The National Transportation Safety Board’s (NTSB) ongoing hearing into the January in-flight failure of a Boeing 737 Max 9’s door plug has highlighted problems at Boeing’s Renton site, including concerns about employee training and pressure to complete work.
But testimony also reveals that many workers still view the culture at Renton as positive, citing a work environment characterised by teamwork, collaboration and dedication to safety.
That mixed picture came into view during a 7-8 August NTSB hearing in Washington, DC, part of the agency’s investigation into how and why Boeing in October 2023 delivered to Alaska Airlines a Max 9 with an unsecured left-side mid-cabin door plug.
That plug failed during a flight on 5 January, causing rapid depressurisation. The pilots safely landed the jet without serious injuries to passengers or crew.
During the two-day hearing, NTSB investigators questioned executives from Boeing and its top supplier Spirit AeroSystems, seeking information about what went wrong.
As the hearing opened, the NTSB released transcriptions of interviews held with numerous Boeing factory workers in Renton. Some workers painted a positive picture of the site’s culture.
“Everybody makes it feel comfortable here,” one line worker said. “Everybody helps out each other, and gives pointers to each other.”
“We all take pride,” said another. “These planes carry people… I fly. My family flies.”
Others expressed concerns, citing perceived pressure to complete work quickly, training deficiencies and the inexperience of many new employees hired by Boeing in recent years.
Boeing has insisted it has significantly strengthened its training regiment, including by beefing up both on-the-job instruction and the “foundational” training it provides to all new employees.
“It’s just push-push-push, push-push-push, push-push-push,” one worker told investigators.
“I just feel like the levels of knowledge and experience that we have differs, and I think that’s the hugest factor when it comes to how everyone operates,” said another.
Boeing has already taken responsibility for the 5 January door-plug failure, saying that during the jet’s assembly workers in Renton failed to install four bolts intended to secure the plug.
But the oversight is more complicated. Boeing rarely needs to remove door plugs during assembly, as the plugs arrive already installed in fuselages supplied by Spirit.
After the Alaska jet’s fuselage arrived at Renton on 31 August last year, Boeing discovered it contained five defective rivets. Spirit needed to fix the rivets, but to complete the work Boeing needed to remove the plug, which it did on 19 September. Critically, Boeing’s workers failed to document the removal.
With the rivet rework complete, a Boeing “move crew” on 19 September closed the jet’s doors – including the plug – and moved the aircraft outside the factory in preparation for delivery.
Because the removal had never been documented, Boeing neglected to reinstall the plug’s four bolts.
Testifying on 7 August, Boeing senior vice-president of quality Elizabeth Lund told investigators that following the 5 January accident Boeing transferred “two employees who were likely involved in the opening of the plug” off the production floor. Those workers have since, at their request, been placed on administrative leave.
However, Lund clarifies Boeing has not fully confirmed which employees were responsible for opening the plug, or exactly when they opened it.
Much of the hearing has focused on minute details about Boeing and Spirit’s quality processes. But testimony also reveals disagreement between Boeing and its largest labour union about the effectiveness of the company’s safety and quality assurance processes.
Boeing insists it has taken numerous steps to significantly strengthen those processes, including by implementing a safety management system and by encouraging staff to report concerns. Following the 5 January accident, Boeing also held company-wide safety training sessions.
But Lloyd Catlin, a representative for the International Association of Machinists (IAM), which represents some 33,000 Boeing workers, thinks much improvement is needed.
“We’ve never been impressed with Boeing’s training at all,” he tells investigators during the hearing. “Prior to January 5, Boeing’s training at their foundational training centre was in really bad shape.”
Catlin notes Boeing has made numerous changes to its quality and safety systems, creating confusion among workers.
“Boeing’s quality system is very complicated,” he says. “They have been through so many changes… that it is very ambiguous and open to interpretation.”
