As investigations continue into the Jan. 5 inflight loss of an exit door plug on an Alaska Airlines 737-9, the FAA has taken the extraordinary step of denying
Boeing permission to continue with its planned production increase of the twinjet.
The action, which comes as
Boeing is in the midst of ramping up 737 production at its Renton site as well as standing up a new assembly line in Everett, Washington, is part of a broader FAA reaction to the recent incident, which was triggered by a serious lapse in the manufacturer’s quality control processes.
In a Jan. 24 statement, the FAA says it “informed
Boeing it will not grant any production expansion of the MAX, including the 737-9 MAX. This action comes on top of the FAA’s investigation and ramped up oversight of
Boeing and its suppliers. The FAA today also approved a thorough inspection and maintenance process that must be performed on each of the grounded 171
Boeing 737-9 MAX aircraft. Upon successful completion, the aircraft will be eligible to return to service.”
The FAA’s action is a major blow to
Boeing’s plans to raise 737 MAX production beyond its current level of around 38 aircraft per month. The manufacturer ultimately aims to reach 50 aircraft per month by 2025/2026. The FAA’s move also casts a strong shadow over the final certification timeline of the final two MAX derivatives—the 737-7 and the stretched 737-10. Final approval for the -7 was thought to be imminent at the start of the year while type inspection authorization for the -10 was approved in November 2023.
Commenting on the agency’s hard line, FAA Administrator Mike Whitaker says that although he is confident the 737-9s can be inspected prior to returning to service, “this won’t be back to business as usual for
Boeing. We will not agree to any request from
Boeing for an expansion in production or approve additional production lines for the 737 MAX until we are satisfied that the quality control issues uncovered during this process are resolved.”
The FAA’s approved inspection and maintenance process will require an inspection of specific bolts, guide tracks, and fittings around the door plug as well as detailed visual inspections of left and right mid-cabin exit door plugs and “dozens” of associated components, says the agency. The inspection will also include retorquing fasteners and correcting any damage or abnormal conditions.
The FAA says the new instructions come after a review of data from 40 inspections of grounded aircraft. The FAA also convened a Corrective Action Review Board (CARB). The CARB, made up of safety experts, scrutinized and approved the inspection and maintenance process.
In a statement following FAA’s directive,
Boeing said, “We will continue to cooperate fully and transparently with the FAA and follow their direction as we take action to strengthen safety and quality at
Boeing. We will also work closely with our airline customers as they complete the required inspection procedures to safely return their 737-9 airplanes to service.”
Work Pauses
Boeing meanwhile says it will hold a series of “quality stand downs,” pausing work at factories and fabrication sites for sessions focused on quality and improvement. The first session will be held Jan. 25, with
Boeing’s 737 factory teams in Renton, Wash.
“Production, delivery and support efforts will pause for a day so teammates can take part in working sessions focused on quality,” a communication to
Boeing Commercial Airplanes (BCA) employees explains. “The sessions allow all teammates who touch the airplane to pause, evaluate what we’re doing, how we’re doing it, and make recommendations for improvement.”
As part of the safety effort, the “quality stand down” sessions will take place across all the company’s commercial aircraft factories and fabrication sites. Sessions will include “hands-on learning, reflection, and collaboration to identify where quality and compliance can be improved and create actionable plans that will be tracked to closure,” BCA detailed.
The work pauses come as the OEM faces scrutiny for its second MAX family grounding within a period of five years, in this instance stemming from the Jan. 5 737-9 Alaska Airlines door plug blowout. The incident, with no reported serious injuries, caused mandated and still-in-effect groundings for all -9s configured with the plug. Preliminary inspections by Alaska and United Airlines, the two U.S. airlines operating the variant, have confirmed finding loose hardware on some aircraft.
After the FAA announced its approved inspection process, United—the largest operator of the variant with 79—said it was
preparing aircraft to return to scheduled service beginning on Jan. 28. “We will only return each MAX 9 aircraft to service once this thorough inspection process is complete,” the airline said in a statement. Alaska, which has 65 MAX 9s in its fleet, now expects to bring its first few back into scheduled commercial service on Jan. 26, anticipating inspections to take up to 12 hours for each plane. “We expect inspections on all our 737-9 MAX to be completed over the next week,” Alaska said.
The FAA on Jan. 17
began reviewing data from 40 737-9 door plug assembly inspections conducted by Alaska and United. It is also investigating
Boeing’s manufacturing practices and production lines, with its top official describing “boots on the ground” manpower in a Jan. 23 update to CNBC.
“We’re shifting from more of an audit approach to a direct inspection approach,” FAA Administrator Mike Whitaker said in the interview. He did not rule out the possibility of additional external oversight, should the agency’s findings indicate a need for “a third party, a nonprofit technical organization, to provide a fresh set of eyes,” he told the news outlet.
“The safety of the flying public, not speed, will determine the timeline for returning these aircraft to service,” the agency has said.
Production Line Woes
According to a posting on a
Boeing employee forum by an unidentified individual, manufacturing quality problems concerning the Alaska Airlines 737-9, line number 8789, were unearthed on the Renton production line at the end of August 2023 and early September 2023 when an inspection discovered damaged or improperly installed rivets around the left-hand mid-exit door. Further investigations with Spirit AeroSystems—the supplier of the fuselage—revealed the pressure seal which plugs the gap between the door plug and the fuselage door frame was also damaged and needed to be replaced. To replace the pressure seal, the door plug had to be opened or removed, which would require the retaining bolts holding the panel in place be removed.
In the post, the employee alleges that—presumably owing to pressure to keep the production line flowing at pace—the line workers repaired the rivets and pressure seal but did not log the fact that the door had been opened or removed in the manufacturing process system. Logging the door removal in the system—known as CMES (common manufacturing execution system)—would have automatically triggered a quality assurance inspection that would have slowed production, but which would also almost certainly have discovered the retaining bolts were either missing or loose.
Boeing’s CMES is a software system that monitors, tracks, documents, and controls the process of manufacturing through the entire production life cycle. The company also uses a second system called SAT (shipside action tracker), which is a database used by assembly workers to investigate, monitor, and resolve any manufacturing build issues. According to the former employee, the sequence of events concerning the replacement of the rivets and seal was documented in the SAT, and the non-conformance issues noted in the CMES. However, neither of the systems subsequently flagged up the record of missing bolts or the need for verification, thereby revealing serious potential safety and build quality weaknesses with the monitoring systems.
According to information provided to Aviation Week, the aircraft involved in the incident, N704AL, made its first flight on Oct. 15, 2023, just 45 days after the issue with the left-hand mid-exit door was flagged in the factory inspection. The aircraft flew a second
Boeing production flight on Oct. 22, 2023, before making its first customer acceptance flight with Alaska five days later, and a second customer acceptance flight the following day. The delivery flight to Alaska took place Oct. 31, 2023.
Boeing’s recently announced quality stand down sessions are part of a multi-pronged improvement plan that includes an
independent review of its quality system and supplier oversight led by retired U.S. Navy Admiral Kirkland (Kirk) Donald. The OEM is also cooperating with ongoing FAA and NTSB investigations.
“We have let down our airline customers and are deeply sorry for the significant disruption to them, their employees and their passengers,” BCA President and CEO Stan Deal said Jan. 23. “We are taking action on a comprehensive plan to bring these airplanes safely back to service and to improve our quality and delivery performance.”
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