American Airlines Blames Code in Computer for Colombia Crash

The captain of an American Airlines jet that crashed in Colombia last December entered an incorrect one-letter computer command that sent the plane into a mountain, the airline said Friday.

The crash killed all but four of the 163 people aboard.

American’s investigators concluded that the captain of the Boeing 757 apparently thought he had entered the coordinates for the intended destination, Cali.

But, on most South American aeronautical charts, the one-letter code for Cali is the same as the one for Bogota, 132 miles in the opposite direction, even though the codes for the two cities are different in most computer databases.

The coordinates entered for Bogota directed the plane toward the mountain, according to a letter by Cecil Ewell, American’s chief pilot and vice president for flight.

American spokesman John Hotard confirmed Friday that Ewell’s letter, first reported in the Dallas Morning News, is being delivered this week to all of the airline’s pilots to warn them of the coding problem.

American’s discovery also prompted the Federal Aviation Administration to issue a bulletin to all airlines, warning them of inconsistencies between some computer databases and aeronautical charts, the newspaper said.

The computer error is not the final word. Findings from a Colombian government investigation are expected by October. Pat Cariseo, spokesman for the National Transportation Safety Board, said Colombian investigators are also examining factors such as flight-crew training and air-traffic control.

The computer mistake was found by investigators for American, based in nearby Fort Worth, when they compared data from the jet’s navigation computer with information from the wreckage, Ewell said.

The data showed the mistake went undetected for 66 seconds while the crew scrambled to follow an air-traffic controller’s orders to take a more direct approach to the Cali airport. Three minutes later, the plane crashed while the crew was still trying to figure out why it had turned.

Ewell said the crash presented two important lessons for pilots.

“First of all . . . you can never, never, never assume anything,” he told the newspaper. Second, he said, pilots must understand they can’t let automation take over responsibility for flying the airplane.