throughout this section.
98. See International Civil Aviation Organization (ICAO), Destruction of Korean Air Lines Boeing 747 on 31 August 1983, Report on the Completion of the ICAO Fact-finding Investigation, June 1993.
99. As stated in section 1.17.2.3, Korean Air instituted a CRM training program in December 1986 as a result of this accident.
100. See National Transportation Safety Board. 1984. Korean Air Lines, McDonnell Douglas DC-10-30, HL7339, SouthCentral Air, Piper PA-31-350, N35206, Anchorage, Alaska, December 23, 1983. Aircraft Accident Report NTSB/AAR-84/10. Washington, DC.
101. See Libyan Civil Aviation Authority, Korean Air McDonnell Douglas DC-10-30 Korean Registration ML-7328 crashed nearby Tripoli International Airport Southeast of Runway 27 on July 27, 1989. Aircraft Accident Final Report.
102. According to Korean Air personnel, this accident resulted in upgrades of the Korean Air pilot training program, including increased instrument flight time requirements, additional GPWS awareness in simulator training, and the adoption of computer-based academic training.
103. This information was contained in an Airclaims Limited major loss record.
104. According to Korean Air, this accident led to an increased awareness of the importance of speed callouts during the approach phase of flight.
105. The KCAB subsequently suspended the captain's flying status for 1 year and the first officer's status for 6 months.
106. The KCAB subsequently suspended the captain's ATP certificate and the first officer's flying status for 1 year.
107. Delta Air Lines, Air Canada, and Air France suspended their code-sharing agreements with Korean Air after this accident.
108. In addition, as stated in section 1.6, the KCAB was responsible for approving Korean Air's Continuous Maintenance Program.
109. These designated check airmen were authorized by the KCAB to conduct proficiency checks and aircraft type rating checks. The KCAB conducted annual evaluations of the designated check airmen.
110. Virtually all countries (including South Korea) are signatory to the Chicago Convention Treaty, which established the standards and recommended practices for international civil aviation. Annex 13 addresses aircraft accident and incident investigation.
111. Annex 6 addresses the standards and recommended practices for operation of aircraft.
112. The position title for POIs assigned to foreign carriers is International Geographic Inspector (Operations).
113. One accident that raised such concerns was the January 25, 1990, crash of an Avianca Boeing 707 in Cove Neck, New York, as a result of fuel exhaustion.
114. According to the FAA, about 600 foreign air carriers operate into the United States, and about 103 countries or regional country alliances have oversight responsibilities for air carriers that either operate into the United States or have applied to operate into the United States.
115. Paragraph 9.3.1 of ICAO Annex 6 states that operators "shall establish and maintain a ground and flight training program . . . which ensures that all flight crew members are adequately trained to perform their assigned duties. [The training program] shall also include training in knowledge and skills related to human performance and limitations...[and] shall ensure that all flight crew members know the functions for which they are responsible and the relation of those functions to the functions of other crew members."
116. This policy is defined in a notice published in the Federal Register, Volume 60, No. 210, October 31,1995.
117. The FAA does not assess a country's compliance with Annex 13. The Safety Board notes that, during the Accident Investigation Group (AIG) divisional meeting held by ICAO from September 14 to 24, 1999, AIG delegates adopted a recommendation for the ICAO Council to take steps to expand the ICAO safety oversight audit program to include an assessment of a country's compliance with Annex 13. The program currently assesses a country's compliance with Annexes 1, 6, and 8.
118. 119 The FAA indicated that, in August 1998, the agency's Administrator had approved the transition to Phase 2 but that the change would not take effect until publication of a notice in the Federal Register.
119. According to the DOT/IG report, the six airlines are American, Continental, Delta, Northwest, Trans World, and United.
120. The DOT/IG report indicated that a "code share team," comprising representatives from the DOT and the FAA, was developing recommendations to address many of the issues discussed in the audit report. The report noted that, once the recommendations are accepted by DOT and FAA management, additional time and effort would be required to develop policies and procedures to implement those recommendations.
121. The FAA indicated that one MSAW function--at the Aspen/Pitkin Airport in Colorado--was not in service because of the "large number of false low-altitude alerts in the mountainous terrain." The FAA also indicated that "aviators have been notified of this condition."
122. 123 National Transportation Safety Board. 1973. Eastern Air Lines, Inc. L-1011, N310EA, Miami, Florida, December 29, 1972. Aircraft Accident Report NTSB/AAR-73/14. Washington, DC.
123. National Transportation Safety Board. 1990. USAir Flight 105, Boeing 737-200, N283AU, Kansas City International Airport, Missouri, September 8, 1989. Aircraft Accident Report NTSB/AAR-90/04. Washington, DC.
