United Airlines Flight 811, a Boeing 747-100, was operating as a scheduled flight from Honolulu, Hawaii, to Auckland, New Zealand, when it experienced a sudden and severe decompression incident shortly after takeoff. The flight was carrying 349 passengers and crew members. At approximately 23,000 feet, a cargo door malfunctioned due to improper maintenance, leading to an explosive decompression. This catastrophic event caused an immediate loss of cabin pressure and resulted in the violent ejection of nine passengers from the business-class section of the aircraft. The passengers who were ejected were not wearing seatbelts at the time, which tragically exacerbated the situation.

Despite the chaos inside the cabin, the flight crew acted quickly to regain control of the aircraft. Captain David H. Haan and First Officer Kevin R. Bough designed an emergency procedure that allowed them to divert back to Honolulu, where they successfully landed the plane approximately 15 minutes after the incident. Upon landing, emergency personnel met the aircraft to assist the remaining passengers and secure the site, while a thorough investigation into the failure of the cargo door began immediately.

The National Transportation Safety Board (NTSB) launched an investigation, which uncovered significant lapses in maintenance practices related to the aircraft's cargo doors. This incident raised serious concerns about aircraft safety regulations and maintenance protocols industry-wide, subsequently leading to changes in safety measures enforced by the Federal Aviation Administration (FAA) and regulations for cargo door designs in commercial aircraft.