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Alaska Airlines 737-900 MAX loses a door in-flight out of PDX

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Old 7th Mar 2024, 12:30
  #1881 (permalink)  
 
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"NTSB, Boeing Spar Over Accident Probe Information"

Aviation Daily March 6 (verbatim):

"The NTSB’s frustration over not having documentation related to work done on a door plug that later blew off an Alaska Airlines Boeing 737-9 spotlights broader deficiencies within Boeing’s quality assurance process.

NTSB Chair Jennifer Homendy, testifying before the Senate Committee on Commerce, Science and Transportation March 6, said the agency is missing key details related to the aircraft involved in the Jan. 5 accident, despite multiple requests to Boeing.

Boeing has not provided us with the documents and information that we have requested numerous times over the past few months, specifically with respect to opening, closing, and removal of the door, and the team that does that work at the Renton facility,” she said.

Boeing took the rare step of commenting on a probe it is involved in, countering that it provided names of employees “early” in the probe, “including door specialists, who we believed would have relevant information.” It followed up by saying it provided the NTSB with a full list of all employees who work on 737 doors—even ones that did not work on the Alaska aircraft’s plug door—following Homendy’s testimony.

But detailed documentation will not be headed to NTSB because Boeing doesn’t have any. Sources with knowledge of the probe told Aviation Week that Boeing has provided all the paperwork that exists related to the mid-September 2023 rivet re-work during the aircraft’s production that required opening the plug. The work’s non-routine nature meant it was not documented in detail.

Boeing declined to comment on the Alaska door plug work specifically. “If the door plug removal was undocumented there would be no documentation to share,” the company said.

Part of Homendy’s testimony ran counter to Boeing’s version of events. Investigators have been told Boeing “can’t find” documents related to the door plug work, and names of employees that did the work “haven’t been provided,” she said.

She also said it is possible Boeing does not have the documents. “We’ve asked for the records with respect to what occurred,” she said. “Either they exist, and we don’t have them, or they do not exist.”

Investigators determined bolts needed to secure the plug in place were not installed when the accident flight, Alaska Flight 1282, departed. They apparently were not re-installed when the plug was removed as part of non-routine work on non-compliant fasteners done in Boeing’s Renton, Washington, 737 production facility. Understanding who did the work and why bolts were apparently not re-installed, and how Boeing’s follow-up inspections before the two-month-old airplane was delivered to Alaska in late October 2023, will be key to the NTSB’s probe.

NTSB investigators are interviewing Boeing and Spirit AeroSystems workers as well as contractors that might have relevant information, Homendy added. The interviews began on March 3 and are set to continue for several more days. She did not say whether the interviews are the first ones NTSB has done with 737 factory workers, or whether names on the list Boeing provided early on in the probe have been interviewed.

While Boeing may be cooperating by providing the information it has, the absence of documentation on a process critical to an in-service occurrence points to broad gaps in the company’s quality oversight process. A recent review by industry subject-matter experts found similar problems and issued more than 50 recommendations to address its findings.

The FAA has given Boeing until late May to address the report and an agency audit triggered by the Jan. 5 accident that also found substantial problems—including regulatory “non-compliance issues”—in the company’s production quality processes."

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Old 7th Mar 2024, 17:17
  #1882 (permalink)  
 
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Impressive ... NOT. Reputational damage must surely follow?
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Old 7th Mar 2024, 17:28
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Originally Posted by WillowRun 6-3
The work’s non-routine nature meant it was not documented in detail.
Gee, I always thought, when we were doing non-routine work, that it was especially important to document it in detail. And my systems, although certainly life-safety critical, weren't usually at risk of causing hundreds of people to fall out of the sky and die all at once.
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Old 7th Mar 2024, 18:25
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I came across these comments in another forum. I can not verify their accuracy as they are anonymous. But they do sound, to me at least, well informed.
They explain an interesting distinction between removing the door plug and opening the door plug to replace a seal and the different quality checks and record keeping that results:
Part 1: https://leehamnews.com/2024/01/15/un...comment-509962
Part 2: https://leehamnews.com/2024/01/15/un...comment-509963
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Old 7th Mar 2024, 18:32
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Originally Posted by OldnGrounded
Gee, I always thought, when we were doing non-routine work, that it was especially important to document it in detail. And my systems, although certainly life-safety critical, weren't usually at risk of causing hundreds of people to fall out of the sky and die all at once.
Let there be no doubt that what (apparently) happened here is far far outside the normal ‘professional international aerospace design and manufacturing standards envelope’.

