Malfunction in Jet Cargo Door Blamed for Fatal 1989 Accident
Federal safety officials reversed course Wednesday and said that their examination of a Boeing 747 cargo door recovered from the Pacific Ocean shows an electrical malfunction caused the 1989 accident that killed nine passengers aboard United Airlines Flight 811.
The National Transportation Safety Board originally concluded that the cargo door ripped free from the aircraft’s fuselage because of United’s failure to make sure it was properly latched and maintained.
That conclusion was reached in April, 1990, before the dramatic expedition that located the cargo door and plucked it from the seabed, 14,000 feet below the surface. The door was successfully raised from the ocean by Navy ships in the fall of 1990.
With that piece of evidence, the safety board said it became clear that the probable cause of the accident was a faulty switch or electrical wiring in the door control system. This permitted the “uncommanded electrical operation” of the door latches after the door had been closed, locked and latched, it concluded.
In a new recommendation, the safety board has urged the Federal Aviation Administration to require the cutoff of electrical power to Boeing 747 cargo doors after they have been locked and latched “to prevent the possibility of electric short circuits from causing the doors to open uncommanded.”
The accident occurred Feb. 13, 1989, after Flight 811 took off from Honolulu en route to New Zealand and Australia. Nine passengers were sucked from their seats after the cargo door ripped off, taking part of the fuselage with it.
The board’s report absolved United of blame in the accident, and board members praised the professionalism and expertise of the crew members who safely landed the plane at Honolulu despite the gaping hole in its side and the loss of power in two engines.
Susan Coughlin, the safety board’s acting chairwoman, said the board’s original finding that Boeing was at fault for not making the locking system foolproof stands as written.
