Boeing 737 Max in door panel blowout lacked four bolts, regulator says


Unlock the Editor’s Digest for free

A 737 Max jet left a Boeing factory missing four bolts designed to secure a door panel that blew off in mid-flight last month, according to a preliminary report by a US regulator.

The National Transportation Safety Board’s report on Tuesday is the first official account of how the door plug could have fallen out of the fuselage of an Alaska Airlines plane 16,000 feet over Oregon on January 5. The incident has raised questions about manufacturing and safety processes at Boeing and its supplier Spirit AeroSystems, which builds the Max fuselages.

The NTSB said that “four bolts that prevent upward movement of the [door] plug were missing” before the plug detached from the plane. 

According to the report, the fuselage arrived at Boeing’s factory in Renton, Washington, in late August 2023. An inspection there uncovered five damaged rivets adjacent to the door plug that later blew out.

In order for a team from Spirit to replace the rivets, the door plug was opened in September, according to the report. A photo shared via text message by Boeing employees after the rivet work showed the door plug later closed again without three of its bolts, while the location of the fourth bolt was obscured in the photo, according to the NTSB.

Dave Calhoun, Boeing chief executive, said in a statement responding to the report that “whatever final conclusions are reached, Boeing is accountable for what happened”.

“An event like this must not happen on an aeroplane that leaves our factory. We simply must do better for our customers and their passengers.”

Spirit said: “As we review the NTSB’s preliminary report, we remain focused on working closely with Boeing and our regulators on continuous improvement in our processes and meeting the highest standards of safety, quality and reliability.”

The blowout has intensified scrutiny at Boeing, which had been recovering from two fatal crashes of 737 Max aircraft in 2018 and 2019. The NTSB said its investigation was still in the process of determining what documents were used to authorise the opening and closing of the door plug during the rivet replacement.

Mike Whitaker, the new head of the Federal Aviation Administration, earlier on Tuesday told lawmakers in Washington that the regulator would put “more boots on the ground” to monitor the plane maker and review potential conflicts of interest associated with its long-standing delegation of some inspection and certification steps to Boeing.

The FAA is about halfway through an audit of Boeing and Spirit. Whitaker said the overall oversight approach needs to involve more direct surveillance of the companies. 

The FAA has 20 inspectors at Boeing and six at Spirit auditing the companies’ production and quality control practices. While the audit has not found anything requiring immediate action, the agency is shifting to an oversight approach involving more direct surveillance rather than just signing off on paperwork.

“Going forward, we will have more boots on the ground closely scrutinising and monitoring production and manufacturing activities” Whitaker told the hearing. The FAA would need more inspectors for aircraft certification, he said, and the regulator was likely to keep some in place at Boeing and Spirit facilities after the audit.

The FAA was “specifically” looking at the potential conflicts of interest that came with its long-standing delegation of some inspection and certification steps to Boeing. The agency had asked an outside group “to give us options on delegation and where we might bring in a third party, for example, in quality control, or quality assurance, to make sure you have a neutral set of eyes”.

Whitaker said the “current system is not working because it’s not delivering safe aircraft”. Boeing’s culture and incentives needed to be looked at, he said, because “if you don’t have that safety culture, I think it’s hard to make safe aeroplanes”.

Boeing has been accused by industry insiders and observers of prioritising its investors over safety considerations. “Regardless of their other motives, they’re not going to be able to build more aeroplanes until they meet those standards,” Whitaker said. The FAA has ordered Boeing not to expand its 737 Max production until it resolves its quality control issues.

The FAA chief also said he would meet chief executives of US airlines on Wednesday to discuss how to “share information more transparently and improve our safety management systems”.

Whitaker also encouraged Boeing employees to report safety concerns via an FAA hotline. “We will consider the full extent of our enforcement authority to ensure Boeing is held accountable for any non-compliance,” he added.

Earlier on Tuesday, Spirit said it would withhold its financial guidance for the coming year until there was “further clarity” on when the plane maker would be able to increase the rate at which it builds the aircraft.

Pat Shanahan, interim chief executive, said Spirit was taking a “hard look” at its processes following the Alaska incident.

A significant portion of the fuselage work was done manually, Shanahan told analysts. The answer for increasing the production quality of the 737 is “less manual [work], less interpretation, more inspections”, he said.