SEATTLE — Embedded below is the National Transportation Safety Board's (NTSB) preliminary report into an incident where a door plug blew away from a 737 Max 9 jet at 16,000 feet, rapidly depressurizing the cabin and injuring seven passengers and one flight attendant.
The NTSB issued the report on Tuesday about what it has learned so far in the investigation. The agency still plans to interview employees with Boeing and Spirit AeroSystems, who manufactured the fuselage for the aerospace company.
The incident took place aboard flight 1282 operated by Alaska Airlines on Jan. 5. The plane took off from Portland, Ore., headed for Ontario, Calif. The jet was still climbing when the door plug detached from the fuselage.
The report indicates that four bolts intended to keep the door plug from moving vertically were not reattached to the plane after the plug underwent repair work at Boeing's Renton factory. A photo included in the report shows three places where the bolts were not attached. The fourth location where a bolt is supposed to be was obscured in the photo.
The NTSB was able to recover the missing door plug that fell off the 737 Max 9 jet from an Oregon man’s backyard. Investigators documented “contact damage” on several parts of the door plug, consistent with the part moving upward, outward and toward the tail of the plane. However, the holes where the bolts were intended to be were largely “intact and undamaged.”
A Non-Conformance Record generated at Boeing’s Renton factory documented a repair process in which the four bolts were removed to fix five damaged rivets on a section of the plane. Records show the repairs were made on Sept. 19, 2023 by Spirit AeroSystems personnel – employees of the company that manufactured the fuselage for Boeing.
There is no evidence that the door plug was ever opened again after the repair work was completed on the plane.