What happened
Flight 811 was a scheduled passenger service operating from Los Angeles to Sydney, Australia, with planned stops in Honolulu (Hollolulu/HNL), Hawaii, and Auckland, New Zealand. The flight proceeded without incident following its departure from HNL.
While the aircraft was climbing from FL220 to FL230, the crew heard a thump followed by an explosion. This resulted in an explosive decompression. Due to the presence of foreign object debris (FOD), the #3 and #4 engines were shut down. The flight subsequently returned to HNL, where passengers were evacuated.
During the event, nine passengers were ejected from the aircraft and lost at sea. The separation of the door caused extensive damage to the cabin and fuselage in the area adjacent to the door.
The investigation
The investigation focused on the forward lower lobe cargo door. Post-flight inspection revealed that this door departed the aircraft during flight. The inquiry examined the design and certification of the door, specifically regarding its susceptibility to being improperly latched. Additionally, investigators looked into the operation and maintenance procedures required to ensure the airworthiness of both the door and its latching mechanism.