Task Management: Exemplar Case Study
Shortly before midnight on 29 December 1972, an Eastern Airlines Lockheed L-1011 was on approach to Miami airport, completing its regular evening flight EAL 401 from JFK International Airport in New York. As the aircraft made its final approach to Miami, the landing gear was selected down for landing. However, almost immediately, the first officer noticed that the green light to indicate that the nose-wheel was down and locked in position had failed to illuminate. The captain recycled the landing gear lever, but again the green light failed to illuminate.
The crew, identifying that they would not be able to resolve the situation prior to touchdown, called Miami air traffic control and indicated that they would not yet be able to land. Air traffic control cleared flight EAL 401 to climb back up to 2000 feet and to turn north then west, flying away from the airport.
Once the aircraft reached 2000 feet, the autopilot was engaged, and the crew began to troubleshoot the problem. The first officer removed the light assembly, but then it jammed when he was trying to replace it on the instrument panel. While the captain and the first officer discussed repairing the light assembly, the captain requested the flight engineer to go down into the avionics bay below the flight deck and see whether he could visually confirm that the nose-wheel landing gear was locked in the down position.
While the crew were focussing on the problem, somehow the autopilot disconnected, most likely because one of the crew members unwittingly placed pressure on their control wheel. Due to their focus on the landing gear problem, no one heard the altitude alert tone to indicate that the aircraft was descending. Quietly and smoothly, the aircraft slowly descended towards the Florida everglades. Only at the very last minute, and at this stage too late to recover the aircraft, did the flight crew realise they had lost altitude. The aircraft crashed at 2342, only 10 minutes after the crew had first identified the problem with the landing gear light. A total of 101 passengers and crew perished as a result of the accident. Remarkably, 75 survived.
The National Transport Safety Board report into the accident identified the probable cause as the flight crew’s failure to monitor the flight instruments in the final four minutes of the flight, allowing the descent to go unnoticed and unchecked.2
The trajectory of this tragic accident began with the most simple of problems, a faulty light. However, sub-optimal task management led to all crew members becoming pre-occupied with the light, and no one was left to fly the aeroplane.