Investigators say the Alaska Airlines incident apparently involved a door plug that had not been properly installed when it was delivered by the manufacturer.
A dramatic accident on an Alaska Airlines flight last month was apparently triggered by a door plug that had not been properly attached before the plane was delivered by Boeing, US investigators said on Tuesday.
Four bolts that acted as a fail-safe mechanism to hold a panel in place were not installed on the Boeing 737 Max 9, according to a preliminary report from the National Transportation Safety Board.
The incident has become the biggest crisis for Boeing since its entire fleet of Max aircraft was grounded worldwide in 2019 following two fatal crashes.
Max 9 planes with the same door configuration as the Alaska plane were grounded for weeks until they could be inspected, and regulators are poring over Boeing’s manufacturing processes and ratcheting up pressure on the company’s management.
The evidence from the recovered door and the fuselage indicate that the four bolts “were missing”, the NTSB report said.
The report reaches no conclusions about what caused the January 5 failure, but it is an unusually detailed account of the safety board’s initial fact gathering. It contains photos of the panel that later failed that were taken on the Boeing shop floor.
