SEATTLE — The fuselage panel that blew off an Alaska Airlines jet earlier this month was removed for repair then reinstalled improperly by Boeing mechanics on the Renton final assembly line, a person familiar with the details of the work told The Seattle Times.
If verified by the National Transportation Safety Board investigation, this would leave Boeing primarily at fault for the accident, rather than its supplier Spirit AeroSystems, which originally installed the panel into the 737 MAX 9 fuselage in Wichita, Kan.
That panel, a door plug used to seal a hole in the fuselage sometimes used to accommodate an emergency exit, blew out of Alaska Airlines Flight 1282 as it climbed out of Portland on Jan. 5. The hair-raising incident drew fresh and sharp criticism of Boeing’s quality control systems and safety culture, which has been under the microscope since two fatal 737 MAX crashes five years ago.
Last week, an anonymous whistleblower — who appears to have access to Boeing’s manufacturing records of the work done assembling the specific Alaska Airlines jet that suffered the blowout — on an aviation website separately provided many additional details about how the door plug came to be removed and then mis-installed.
“The reason the door blew off is stated in black and white in Boeing’s own records,” the whistleblower wrote. “It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business.”
The self-described Boeing insider said company records show four bolts that prevent the door plug from sliding up off the door frame stop pads that take the pressurization loads in flight, “were not installed when Boeing delivered the airplane.” the whistleblower stated. “Our own records reflect this.”
NTSB investigators already publicly raised the possibility that the bolts had not been installed.
The account goes on to describe shocking lapses in Boeing’s quality control process in Renton.
The work of the mechanics on the door plug should have been formally inspected and signed off by a Boeing quality inspector.
It wasn’t, the whistleblower wrote, because of a process failure and the use of two separate systems to record what work was accomplished.
Boeing’s 737 production system is described as “a rambling, shambling, disaster waiting to happen.”
If that account of what happened is indeed fully documented in Boeing’s system it should be readily verified by the investigation.
The Seattle Times offered Boeing the opportunity to dispute the details in this story. Citing the ongoing investigation, Boeing declined to comment. Likewise, so did Spirit, the FAA, the Machinists union and the NTSB.
A convincing account
Passengers on Flight 1282 were traumatized when a door-sized section of the 737 MAX 9 fuselage exploded out 16,000 feet over Portland.
The door plug that blew out is a panel used to seal a fuselage cutout for an optional emergency exit door that is installed only by a few airlines with high-density seating. To a passenger seated at that location, it looks like just another cabin window.
The incident has proved a monumental setback for Boeing, drawing outrage and mockery across the world.
With large fleets of MAX 9 aircraft still grounded almost three weeks later, the chief executives of both Alaska and United on Tuesday sharply criticized Boeing.
“I’m more than frustrated and disappointed,” Alaska CEO Ben Minicucci told NBC News. “I am angry.”
It was clear soon after the incident that the plug must have been mis-installed.
When the cabin is pressurized, six small stop fittings on either side of the plug press against corresponding stop pads on the door frame.
The only way for the plug to have blown out is if it moved up, so that the stop fittings were no longer aligned with the stop pads — which is how the plug is opened for maintenance.
Four key bolts that prevent such upward movement in flight could not have been in place.
The anonymous whistleblower posted his account online, in the comments appended to an article about the door plug incident on the Leeham.net aviation website.
Before explaining what happened, the person states the motivation for posting it. Doing so, the whistleblower repeated complaints frequently offered by Boeing longtimers who contend the company’s 1997 acquisition of competitor McDonnell Douglas undercut the Boeing’s focus on quality.
“There are many cultures at Boeing, and while the executive culture may be thoroughly compromised since we were bought by [McDonnell Douglas], there are many other people who still push for a quality product with cutting edge design,” the whistleblower wrote. “My hope is that this is the wake up call that finally forces the Board to take decisive action, and remove the executives that are resisting the necessary cultural changes.”
The Seattle Times does not know the identity of the whistleblower.
However, the details provided about the manufacturing process failures that led to the door plug blowout appear authentic and authoritative. The Seattle Times confirmed with a Renton mechanic and a former 737 MAX production line manager that the whistleblower’s description of how this kind of rework is performed and by whom is accurate.
The Times also confirmed that the whistleblower accurately described the computer systems Boeing uses to record and track 737 assembly work, systems that mechanics and engineers sign into every day when they begin work.
The whistleblower outlines how, because of a mistake, the removal and re-installation of the door plug in Renton was never entered in the computer system where every detail of the build process on each individual aircraft is recorded. As a result, no quality inspection was triggered.
Ed Pierson, a former manager of the MAX production line and himself a whistleblower who raised concerns about quality control in Renton before the first MAX crash in Indonesia in 2018, said in an interview Monday the new account of the door plug mis-installation and the error in the recording of the work “is very consistent with what I saw in the factory personally.”
After reading the whistleblower account, he said “I think there is a very high probability this is accurate.”
“People, when they’re pressured and rushed, they think, well, I’ll catch up on the paperwork later,” Pierson said. “Then it goes from shift to shift and you don’t know if the next shift got it or not.”
As the whistleblower describes, many routine fixes are done by a team of mechanics from Spirit who are permanently on site in Renton to do “warranty” repairs on parts built by Spirit in Wichita.
Pierson confirmed that Spirit employees were stationed in Renton doing this kind of rework as far back as 2018.
