Incident on a Boeing 737 MAX: we know how and why the door of an Alaska Airlines plane tore off in mid-flight

Le rapport d’enquête préliminaire de l’Agence de sécurité des transports (NTSB) a été publié ce mardi 6 février. ILLUSTRATION UNSPLASH – CODY FITZGERALD

The door of an Alaska Airlines Boeing came off in mid-flight on January 5, causing a few minor injuries. The preliminary investigation report, delivered this Tuesday, February 6, points to the absence of four bolts. 

The incident sent chills down our spine, and plunged Boeing into a crisis: on January 5 in Portland (United States), a door of a Alaska Airlaine's 737 MAX 9 suddenly broke away in mid-flight, at an altitude of 4,900 meters. 

Four bolts missing

According to the first conclusions of the investigation, released this Tuesday, February 6, bolts supposed to block the door of the device were missing. The Transportation Safety Agency (NTBS), in charge of the investigation, specifies that the absence of wear or deformation around certain holes "indicates that four bolts intended to prevent the cork holder from moving upward were missing before it moved" . 

These parts were apparently removed by Boeing employees during the inspection of the plane before its delivery last October.  This error occurred when several rivets, these small rods used to ensure the proper fixing of the plane's metal sheets together, had to be replaced during this intervention.

History of failure

Prior to the release of the NTSB report, Alaska Airlines had already reported '"poorly secured equipment& quot; after preliminary inspections. In recent months, Boeing has experienced other episodes of failure and has notably had to slow down its deliveries because of problems on the fuselage, in particular on the rear bulkhead of the aircraft. ;device.

The new boss of the American Civil Aviation Authority (FAA), Mile Whitaker declared during a congressional hearing this Tuesday 6 February that the agency planned to permanently post inspectors at Boeing production sites, believing that the "current system does not work", and reiterated the need for increased oversight of Boeing and its supplier Spirit AeroSystems, which manufactures the 737 fuselage. "I certainly agree that The current system does not work, because it does not provide safe devices. So we need to change that". 

Boeing has already grounded the 737 MAX for months in 2019 and 2020 after two deadly accidents which left a total of 346 dead.