convert the recorded information into engineering units.[1] 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,[2] 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.
- ↑ See section 1.18.7.1 for safety recommendations regarding the need for improved FDR documentation.
- ↑ 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.