124. National Transportation Safety Board, Controlled Collision With Terrain, Transportes Aereos Ejecutivos, S.A. (TAESA), Learjet 25D, XA-BBA, Dulles International Airport, Chantilly, Virginia, June 18, 1994. Aircraft Accident Report NTSB/AAR-95/02. Washington, DC.
125. The Safety Board investigated another accident involving discrepancies with an MSAW system. On January 13, 1998, a Gates Learjet 25B, N627WS, operated by American Corporate Aviation, Inc., of Houston, Texas, crashed approximately 2 nm east of the runway 26 threshold at George Bush Intercontinental Airport in Houston, Texas, during an ILS approach. (See Brief of Accident FTW98MA096 for more information.) The investigation revealed, among other things, that the MSAW system at the airport was not configured in accordance with the guidance provided in FAA technical document NAS-MD-633, "Minimum Safe Altitude Warning." The Board identified two MSAW-related errors: the altitude computations for runway 26 were based on the ILS DH instead of the localizer-only MDA, and the ILS data should not have been used at all because other nonprecision approaches to the runway were available. At the time of the accident, the MSAW threshold altitude for runway 26 was incorrectly set to 100 feet agl. Proper application of the procedures contained in NAS-MD-633 would have resulted in a threshold setting of 402 feet agl. This accident is also included in the discussion of Safety Recommendations A-95-35 and A-99-36 in section 1.18.2.4.
126. The Safety Board also issued Safety Recommendation A-94-186, which asked the FAA to review the calculations establishing the runway threshold coordinates for all runways at Dulles International Airport with respect to the air surveillance radar to verify proper alignment of the MSAW capture boxes. On November 20, 1995, the Safety Board noted that the FAA had completed its review of the calculations and adaptation values for runway threshold coordinates for all runways at the airport and had verified proper alignment of the capture boxes. Therefore, Safety Recommendation A-94-186 was classified "Closed-- Acceptable Action."
127. According to FAA inspection records, the Guam CERAP ARTS IIA facility was reviewed in July 1995.
128. See Brief of Accident ATL95FA046 for more information.
129. FAA Order 7110.65, "Air Traffic Control," states that "...unless otherwise authorized, tower radar displays are intended to be an aid to local controllers in meeting their responsibilities to the aircraft operating on the runways or within the surface area." The order also states that "...local controllers at non-approach control towers must devote the majority of their time to visually scanning the runways and local area; an assurance of continued positive radar identification could place distracting and operationally inefficient requirements upon the local controller."
130. See Brief of Accident IAD97FA001 for more information.
131. For information on the GPWS installed on Korean Air flight 801, see section 1.6.2.2.
132. Radio altitude is derived from the radio altimeter, also called the radar altimeter. The radio altimeter does not require an accurate barometric pressure setting; rather, it displays the height above the ground by using time-varying frequency and measuring the differences in the frequency of received waves, proportional to time and height.
133. For information on the aural alerts that would have been generated by enhanced GPWS for flight 801, see section 1.16.1.
134. In the NPRM, the FAA used the term "TAWS" when referring to enhanced GPWS because the FAA expected that a variety of systems could be developed to meet the improved standards proposed in the NPRM.
135. An AC provides nonregulatory guidance to certificate holders for compliance with the FARs.
136. These airplanes were not required by the FARs to be equipped with a GPWS.
137. Investigation of Controlled Flight Into Terrain, Aircraft Accidents Involving Turbine-Powered Aircraft with Six or More Passenger Seats Flying Under FAR Part 91 Flight Rules and the Potential for Their Prevention by Ground Proximity Warning Systems, DOT-TSC-FA6D1-96-01, 1996.
138. Investigation of Controlled Flight Into Terrain, Selected Aircraft Accidents Involving Aircraft Flying Under FAR Parts 121 and 135 Flight Rules and the Potential for Their Prevention by Enhanced Ground Proximity Warning System (EGPWS), DOT-TSC-FA6D1-96-03, 1996.
139. National Transportation Safety Board. 1971. Southern Airways, Inc., Douglas DC-9-15, N92S, Gulfport, Mississippi, February 17, 1971. Aircraft Accident Report NTSB/AAR-71/04. Washington, DC.
140. National Transportation Safety Board. 1972. 'Northeast Airlines, Inc., McDonnell Douglas DC-9-31, N982NE, Martha's Vineyard, Massachusetts, June 22, 1971. Aircraft Accident Report NTSB/AAR-72-04. Washington, DC. 140
141. National Transportation Safety Board. 1972. Southern Airways, Inc., DC-9, N97S, Tri-State Airport, Huntington, West Virginia, November 14, 1972. Aircraft Accident Report NTSB/AAR-72-11. Washington, DC.
