The Federal Aviation Administration has launched an audit into Boeing’s production system as part of its investigation into why an Alaska Airlines 737 Max 9’s emergency exit door plug failed during a flight last week.

The agency is also considering appointing an outside entity to oversee Boeing’s quality system and is reviewing the so-called “delegated authority” system over oversight.

Under the delegated authority process, the FAA grants Boeing and other aerospace manufacturers a large degree of autonomy in ensuring they comply with federal aviation regulations.

Boeing 737 Max at Renton site

Source: The Seattle Times, Ellen Banner, pool reports

A Boeing 737 Max destined for delivery to Alaska Airlines inside Boeing’s Renton final assembly site on 15 June 2022

“It is time to re-examine the delegation of authority and assess any associated safety risks,” FAA administrator Mike Whitaker said on 12 January. “The FAA is exploring the use of an independent third party to oversee Boeing’s inspections and its quality system.”

The FAA adds it has started “an audit involving the Boeing 737-9 Max production line and its suppliers to evaluate Boeing’s compliance with its approved quality procedures. The results of the FAA’s audit analysis will determine whether additional audits are necessary”.

The agency has also “increased monitoring of Boeing 737 Max 9 in-service events”.

Boeing did not immediately respond a request for comment.

The company, supplier Spirit AeroSystems and now the FAA’s processes are at the centre of investigations into the cause of the 5 January incident. Spirit supplies 737 fuselages.

The Alaska Max 9’s mid-cabin door plug – a plug covering an unused emergency exit – blew out shortly after the jet took off from Portland, leaving a massive hole in the side of the aircraft. The pilots landed safely and no passengers or crew suffered major injuries, but the event could have been much worse.

The FAA responded by grounding all Max 9s with the plugs, pending inspections. The order affects 171 aircraft globally. At least two airlines – Alaska and United Airlines – have already reported finding loose hardware related to the door plugs.

The circumstances suggest a quality problem on the part of Boeing, experts say.

“The grounding of the 737-9 and the multiple production-related issues identified in recent years require us to look at every option to reduce risk,” says the FAA’s Whitaker.

The FAA is investigating if the Alaska Airlines incident resulted from failures by Boeing in ensuring the jet conformed to its FAA-approved design, the agency has said. The US National Transportation Safety Board is also investigating, as are US lawmakers.

The FAA and its delegated-authority model, which has been used for decades, came under fire following two 737 Max crashes, in 2018 and 2019, which killed 346 people. Investigators attributed those crashes largely to a design problem involving the jets’ Maneuvering Characteristics Augmentation System – a flight-control system that placed both jets into dives from which the pilots could not recover.

In an 11 January letter to the FAA’s Whitaker, lawmaker Maria Cantwell, chair of the Senate Committee on Commerce, Science & Transportation, said the Alaska incident suggests “the FAA’s oversight processes have not been effective in ensuring that Boeing produces airplanes that are in condition for safe operation”.

Cantwell’s letter asks Whitaker to submit documents related to the FAA’s audits of Boeing and Spirit. The letter requests a response by 25 January.