- ACCIDENT DETAILS
Date: February 24, 1989
Time: 0209
Location: Honolulu, Hawaii
Operator: United Air Lines
Flight #: 811
Route: Los Angeles - Honolulu - Auckland - Sydney
AC Type: Boeing B-747-122
Registration: N4713U
cn / ln: 19875/89
Aboard: 356   (passengers:338  crew:18)
Fatalities: 9   (passengers:9  crew:0)
Ground: 0
Summary: After leaving Honolulu, on a flight from Los Angeles to Sydney, Australia, the loss of an improperly latched forward lower lobe cargo door resulted in explosive decompression and loss of power in the No. 3 and 4 engines. Nine passengers were sucked out of the plane and lost at sea. The plane landed safely. The cargo door opening was attributed to a faulty switch or wiring in the door control system which permitted electrical actuation of the door latches towards the unlatched position after initial door closure and before takeoff. As a failsafe, the latches should have been blocked from moving by a mechanism called a "locking sector" (one on each latch), engaged manually by a lever after the door is closed. However, the locking sectors as designed were not strong enough and could be overcome by the motors which was a design flaw right from the introduction of the747. This was finally recognized as serious, after a non-fatal failure in 1987, but installing stronger locking sectors required taking each plane out of service 10 hours, and the FAA had allowed airlines 18 months so they could do it during other maintenance procedures.
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