142. For more information on the Bar Harbor, Henson, and Simmons Airlines accidents, see Briefs of Accident DCA85AA035, DCA85AA037, and DCA86AA021, respectively.
143. National Transportation Safety Board. 1992. Bruno's, Inc., Beechjet 400, N25BR, Rome, Georgia, December 11, 1991. Aircraft Accident Report NTSB/AAR/92-01/SUM. Washington, DC.
144. See Safety Recommendation A-94-187 in section 1.18.1.2 for additional information about this accident.
145. See section 1.18.2.3 for more information about this study.
146. Between the time of the Safety Board's August 1995 letter and the FAA's April 1997 letter, the Volpe study was issued, and an American Airlines CFIT accident involving traditional GPWS occurred. (This accident is discussed in the Safety Recommendation A-96-101, which is the next recommendation presented.)
147. Safety Recommendation A-95-35 was superceded by A-99-36.
148. The investigation of this accident was conducted by the Aeronautica Civil of the Government of Colombia, with assistance from the Safety Board. For more information, see the Aeronautica Civil of the Government of Colombia Aircraft Accident Report, Controlled Flight Into Terrain, American Airlines Flight 965, Boeing 757-223, N651AA, Near Cali, Colombia, December 20, 1995.
149. See the discussion in Safety Recommendation A-99-36 for detailed information on TSO C151.
150. "A Study of Fatal Approach-and-landing Accidents Worldwide, 1980-1996," Flight Safety Digest, February-March 1998. This study was also included as part of a special FSF report, "Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents," Flight Safety Digest, November-December 1998 and January-February 1999.
151. The study's data indicated that, of the 287 approach and landing accidents, 108 occurred on initial approach, 82 on final approach, and 97 on landing.
152. Of the 287 accidents in the study, 8 were judged to have insufficient information available to determine a primary causal factor.
153. Omission of action/inappropriate action was identified in 69 accidents, lack of positional awareness in 52 accidents; flight handling in 34 accidents, "press-on-itis" in 31 accidents, and poor professional judgment/airmanship in 12 accidents.
154. According to the FSF report, "considering the causal groups, rather than individual factors, "crew" featured in 228 of the 279 accidents (82 percent)...."
155. These conclusions and recommendations were presented at the FSF's Corporate Aviation Safety Seminar, held May 5 through 7, 1998.
156. The captain stated that only three CFIT accidents during that time period occurred on precision approaches and that these accidents experienced a probable failure of the glideslope receiver, a probable failure of the FD to capture, and a possible situation in which the autopilot was not coupled.
157. The captain also indicated that ICAO was considering whether to publish a manual on CFIT avoidance.
158. See section 1.18.2.4 for more information about this accident.
159. The Aeronautica Civil of the Government of Colombia issued the following CFIT-related recommendations to the FAA: (1) require that all approach and navigation charts used in aviation graphically portray the presence of terrain located near airports or flightpaths, (2) encourage manufacturers to develop and validate methods to present accurate terrain information on flight displays as part of a system of early ground proximity warning, (3) develop a mandatory CFIT training program that includes realistic simulator exercises that are comparable to the successful windshear and rejected takeoff training programs, and (4) evaluate the CFIT escape procedures of air carriers operating transport-category aircraft to ensure that the procedures provide for the extraction of maximum escape performance and ensure that those procedures are placed in operating sections of the approved operations manuals. In addition, the Aeronautica Civil recommended that ICAO evaluate and consider adopting the recommendations of the FSF's CFIT task force (see appendix C).
160. The Safety Board reiterated Safety Recommendation A-96-94 on July 15, 1997. See National Transportation Safety Board. 1997. Uncontrolled Flight Into Terrain, ABX (Airborne Express), Douglas DC-8-63, N827AX, Narrows, Virginia, December 22, 1996. Aircraft Accident Report NTSB/AAR-97/05. Washington, DC.
161. Angle-of-attack is the angle of the airplane wing to the relative wind.
162. The Safety Board issued this recommendation because Jeppesen Sanderson was changing the portrayal of terrain on some, rather than all, of its charts. Specifically, Jeppesen was revising approach charts only if they displayed terrain that was above 2,000 feet within 6 miles of an airport; local area charts were being revised only if they displayed terrain that was more than 4,000 feet above the plan view of an airport.
163. National Transportation Safety Board. 1991. Controlled Flight Into Terrain, Markair Flight 3087, Boeing 737-2X6C, N670MA, Unalakleet, Alaska. Aircraft Accident Report NTSB/AAR-91/02. Washington, DC.
164. For more information, see the Air Force's Accident Investigation Board Report, United States Air Force CT-43A [Boeing 737], 73-1149, 3 April 1996, at Dubrovnik, Croatia.
