https://www.bbc.co.uk/news/business-68220627
A door that blew away from a Boeing 737 Max shortly after take-off may not have been properly secured, a new report says.
The US National Transportation Safety Board has released initial findings from its probe into the incident on an Alaska Airlines plane in January.
It says four key bolts that were meant to lock the unused door to the fuselage appeared to be missing.
The incident happened minutes after Alaska Airlines Flight 1282 took off.
The missing bolts appeared to have allowed the door panel to move out of position and break away from the aircraft, the report says.
The panel covering an unused emergency exit - known as a door plug - blew out, leaving a gaping hole in the side of themain body of the aircraft, or the fuselage.
The door plug was manufactured by Boeing's supplier Spirit AeroSystems, and originally installed in the fuselage before being delivered to the aerospace giant.
According to the preliminary report, this door plug was later removed in the factory due to damage that had occurred during the production process.
Photographic evidence suggests that when the plug was reinstalled, at least three of the four locking bolts were not put back in place.
Spirit AeroSystems said it remain focused on working closely with Boeing and regulators "on continuous improvement in our processes and meeting the highest standards of safety, quality and reliability".
Damage to the door plug and its hinges, as well as a lack of damage to the areas where the bolts should have been, suggests that the bolts were missing before the door moved out of its normal position, the report said.
