Primary finding
Probable cause
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 necessary to ensure that manufacturing personnel could consistently and correctly comply with its parts removal process, which was intended to document and ensure that the securing bolts and hardware that were removed from the left MED plug to facilitate rework during the manufacturing process were reinstalled. Contributing to the accident was the Federal Aviation Administration’s ineffective compliance enforcement surveillance and audit planning activities, which failed to adequately identify and ensure that Boeing addressed the repetitive and systemic nonconformance issues associated with its parts removal process.
Investigator assessment
Analysis narrative
On January 5, 2024, about 1713 Pacific standard time, Alaska Airlines flight 1282, a Boeing 737-9 airplane, N704AL, experienced an in-flight separation of the left mid exit door plug and rapid depressurization during climb after takeoff from Portland International Airport, Portland, Oregon. One flight attendant and 7 passengers received minor injuries; the captain, the first officer, 3 flight attendants, and 164 passengers were uninjured; and the airplane sustained substantial damage. The scheduled domestic passenger flight was operated under Title 14 Code of Federal Regulations Part 121 and departed PDX about 1707 with a planned destination of Ontario International Airport, Ontario, California.