165. 166 See Air Line Pilots Association Report on Accident Involving Korean Air Flight 801 at Agana, Guam, on August 6, 1997, dated June 24, 1998.
166. National Transportation Safety Board. 1996. Collision With Trees on Final Approach, American Airlines Flight 1572, McDonnell Douglas MD-83, N566AA, East Granby, Connecticut, November 12, 1995. Aircraft Accident Report NTSB/AAR-96/05. Washington, DC.
167. 168 See National Transportation Safety Board. 1994. A Review of Flightcrew-Involved Major Accidents of U.S. Air Carriers, 1978 Through 1990. Safety Study NTSB/SS-94/01. Washington, DC.
168. For a discussion of previous accidents in which the Safety Board determined that fatigue was a factor, see section 1.18.6.
169. Orasanu, Judith, Martin, Lynne, and Davison, Jeannie. Errors in Aviation Decision Making: Bad Decisions or Bad Luck? NASA Ames Research Center, Moffett Field, California. Presented to the Fourth Conference on Naturalistic Decision Making, Warrenton, Virginia, May 29-31, 1998.
170. National Transportation Safety Board. 1994. In-flight Loss of Control, Leading to Forced Landing and Runway Overrun, Continental Express, Inc., Embraer EMB-120RT, N24706, Pine Bluff, Arkansas, April 29, 1993. Aircraft Accident Report NTSB/AAR-94/02/SUM. Washington, DC.
171. All times for this accident are central standard time, based on a 24-hour clock.
172. Human fatigue in transport operations was listed as one of the Safety Board's May 1999 Most Wanted Transportation Safety Improvements.
173. National Transportation Safety Board. 1994. 'Uncontrolled Collision With Terrain, American International Airways Flight 808, Douglas DC-8-61, N814CK, U.S. Naval Air Station, Guantanamo Bay, Cuba, August 18, 1993. Aircraft Accident Report NTSB/AAR-94/04. Washington, DC.
174. At the public hearing on this accident, the chief crew scheduler for American International Airways testified that this flight assignment would have resulted in an accumulated flight time of 12 hours, which was within the company's "24-hour crew day policy."
175. The strobe light was to be used as visual reference during the approach. The flight crew was not advised, however, that the strobe light was inoperative.
176. National Transportation Safety Board. 1999. Evaluation of U.S. Department of Transportation Efforts in the 1990s to Address Operator Fatigue. Safety Report NTSB/SR-99/01. Washington, DC.
177. Safety Recommendation A-89-1 asked the DOT to expedite a coordinated research program on the effects of fatigue, sleepiness, sleep disorders, and circadian factors on transportation system safety. Safety Recommendation A-89-2 asked the DOT to develop and disseminate educational material for transportation industry personnel and management regarding shift work; work and rest schedules; and proper regimens of health, diet, and rest. Safety Recommendation A-89-3 asked the DOT to review and upgrade regulations governing hours of service for all transportation modes to ensure that they are consistent and that they incorporate the results of the latest research on fatigue and sleep issues.
178. As of November 1999, the Safety Board had not received a response on this recommendation from the DOT.
179. The Board encountered problems extracting data from retrofitted FDRs recovered from the following accidents and incidents: Express One, Boeing 727, Orebro, Sweden, November 12, 1996; Millon Air, Boeing 707, Manta, Ecuador, October 22, 1996; ValuJet, DC-9, Miami, Florida, May 11, 1996; ValuJet, DC-9, Savannah, Georgia, February 28, 1996; ValuJet, DC-9, Nashville, Tennessee, February 1, 1996; ValuJet, DC-9, Nashville, Tennessee, January 7, 1996; Millon Air, DC-8, Guatemala City, Guatemala, April 28, 1995; and Air Transport International, DC-8, Kansas City, Missouri, February 16, 1995. The lack of adequate documentation of these FDR systems prevented accurate and complete readouts of the FDR data and, consequently, a clear understanding of the circumstances surrounding the accidents.
180. The FAA adopted rulemaking to require airlines to retrofit FDRs on most U.S.-registered aircraft.
181. 182 National Transportation Safety Board. 1997. Descent Below Visual Glidepath and Collision With Terrain, Delta Air Lines Flight 554, McDonnell Douglas MD-88, N914DL, LaGuardia Airport, New York, October 19, 1996. Aircraft Accident Report NTSB/AAR-97/03. Washington, DC.
182. The first officer indicated his belief that LaGuardia should be designated as a special airport and that approaches to runways 13 and 31 were worthy of special pilot qualification requirements.
183. This rule was adopted in June 1980.
184. The version of AC 121.445 that was in effect at the time of the accident was dated June 1990.