The National Transportation Safety Board has found the probable cause for last year’s Alaska Airlines door plug blowout was Boeing’s failure to “provide adequate training, guidance, and oversight” to its factory workers.
An NTSB news release published Tuesday stated the organization also found the Federal Aviation Administration wasn’t effective in making sure Boeing addressed “repetitive and systemic” nonconformance issues when removing parts.
Additionally, the NTSB stated that Boeing’s voluntary safety management system was inadequate and lacked formal FAA oversight two years prior to the accident.
“The investigation found that accurate and ongoing data about overall safety culture is necessary for an SMS to be successfully integrated into a quality management system,” the release said.
Alaska Airlines flight 1282 was climbing through 14,830 feet on Jan. 5, 2024, when the left middle-exit door plug separated from the plane six minutes after takeoff. The door plug of the Boeing 737 MAX 9 was later found in a Portland-area school teacher’s back yard.
No one was killed during the incident, though several passengers later sued Alaska Airlines and Boeing for injuries sustained during the flight.
‘Safety Deficiencies’
Tuesday’s NTSB report stated that rapid depressurization in the cabin caused some passengers’ belongings to be sucked out of the airplane. The door to the flight deck swung open and injured a flight attendant, and seven other passengers were also injured.
“The safety deficiencies that led to this accident should have been evident to Boeing and to the FAA — should have been preventable,” NTSB Chairwoman Jennifer Homendy said in the release. “This time, it was missing bolts securing the MED plug. But the same safety deficiencies that led to this accident could just as easily have led to other manufacturing quality escapes and, perhaps, other accidents.”
NTSB investigators found that the unbolted plug “had moved incrementally upward during previous flight cycles” until separating from the airplane during the flight.
The airplane – which was delivered to Alaska Airlines three months prior to the incident – had its door plug opened without required documentation in Boeing’s Renton, Washington, factory on Sept. 18, 2023, to perform rivet repair work on the fuselage.
Though Boeing procedures called for specific technicians to open or close MED plugs, none of those workers were working when it was closed the following day.
“The absence of proper documentation of the door plug work meant no quality assurance inspection of the plug closure occurred,” the NTSB release said.
The findings have led the NTSB to issue 11 new safety recommendations to the FAA and seven to Boeing, which can be read here. The NTSB stated that a final report will be published “in the coming weeks” on ntsb.gov.
