A door that blew away from a Boeing 737 Max may not have been properly secured, a new report says.
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 2182 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 the main tube of the aircraft – known as the fuselage.
It happened just moments after the flight took off from Portland International Airport.
The plane then suffered a rapid loss of cabin pressure, as air rushed out and the atmosphere within the plane equalised with the thinner air outside.
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 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.
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.