Boeing 737 Max 9 in Alaska Airlines mid-air blowout was missing bolts, US probe finds
- Investigators say the dramatic incident apparently involved a door plug that had not been properly installed when it was delivered by the manufacturer
- A panel on the left side of plane blew open shortly after take-off, causing the aircraft to lose pressure and subjecting passengers and crew to high winds
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.