Four bolts used to secure the panel that ultimately blew up an Alaska Airlines plane during a flight last month were removed — and do not appear to have been replaced — at Boeing’s factory in Renton, Washington, according to a preliminary report released on Tuesday by the National Transportation Safety Board.
The panel, known as a door plug, was opened to repair damaged rivets in the plane’s fuselage, according to Boeing records. The report did not say who removed the bolts holding the door plug in place. However, the safety panel said it appears that not all of the bolts were put back when the door was put back on the plane after the rivets were repaired.
As evidence, the NTSB provided a photo of the door plug after it was reinstalled, but before the interior was restored. In the picture, three of the four bolts appear to be missing. The location of the fourth bolt is covered with insulation.
The report said the image was attached to “a text message between Boeing team members on September 19, 2023.” Boeing employees were “discussing the internal recovery after completing rivet processing during the second shift that day,” the report said.
The safety board said there was no evidence the plug was reopened after it left the Boeing factory. The plane was delivered to Alaska Airlines in late October.
The report increases scrutiny of Boeing, which has been trying for weeks to contain the fallout from the incident, and raises new questions about whether the company did enough to improve safety after two fatal crashes of 737 Max 8 planes in 2018. and 2019. It also answers critical questions about why the door plug detached shortly after Alaska Airlines Flight 1282 took off from Portland International Airport in Oregon.
In a statement, Dave Calhoun, Boeing’s chief executive, said: “Whatever the final conclusions, Boeing is responsible for what happened.”
“An event like this should not happen on an airplane leaving our factory,” he added. “We just have to do better for our customers and their passengers. We are implementing a comprehensive plan to enhance quality and the trust of our stakeholders.”
The NTSB eliminated other possible reasons for the improper installation of the door plug. The part was manufactured in Malaysia in March and received by Spirit AeroSystems, a Boeing supplier in Wichita, Kan., that makes Max fuselages, in May, the report said. While the safety panel said Spirit had identified a minor problem with the “seal flush” of the door plug, the report found that the problem did not require further manufacturing work and that Spirit had not indicated any other quality alerts for the plug.
Joe Buccino, a spokesman for Spirit, said: “We remain committed to working closely with Boeing and our regulators to continually improve our processes and meet the highest standards of safety, quality and reliability.”
The fuselage was then shipped to Boeing on Aug. 20, arriving at the Renton plant on Aug. 31, the report said. There, the damaged rivets – which are often used to join and fasten parts on airplanes – were spotted on September 1. Once the plug was removed to access the rivets, employees at Spirit AeroSystems in Renton completed the repairs.
After the plane was delivered to Alaska Airlines, wireless Internet equipment was also installed in Oklahoma City from November 27 to December 7. But the contractor doing that work, AAR, said it had “modified about 60” Alaska Airlines 737 Max 9 planes and didn’t have to remove any door plugs to do the job, according to the report.
The safety board said its investigation would continue to look at what documents had been used “to authorize the opening and closing” of the door stopper.
Almost immediately, the Alaska Airlines incident prompted the Federal Aviation Administration to ground some Max 9 aircraft, snarling flight schedules for days at Alaska and United Airlines, the two US carriers that fly the model.
“This incident should never have happened and cannot happen again,” the FAA said in a statement Tuesday after the safety board’s report was released.
The FAA has also indefinitely curtailed Boeing’s ambitious plans to ramp up production of all Max jets, plunging the company into uncertainty. The company had planned to produce 42 jets a month this year and 50 a month next year, but instead it will remain flat at 38, possibly for many months. Boeing executives declined last week to provide a financial forecast for the year, citing the incident and the need to focus on safety.
Furious airline executives have taken the rare step of publicly criticizing Boeing and expressing doubts that it will be able to deliver the planes they ordered on time.
The incident and its ripples have plunged Boeing, one of the world’s two largest plane makers, into a familiar position: trying to navigate a crisis with unknown financial and reputational costs. Just five years ago, after two Max 8 crashes that killed nearly 350 people, the company spent billions of dollars to make its planes safer and repair its reputation. These crashes were caused by a defect in the aircraft’s flight stabilization system.
With Boeing back on its heels, it is struggling to reassure customers, regulators and members of Congress that its focus is squarely on improving quality control. Mr. Calhoun visited the Spirit in Wichita. Boeing also held an event in which workers at the Renton plant took a day off from work to attend quality sessions. And he has vowed to reward employees “for speaking up to slow things down, if that’s what it takes.”
Jeff Guzzetti, a former safety board and FAA accident investigator, said Boeing had to make significant changes, including shifting from financial performance to safety.
“Given the totality of Boeing’s recent problems, starting with the two 737 Max accidents, and continuing into the production problems of other Boeing models, this report adds another straw to the camel’s back,” he said. “I don’t think Boeing can take any more straws. They know this, and so does the FAA.”
But even as it tries to solve its problems, Boeing said on Sunday that a supplier last week had found a new problem with the fuselages on dozens of unfinished 737 Max planes. The supplier found that “two holes may not have been drilled exactly to our requirements.”
While not naming the supplier, a Spirit spokesman said a member of its team identified an issue last week that did not meet engineering standards. Boeing said the problem will force Boeing to rework about 50 planes, delaying their delivery.
In a call with analysts on Tuesday, Spirit AeroSystems CEO Patrick Shanahan said he was increasing the number of inspections he was conducting, along with Boeing’s.
Also Tuesday, Mike Whittaker, the FAA’s top official, told a House panel that the agency will step up its presence on the ground monitoring Boeing’s aircraft production.
“In the future, we will have more boots on the ground scrutinizing and closely monitoring production and manufacturing activities,” Mr Whitaker told the Transport and Infrastructure Committee’s Aviation Subcommittee.
In addition to limiting Boeing’s production growth, the agency opened an investigation into the plane maker’s compliance with safety standards. It also launched a review of the company’s production of Max, which Mr Whitaker said would take six weeks.
He said the agency had deployed about a dozen inspectors to Boeing and about half a dozen to Spirit.
Sadul Nerkar contributed to the report.
