Alaska Airlines 1282 Door blows out at 16000 feet | Full ATC Audio & Phone Tapes

January 5, 2024 — Alaska Airlines Flight 1282, Boeing 737 MAX 9 — Portland

Alaska Airlines Flight 1282 was climbing out of Portland when the left mid-exit door plug separated from the fuselage. The cabin depressurized rapidly. The crew declared an emergency and returned to Portland. The investigation later traced the physical separation to missing retaining bolts and failures in Boeing's manufacturing and quality-control processes.

Four missing bolts explained the door-plug separation

The final NTSB investigation examined the recovered door plug, the surrounding fuselage structure and Boeing's manufacturing records. Investigators determined that four bolts intended to prevent upward movement of the plug were missing before the accident flight.

The plug had been opened at Boeing's Renton factory to permit rivet-repair work. The parts-removal process was not properly documented, and the closure did not receive the quality-assurance verification that the procedure was designed to provide. Investigators also found that personnel experienced with opening and closing the plug were not working when the plug was closed.

The NTSB found that the unsecured plug moved upward incrementally during previous pressurization cycles. That movement was not readily detectable during a normal preflight inspection. On Flight 1282, the plug moved far enough to disengage from its fittings and separate, producing rapid depressurization and damage to the surrounding fuselage and cabin.

The Board's final investigation assigned probable cause to Boeing's inadequate training, guidance and oversight of manufacturing personnel. Ineffective FAA compliance surveillance and planning was identified as a contributing factor. The investigation also produced extensive safety recommendations.

Investigators also reconstructed what happened inside the cabin. The opening caused personal belongings to leave the airplane, oxygen masks to deploy and the cockpit door to open. A flight attendant was injured, as were seven passengers. The door plug and several cabin components were recovered along the flight path. The investigation then followed the hardware backward into manufacturing records, where the missing securing bolts and undocumented rework were identified. The significance of the final report is that the immediate structural separation was only the visible end of a longer manufacturing-control failure.

The investigation also examined issues beyond the missing bolts. The final report addressed cockpit voice recorder duration, child restraint systems and FAA oversight, among other matters. Those recommendations came from the Board's review of the accident and its broader safety implications. The immediate event, however, remains tightly defined: the door plug separated because the retaining hardware was not properly restored during manufacturing rework.

“The National Transportation Safety Board determines that the probable cause of this accident was the in-flight separation of the left mid exit door (MED) plug due to Boeing Commercial Airplanes failure to provide adequate training, guidance, and oversight”

Accident Facts

Timeline

Sources