Workers at Boeing’s final assembly line in Renton reportedly removed and reinstalled the door plug that slipped off the Alaska Airlines 737 MAX 9 on January 5.
The claim came from an anonymous whistleblower who posted a comment on Leeham News on January 16. Another person familiar with the details of the assembly line reported something similar to The Seattle Times on January 24.
Until then, the main suspicions fell on Spirit Aerosystems, a Boeing supplier that assembled the 737 MAX fuselage, including the installation of the door plug, a part that replaces the emergency exit in cabins with fewer seats.
According to what the two outlets described, the jet registration N704AL had flaws noted in the installation of the doors by a Boeing quality team, however, the lack of a safe verification process would have allowed the work to go unnoticed.
The most likely hypothesis indicates that the plug was removed and then reassembled without four bolts securing it to the fuselage. The NTSB (National Transport Safety Board) is investigating the incident, but has not yet reached conclusions.
Unsafe quality process
According to The Seattle Times, Boeing, Spirit, FAA and NTSB declined to comment on the allegations, saying the investigation is ongoing.
“The reason the door blew off is stated in black and white in Boeing’s own records,” the whistleblower wrote to The Leeham News. “It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business.”
According to him, the volume of failures found in the structures assembled by Spirit is shocking, but Boeing does not have a safe quality process capable of guaranteeing that the aircraft were completely checked after repairs carried out by Spirit, which maintains a team in Renton for this purpose.
One of the reasons would be the use of two systems for recording work performed, but which are not connected.
Day of reflection
Amid the allegations, Boeing will pause the Renton assembly line on January 25 to “evaluate what we’re doing, how we’re doing it and make recommendations for improvement,” said Boeing Commercial Airplanes President Stan Deal.
During the stand down, employees will participate in quality workshops. Boeing said more pauses will occur over the next few weeks.