From the context situation (new model, rates up and down, nightmare tail of uncompleted work, etc…) in which this work was done, you should expect not only more special and specific ‘paperwork’ but also special teams and measures to get everything properly done. This in spite of a degrading safety culture.

Paper is only part of the equation. Of equal interest are a host of IT-systems which contain specific and contextual information. And add to that a myriad of labels, stamps, signs, colours and more. Then of course talking to the various parties and people involved.

What surprised me, I posted about that earlier, is the rather bottom up approach the NTSB selected when it said it focused on the specific event and aircraft. Having been involved in numerous of such issues, my experience has been that a top down approach by 1-3 people (combining knowledge of airplane design, manufacturing design, tool engineering, configuration management, RFC/NCR, etc) worked faster and far more effective in such urgent and complex situations. And this event certainly is such a ‘situation’. In a number of cases with a top down you did not even need the ‘paper’ to know what clearly happened.

The delayed start of the NTSB may turn out to be detrimental to the talks and outcomes. Witnesses are witnesses…

An interesting statement by Boeing is using the words “doors and doors people” … I would not want to talk to them first but to others… which puts us in the field of aerospace definitions and (serious) consequences again.

A growing risk with this situation is that a future (Congressional/FAA) solution might contain rules that are aimed at specifically at Boeing and by their nature could hurt other aerospace manufacturers. This has happened in the past with engineering design issues.

Legally, Boeing like any company in NTSB cases shall freeze and then shall deliver information. I don’t know if the small focus NTSB start will hurt the effort to get the proper information.

In the case of MH370 it took a very long time to identify recovered debris items. Months instead of a few days. Since then I wonder about the performance of Boeing configuration management and tracking and tracing systems in manufacturing.

@Based on what I am reading of the March 6th Senate hearing … have to correct the above and add that the NTSB has changed its declared investigation approach and is now going much deeper and wider in both information, people and time.

Last edited by A0283; 7th Mar 2024 at 19:11.
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Old 7th Mar 2024, 23:34
  #1886 (permalink)  
 
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Understanding who did the work and why bolts were apparently not re-installed, and how Boeing’s follow-up inspections before the two-month-old airplane was delivered to Alaska in late October 2023, will be key to the NTSB’s probe
As reported in the Seattle Times, the NTSB investigation has revealed that a team of Boeing workers who specialize in servicing the door plugs on the assembly line in Seattle were assigned to enable three visiting contract workers engaged by Spirit Aerosystems to access and repair faulty rivets in the door plug area. When the plug was replaced after the rivet work was done, the Boeing team left out four critical bolts, causing the door to eventually work free and depart from the aircraft during a passenger flight at 16,000 feet.

In the past however, quality inspectors have alleged Boeing managers sometimes asked mechanics to fix defects but not record the repair work. This reduced the defect count, projecting a false sense of stability in the manufacturing work. In 2019, the Machinists union alleged this tactic was used to justify reducing the number of quality inspections.

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Old 7th Mar 2024, 23:48
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"As previously reported by The Seattle Times, Boeing employees opened the door plug to allow mechanics from supplier Spirit AeroSystems to fix some poorly installed rivets in the adjacent door frame. The Boeing mechanics then incorrectly reclosed it, leaving out four key retainer bolts that would have prevented the in-flight blowout."

