An investigation by the Transportation Safety Agency (NTSB) into an incident involving an Alaska Airlines Boeing 737 MAX 9 has revealed that the aircraft’s door, which tore off mid-flight, was missing bolts. The aircraft, which was carrying 174 passengers, had to make an emergency landing due to this incident.
The NTSB’s investigation found that the absence of wear or deformation around certain holes indicated that four bolts, which were supposed to prevent the cap holder from moving upward, were missing before the incident happened.
A resident of Portland, Oregon, discovered the door of the aircraft in his garden just after the incident. The plane was initially headed to Ontario, California but had to return back. The 171 passengers and 6 crew members onboard were at an altitude of 5,000m when the incident occurred, causing only minor injuries.
A video taken during the incident showed that the door was torn off due to poorly screwed bolts on the Boeing 737 Max.
In its report, the NTSB included documents and photos showing that Boeing employees had removed the four bolts during an inspection before the plane’s delivery. The bolts were removed to replace five damaged rivets in the cabin of the aircraft, but photos taken after changing the rivets show that the bolts were not reinstalled.
The door was used to block an exit and was not meant to be opened, as the model already had enough emergency exits. Alaska had reported “loose equipment” after conducting preliminary inspections even before the NTSB report was released.
United Airlines, which owns the largest fleet of 737 MAX 9s (79 aircraft), reported finding “bolts that needed to be tightened” during their checks.
Boeing has had other incidents of failure recently, including problems with the aircraft’s fuselage that caused a slowdown in its deliveries. Moreover, two crashes of the same model in 2018 and 2019 resulted in 346 deaths.
The new head of the American civil aviation regulatory agency (FAA), Mike Whitaker, has expressed concerns over unresolved issues with Boeing and underlined the need for stricter supervision to address these issues.