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[1] 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)[2] 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."[3] About 0141:53, the CVR recorded the sound of the windshield wipers starting. The windshield wipers remained on throughout the remainder of the flight.
- ↑ 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.
- ↑ 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.
- ↑ 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.
