Korean Air conceded Wednesday that the cockpit crew of its Flight 801 apparently ignored several important piloting procedures as the jetliner sank dangerously low before slamming into a hill last summer while attempting to land in Guam.
Pilot error is the suspected cause of the Aug. 6 crash that killed 228 of the 254 aboard the Boeing 747, and Wednesday’s testimony by Jung Taek Lee, the airline’s chief of flight crew operations, did little to dispel that suspicion.
Transcripts of cockpit voice recordings recovered from the wreckage show confusion in the cockpit, with crew members questioning one another repeatedly about the state of the instrument landing system and failing to follow procedures that would have kept them all aware of how close they were getting to the ground.
“The crew’s compliance with [these] procedures was less than we are taught,” Lee told investigators Wednesday during the second day of National Transportation Safety Board hearings on the crash.
Lee was asked about the crew’s failure to specifically acknowledge an air traffic controller’s warning that Guam had no operating glide slope--a component of the instrument landing system that shows pilots whether they are descending at the correct angle.
There is a commonly used alternative component that the flight crew could have utilized, but they never could decide whether the glide slope was working.
Lee said that in situations where information from controllers is “very important,” Korean Air pilots are supposed to read it back to confirm that they have understood it. In this case, there is little doubt that the information was very important.
In addition, Lee noted that after adopting a plan to descend to the airport in a series of steps, the crew ignored airline procedures and failed to note when the descending plane had reached the minimum approved altitude for each step. As a result, the jetliner dropped far below the safe approach path.
In the final seconds before the crash, an on-board radar device--the ground proximity warning system--barked out repeated altitude readings showing that the plane was dangerously close to the ground. Lee said the crew members should have called these readings to each other’s attention, but they failed to do so.
Instead, the crew, apparently oblivious to the impending disaster, continued to run calmly through a routine prelanding checklist, not attempting to pull the plane up until it was too late.
Some senior airline pilots have said this failure to know exactly what was going on--known in the trade as a “lack of situational awareness"--is probably the key to the crash.
However, the hearings have demonstrated that confusion about Flight 801 was not limited to the cockpit. During Wednesday’s hearing, investigators posed questions to Lee in English, which were translated into Korean. Lee’s Korean responses were translated back into English.
Some exchanges ricocheted back and forth for as long as five minutes before exasperated translators finally announced that Lee’s answer to a question was simply “yes,” or “no.”
Suspicions that something was being lost in the process led to changes in translators, but both sides continued to express concerns that they were not being fully understood.