“We had Spirit employees in our factory when the fuselage came in that were doing what people call ‘warranty work,’ but we would just call it defects or non-conformances,” Pierson said.
The records show a Spirit team did initial work on the door plug that later failed.
But the aviation insider familiar with the details of the work, who asked for anonymity because of the sensitivity of the NTSB investigation, said it was Boeing who opened the plug and then closed it up, marking the job complete.
How the quality process failed
The online whistleblower described two systems Boeing uses to track the thousands of jobs performed to assemble each aircraft. The mistake occurred when a job was discussed in one system but not fully entered in the other.
The first system, the formal record for the FAA of every job completed in the building of the airplane, is called the Common Manufacturing Execution System or CMES — pronounced “sea-mass” by the mechanics.
The other system, called the Situation Action Tracker or SAT, is an informal Boeing factory messaging board used by mechanics, engineers and management to flag issues.
The Renton mechanic, who asked not to be named to protect his job because he spoke without company permission, said he uses SAT when a defect shows up “to bring more eyes on what the problem is” and get it addressed.
If nothing is amiss, there’s no need for Boeing to do anything more than visually check the door plug, which is fully installed in the fuselage when it arrives in Renton by train from Wichita. Opening it up is not normal procedure.
However, the whistleblower states that Spirit produces “a hideously high and very alarming number” of defects.
The whistleblower says Boeing’s records for just the past year document a total of 392 nonconforming findings at the location where the door plug is installed, including both MAXs with actual emergency doors there and those like the Alaska jet with permanent plugs.
That doesn’t mean such faults were found on 392 MAXs. Ten loose rivets on a single door plug would be 10 non-conformities. Still, it’s not a reassuring number.
On the jet that would become Alaska Airlines Flight 1282, mechanics found problems in the door plugs on both sides of the airplane.
The whistleblower, confirming a previous report, says that on Aug. 31 mechanics found discrepancies on the door plug on the right side of the airplane, not the one on the left that was to blow out.
The following day, a different team of mechanics found “damaged and improperly installed rivets” on the left door plug. The whistleblower says this defect was written up in both CMES and SAT.
The SAT message thread shows the Spirit team repaired the rivets and sent it back to a Boeing quality inspector.
At this point, the whistleblower says the process began to go badly wrong.
The Boeing inspector recorded in CMES that the repair was not done properly, that the Spirit team “just painted over the defects.” As a result, the repair job was reopened.
Looking at it anew, the Spirit mechanics then discovered that, in addition to the problematic rivets, the pressure seal sandwiched between the plug and the airframe was damaged and needed replaced.
“The big deal with this seal,” the whistleblower wrote, was that the replacement part was not on hand in Renton and needed to be ordered, which could threaten to delay the jet’s delivery schedule.
Plug removal isn’t logged in the system
That elevates the repair to more urgency.
The whistleblower cited an entry in the SAT system showing the Boeing and Spirit teams discussed whether the door plug would have to be removed entirely, or just opened.
Critically, says the whistleblower, removal of the door plug has to be recorded in CMES and after it is re-installed requires a formal sign-off from a quality inspector that it’s been done properly and that the airplane complies with regulatory requirements.
But regardless of whether the plug is just opened out on the bottom hinge or fully removed, to do so the four bolts have to be taken out so the plug can be moved upward a few inches, above the stop pads.
“A removal should be written in either case” and a quality inspector required to verify install, the whistleblower wrote.
Instead, someone decided that the door only needed to be opened and a formal Removal entry in CMES was not required — and hence no inspection.
The whistleblower labels this “a major process failure.”
In short, the crucial bolts were removed and no one inspected the plug afterward to ensure they were reinserted.
The published whistleblower account does not explicitly state who removed and reinstalled the door plug in Renton.
The information that it was Boeing mechanics who removed the plug is from a different source with knowledge of the repair, the person who cannot be identified because of the sensitivity of the ongoing investigation.
The online whistleblower writes that the entire sequence of the work is documented in SAT and the damaged rivets and pressure seal are recorded in CMES.
However, there is no mention in CMES of a removal and reinstallation, even though that had to happen to replace the seal sandwiched between door plug and airframe.
Nor is there “any record of removed retention bolts” even though it’s physically impossible to open or remove the plug if those four bolts are in place.
The critical procedural error, the lack of proper recording of the work done and what still needed to be done for completion, seems to reflect what former MAX assembly manager Pierson calls the “manufacturing chaos” he witnessed first hand in 2018 when mechanics were pushed to accelerate work to meet schedule.
“If a mechanic on day shift removes the part and doesn’t fill it out properly and doesn’t document it properly, and then another comes in on second shift that doesn’t know it,” Pierson said “The first person not connecting with the second person, this is how these things happen.”
Aside from the quality control process failures, Boeing employees see the labor turnover during the COVID-19 pandemic as a significant factor.
The Renton mechanic, a veteran machinist, lamented that wage competition means Boeing is having trouble hiring employees to replace all the experienced people who left during the pandemic.
Another mechanic, who also asked not to be identified to protect his job, echoed that, saying that new people “with very little to no experience working on this type of aircraft” have been hired to replace machinists with over 20 years experience.
At the end of his online post, the whistleblower asks “So, where are the bolts?” then offers a guess:
“Probably sitting forgotten and unlabeled … on a work-in-progress bench. Unless someone already tossed them in the scrap bin to tidy up.”
