Pilots' failure to notice clues that they were heading to the wrong runway was the primary cause of last summer's deadly Kentucky plane crash that killed 49 persons, safety investigators concluded yesterday.
The National Transportation Safety Board deliberated all day on suspected causes of the Aug. 27, 2006, crash of Comair Flight 5191, which tried to depart in the pre-dawn darkness from an unlit general aviation strip too short for a proper takeoff.
Board members originally had considered listing errors by the air traffic controller as contributing causes but ultimately pinned most of the blame on the pilots, along with the Federal Aviation Administration for failing to enforce earlier recommendations on runway checks.
NTSB board member Deborah Hersman suggested during the meeting that there were numerous causes — nearly all of them human.
"That's the frustration of this accident — no single cause, no single solution and no 'aha' moment," she said. "Rather than pointing to a mechanical or design flaw in the aircraft that could be fixed or a maintenance problem that could be corrected, this accident has led us into the briar patch of human behavior."
The NTSB also proposed several changes to aviation procedure as a result of the accident, including calls for clearer signs at regional airports and installation of an automated moving map system in which pilots can check in real time whether they are on the right runway.
Comair said it would work with the NTSB and the FAA to address the proposed changes.
Among the non-factors, according to the board, were the flight crew's lack of updated maps and notices alerting them to construction that had changed the taxiway route a week earlier. Although the board found the controller was fatigued, that also likely didn't play a role, the board said.
Pilot Jeffrey Clay and first officer James Polehinke were most culpable for ignoring clear signs they were going the wrong way, such as the lack of lights on the shorter runway, NTSB found. "Weird, no lights," Mr. Polehinke was quoted as saying in the cockpit transcript.
NTSB Chairman Mark Rosenker said afterward that there were clear differences between the right strip and the wrong one.
"One was lit up like a Christmas tree," he said. "The other was like a black hole."
Mr. Polehinke was pulled from the charred cockpit as the only survivor, but he sustained brain damage, lost a leg and broke numerous bones. His attorney, Bruce Brandon, declined to comment yesterday.
A secondary cause, NTSB said, was non-pertinent chatter between the crew members as they prepared to taxi and take off. Comair has acknowledged some culpability as a result of the talk, which violated FAA rules calling for a "sterile cockpit."