United Airlines Boeing 747-122

On February 24, 1989, a United Airlines Boeing 747-122 flew from San Francisco to Sydney. After taking off from Honolulu (Hawaii, intermediate landing site), the crew began to bypass the storm front. Expecting strong turbulence, the captain left the "fasten your seat belts" sign on. This circumstance subsequently saved many lives.

 17 minutes after takeoff at an altitude of 7000 meters, a rattle was heard in the business class cabin. Then came the blow. A second and a half later, the tailgate came off along with part of the fuselage, forming a large hole in the body. It pulled 10 seats with 9 passengers. One of the flight attendants also began to be dragged outside, but she managed to catch her foot on the chair. Passengers managed to drag her back.

 Initially, the pilots assumed that a bomb had exploded. Depressurization at an altitude of 7000 meters caused breathing problems, so they began to drop sharply. After descending, the crew headed back to Hawaii.

The door and fuselage debris damaged the right wing, tail and both right engines. They had to be turned off and continue flying with the remaining two. Due to partially damaged flaps, the aircraft was landing with a strong overspeed (350–370 km/h). Nevertheless, the captain managed to safely land and stop within the runway. 14 minutes have passed since the depressurization. All passengers were evacuated in 45 seconds.

As a result of the incident, 9 people died, who were pulled into a hole in the fuselage. Their bodies were never found. Many flight attendants received minor injuries, mostly during the evacuation process.

The investigation of the incident was complicated by the absence of the main piece of evidence - the tailgate. She fell into the Pacific Ocean. But the investigators found that earlier on the Boeing 747 there were cases of improper operation of the tailgate locks associated with violations during operation by the ground crew. In particular, several such cases took place on a damaged airliner shortly before the fatal flight. Therefore, initially the responsibility was assigned to the technical services of the airline.

However, when the door was nevertheless found at the bottom of the Pacific Ocean, this version was not confirmed. In addition, during this period there was a serious incident associated with the spontaneous opening of the tailgate on another 747th. A new investigation concluded that the likely cause of the accident was a short circuit in the electrical wiring and design flaws in the door. Because the Boeing 747-122's tailgate opened outward rather than inward, the pressure difference tended to push it out. There was a short in the wiring. The locking mechanisms began to spontaneously move towards the opening. At one point, the pressure knocked out the weakened mechanism and the tailgate. The latter, in turn, dragged along the parts of the fuselage to which it was attached.

After an investigation, the US National Transportation Safety Board recommended that all airlines replace the cargo door locks on Boeing 747-100 aircraft with stronger ones.

 The crew of the stricken liner received awards for their heroism.

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