| United Airlines Flight 811 |
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divers]] United Airlines Flight 811 experienced an Explosive Decompression on February 24 , 1989 after take-off from Honolulu International Airport , Honolulu , Hawaii . The explosion, caused by a malfunctioning Cargo door that opened during flight, ripped out several rows of seats with 9 passengers, who were killed when ejected from the aircraft, but the airplane landed safely. INCIDENT United Airlines Flight 811, a Boeing 747 -122 (registration number N4713U), took off from Honolulu International Airport bound for Sydney, Australia , via Auckland, New Zealand with 3 flightcrew, 15 flight attendants, and 337 passengers aboard. As it was climbing between 22,000 and 23,000 feet, a grinding sound was felt for 30 seconds — the cargo door was opening. As it opened fully an explosive decompression occurred, and five rows of business class seats on top of the cargo door were blown out of the aircraft, along with nine passengers. Severely injured, a flight attendant was lying down beside the hole caused by the decompression. This also happened to knock out the aircraft's oxygen supply. The pilots plunged the Boeing 747 into a nosedive so they could get to an altitude that would allow the crew to breathe again. The explosion had knocked the number 3 engine out and the number four engine caught fire. Even with only partial flaps and concerns over landing gear and structural integrity of the airplane the crew made a perfect landing and were able to deploy all ten evacuation slides on the aircraft. CAUSE The incident was caused by a combination of improper wiring in the R5 cargo door latching mechanism. At the time, the design of the 747-122 provided a small window situated flush against each of the cargo doors, so that the ground crew could visually confirm that the doors' latches were set to the locked position. There were, however, several flaws in this design. It didn't allow a particularly close look at the door latches, and it didn't show the entire latching mechanism, which made the complete inspection of the latched door impossible. With these factors in place, an accident was bound to occur, and finally did on this flight. The R5 door, being an outward-opener, blew open and separated from the Fuselage . It took a 15x3 foot section of the aircraft's fuselage with it, leaving the passenger cabin exposed to the elements at 22,000 feet. At this point the aircraft was approximately 20 miles from Honolulu, and managed to make a safe turnaround and a safe landing, after which an evacuation was immediately carried out. RESULT The NTSB issued an emergency recommendation {Link without Title} for all 747-100s in service at the time to replace their cargo door latching mechanisms with new, non-faulty locks. A subrecommendation suggested replacing all outward-opening doors with inward-opening doors, which cannot open in flight due to the pressure differential. No similar accidents have occurred on 747-100s since this accident. The flight crew (none of whom were ejected during the explosion) received the {Link without Title} Secretary's Award for Heroism for their actions later in 1989. The aircraft was successfully repaired, re-registered as N4724U, and returned to service in 1990. United Airlines ran a simulation through a flight simulator and were, despite many attempts and variable tweaks, unable to successfully land a plane after losing the R5 door. A fictionalized version of the accident, suggesting alien involvement, was portrayed in the TV show '' The X-Files .'' SEE ALSO EXTERNAL LINKS
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