Pilot Error Is Focus of Hearings on Korean Air Jet Crash

Apparent pilot error--and some cultural factors and procedural glitches that might have contributed to it--will be the focus of attention as hearings begin here today on the crash of a Korean Air jumbo jet in Guam last summer that killed 228 of the 254 on board.

Investigative documents released Monday show that despite repeated warnings from an on-board radar system that their Boeing 747 was dangerously low, the cockpit crew failed to react.

The documents also show that there were other mistakes, oversights and distractions--seemingly trivial individually, but perhaps crucial collectively--that may have played a part in the crash of Flight 801.

Within two days of the Aug. 6 tragedy, George Black, the National Transportation Safety Board member heading the investigation, said human error “probably was a major factor” because the flight crew seemed to have been in control of the plane when it slammed into a hill while on final approach to the airport at Agana.

Black refused to say whose error that might have been, but the prime candidates seem to be the pilot and co-pilot. Why the crew strayed below the normal final approach path is not clear. Cockpit voice recordings recovered from the wreckage will be made public today.

The reports made available Monday show that the plane itself had no mechanical problems.

A radio beam navigational aid--called a glide slope--was not operating, but the cockpit crew had been notified about this at least three times that day and had available a commonly employed alternative system to make what sources close to the investigation say should have been a routine landing.

Radar equipment on the ground that should have warned air traffic controllers that Flight 801 was dangerously low failed to work properly because it had been desensitized to eliminate insignificant “nuisance alerts.”

An aural alarm had been turned down too low for the controller to hear it, and--because he was facing in the wrong direction--he failed to see a flashed warning on a radar screen.

But Black has stressed that although this ground-based radar “could have made a difference,” it is a redundant system that “does not relieve the pilot of responsibility.”

On board the plane was another ground-proximity radar system, and reports released Monday showed that it warned the crew repeatedly--through a cockpit loudspeaker system--that the jetliner was far below where it should have been.

About 45 seconds before the crash, the loudspeaker shouted that the plane was only 1,000 feet above the ground when it should have been about twice that high.

Five seconds before the crash, the system warned that the plane was down to 100 feet. It then “began a rapid succession of radio call-outs--’50! 40! 30! 20!’ ” the documents said. There was the sound of impact, and then silence.

There is no indication that the cockpit crew reacted at all until the last four seconds, when they apparently started to pull the nose up and rev the engines. By then it was too late.

The plane crashed into a lush green ridge, carving half-mile-long furrows in the red earth before it broke up, skidded to a halt and burst into flames.

A passenger later told investigators that until he saw the plane begin to break up and burn, he thought it had simply been a hard landing.

“He got out of his seat and headed toward the aisle toward the rear, where there was a great gaping hole,” an NTSB investigator wrote. “There was a ball of flame going down the center of the airplane, and passengers were screaming and luggage bins were caving in on them.”

The man, who was not identified, told investigators that it was not until he attempted to stand up after crawling out through the wreckage that he realized that his leg was broken.

The transcript of conversations in the cockpit is confidential, but questions have arisen whether there is something about the Korean culture--a traditional deference to command authority--that may have stifled any urge by the subordinate co-pilot and flight engineer to suggest to the captain that a crash could be imminent.

The director of academic training for Korean Air flight crews conceded that when so-called cockpit-management training began about 10 years ago, “there were some cultural difficulties with the curriculum and there were also difficulties teaching the first officer and flight engineer to intervene,” an NTSB report states.

However, the director went on to say that “advocacy is no longer a problem at Korean Air.”

Advocacy training was initiated at Korean Air after one of its 747s strayed--apparently inadvertently--into then-Soviet airspace in 1986 and was shot down.

In reviewing the history of the flight, NTSB investigators learned that although the cockpit crew of Flight 801 had been notified officially about the inoperative glide slope at Guam, Korean Air’s supervisor of flight failed to discuss it with them--as he should have--during the regular preflight briefing.

A recorded message from the Agana tower repeated the message about the glide slope, but it is not known whether the cockpit listened to it, as required by federal regulations.

About three minutes before the crash, when air traffic controllers reminded Flight 801 that the glide slope was inoperative, the cockpit crew failed to acknowledge the message and the controllers failed to ask if the crew had heard it.

The cockpit voice recording shows that there was subsequent conversation by the crew about the glide slope, but the details of that conversation have not been revealed. How confusion about the glide slope might have contributed to the accident is not clear.

Transcripts show that the controllers who were handling Flight 801 were also guiding other airplanes. Sources close to the investigation say there probably were periods during its final moments when its errant path went unmonitored from the ground.