The fuselages “have been gone over with a microscope in light of what we’ve experienced here in the last four months,” Boeing chief executive David Calhoun assured analysts that same month.
Then came Friday’s accident, when a door plug partway down the plane blew out, leaving a gaping hole beside a row of seats and forcing an emergency landing. On Saturday, the Federal Aviation Administration ordered the grounding of all Boeing 737-9 Max planes with the same part — 171 in total — for inspection.
The National Transportation Safety Board is only starting its investigation into the causes of the breach. But experts say initial evidence points to an issue with the door plug in question, which is used to block an optional emergency exit on the 737 Max 9 — raising fresh questions about issues in Boeing’s supply chain.
The troubled history of the Max means a fresh incident like Friday’s is going to prompt renewed scrutiny on both the safety record and the company’s transparency, said Dennis Tajer, a spokesman for the Allied Pilots Association, which represents crews at American Airlines.
“We are compelled to ask: What else is there?” Tajer said. “In the past, when you’ve hidden things, we’re compelled to say we don’t believe you. Tell me more.”
Boeing’s reputation took a heavy blow during the worldwide grounding of an earlier model of the Max after two crashes in 2018 and 2019 that killed 346 people. Investigations revealed problems with the design of an automated system on the plane, which had not been fully disclosed to the FAA.
The crashes shook confidence in both Boeing and the FAA. And while those planes were cleared again as safe to fly in 2020, the process of rebuilding trust has been a long one. Now, the latest incident comes as Boeing is under pressure to deliver more 737s as airlines ratchet up their orders, spurred by the rebound in air travel after the coronavirus pandemic.
Boeing declined to comment Sunday on the recent production issues.
Eyes on Spirit AeroSystems
The FAA acted quickly after the Alaska incident, issuing an emergency directive that warned an apparent problem with the plug could lead to the door hitting the airplane and causing pilots to lose control. Alaska and United, the other major U.S. operator of the Max 9, are working with regulators to conduct inspections and take any corrective action before putting the planes back in the air.
It remained unclear Sunday exactly what the FAA would require before the planes could fly again. The agency said in a statement “they will remain grounded until the FAA is satisfied that they are safe.”
Alaska had canceled 163 flights as of Sunday afternoon, about a fifth of its schedule, according to data from FlightAware. United had canceled 240 flights, 9 percent of its schedule.
The accident unfolded shortly after the plane had departed from Portland for Ontario, Calif. The NTSB said no one was sitting in the seat closest to the breach, but it noted after the accident that the headrests of two seats and the back of one were missing. Several passengers were injured, Alaska said, but all had been “medically cleared” by late Saturday evening.
NTSB investigators, accompanied by board chair Jennifer Homendy, arrived in Portland on Saturday afternoon to begin their investigation. Homendy suggested nothing is off the table in the probe, including the issue of the plane’s manufacturing.
The NTSB has asked for the help of the public and law enforcement to recover missing parts of the plane. Finding the panel that broke off will be an important task for investigators, according to Robert Mann, an aviation consultant. But the relatively clean appearance of the break suggests a manufacturing issue with Boeing supplier Spirit AeroSystems — a problem that went undetected for the several weeks that the new plane had been in service.
“Hopefully, an isolated issue, nonetheless troubling,” Mann said in an email.
Over the past year, Spirit AeroSystems has been linked to other issues affecting the production of Max jets. In April, Boeing notified regulators of a problem with fittings at the rear of the plane’s fuselages, and in August, it disclosed that a set of holes on a rear bulkhead had been improperly drilled. In both cases, the FAA said there was no immediate safety concern.
But in October, Spirit AeroSystems replaced its chief executive, installing Boeing veteran and former Deputy Defense Secretary Patrick Shanahan to hold the post on an interim basis. Later the same month, Spirit AeroSystems and Boeing announced a plan to work more closely together to improve quality, which Shanahan said at the time would mean the companies working “shoulder to shoulder to mitigate today’s operational challenges.”
On Saturday, Spirit AeroSystems confirmed that it had installed the door plug — which is used to block a space for an emergency exit that is only required by operators that pack a large number of seats onto the Max 9 — on the Alaska plane. The company declined to comment further Sunday.
As for the manufacturing issues raised in 2023, Calhoun, the Boeing chief executive, told analysts in October that these were not a sign that the company’s recovery was faltering.
“We’ve added rigor around our quality processes,” he said at the time. “We’ve worked hard to instill a culture of speaking up and transparently bringing forward any issue — no matter the size — so that we can get things right for a bright future.”
Beyond the door plug, other problems have cropped up. In December, the FAA said it was monitoring inspections for loose bolts in the rudder control system on some Max aircraft. Boeing recommended the inspections after an overseas airline discovered a bolt with a missing nut, while Boeing found an undelivered aircraft with an improperly tightened nut. The FAA said Sunday that no other instances of the issue have been reported.
In August, the FAA issued a directive saying that in some conditions, the anti-ice system on Max engines could overheat if left running for more than five minutes. That could cause the engine to break apart, putting passengers sitting behind the wing in danger and potentially forcing the plane to make an emergency landing away from an airport.
Meanwhile, last month Boeing sought a two-year exemption from FAA safety rules to give it more time to rework the system as it develops a future, smaller model of the Max, whose design is still under safety review by regulators. The fix would also be applied to older versions of the Max, Boeing said in its application. The FAA said Sunday it would review any public comments on the application and had not set a timetable for making a decision.
That problem is deeply troubling to pilots and a sign of ongoing problems with the new jets, Tajer warned.
“We have a Max that continues to have engineering struggles with the other models and now we have … the grounding of the Max 9, which has structurally come apart,” Tajer said. “I don’t think you have to be a pilot to realize there’s a problem within Boeing on this airplane.”