I can't find this report. It seems like that guaranteed information would have been notable at the time.

From NTSB: "We know for a fact that there is a team that deals with the doors in Renton."

Yeah. But do they deal with the doors that are pre-installed by Spirit? Or do they only deal with all the exit doors that are installed in Renton?

If the coverage and those in charge could be a little less precise that would be great. Also, we need those TPS reports.

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Old 8th Mar 2024, 13:31
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Originally Posted by tsumini
Wondering what mechanics/engineers union legal or other requirements may have influenced plug/opening/closing procedures.
Alaska Airlines 737-900 MAX loses a door in-flight out of PDX permalink to Megan post

Quote”In the past however, quality inspectors have alleged Boeing managers sometimes asked mechanics to fix defects but not record the repair work. This reduced the defect count, projecting a false sense of stability in the manufacturing work. In 2019, the Machinists union alleged this tactic was used to justify reducing the number of quality inspections.”


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Old 9th Mar 2024, 01:59
  #1889 (permalink)  
 
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Does it get sadder or funnier? "An outside Boeing lobbyist on Capitol Hill sent an email to Republican members of Congress late Wednesday bluntly attempting to discredit the Senate testimony of National Transportation Safety Board Chair Jennifer Homendy. After The Seattle Times asked about the email Friday, both Boeing and the lobbyist scrambled to undo the potential damage."
https://www.seattletimes.com/busines...ntsb-testimony
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Old 9th Mar 2024, 05:34
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NTSB confirms door plug moved on prior flights

I dont think I've seen this mentioned yet... (sorry that I can't link since I'm new, but this was on CNBC.com and a couple other news sites)

"Homendy also confirmed that the Max 9 door plug had moved during prior flights, citing markings on the door. There were 154 prior flights by the Alaska Airlines Boeing 737 Max 9 before the Jan. 5 flight. “There were very small movements until it eventually came out,” Homendy said, adding that testing showed “you could see a bit of a gap towards the end” but that it was not clear how noticeable it was."
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Old 9th Mar 2024, 10:59
  #1891 (permalink)  
 
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Are we surprised? <<Boeing told U.S. Senator Maria Cantwell in a letter seen by Reuters that “we have looked extensively and have not found any such documentation” and the planemaker’s working hypothesis is “the documents required by our processes were not created when the door plug was opened.”>>
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Old 9th Mar 2024, 13:43
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No Door Plug Documents Found, Boeing Says

https://www.reuters.com/business/aer...20by%20Reuters.

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Old 9th Mar 2024, 20:15
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Any review of a process in fine detail normally has multiple routes to cross-identify something. There will be the report of whoever initially identified the problem. There will be a trail of who determined the fix, assigned the workers, parts issued from stores, completion records, etc. Given that Boeing supposedly has some of the most modern manufacturing and tracking procedures around, do the repair teams take before and after photographs of their work ? There will be payroll timesheets of those who did the work on the day. Plus a whole lot more. One might be missing. Are we saying that Boeing have NONE of this ? Even if someone went in and shredded them all right after the accident, where are the duplicates and computer backup records ?

And if none of this exists, can we even be certain that the door was removed and reinstalled at all ? Did the bolts get left off somewhere else ? Did Alaska work on it ? Did it come out from Spirit in Wichita like that ?
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Old 9th Mar 2024, 20:33
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Originally Posted by WHBM
Any review of a process in fine detail normally has multiple routes to cross-identify something. There will be the report of whoever initially identified the problem. There will be a trail of who determined the fix, assigned the workers, parts issued from stores, completion records, etc. Given that Boeing supposedly has some of the most modern manufacturing and tracking procedures around, do the repair teams take before and after photographs of their work ? There will be payroll timesheets of those who did the work on the day. Plus a whole lot more. One might be missing. Are we saying that Boeing have NONE of this ? Even if someone went in and shredded them all right after the accident, where are the duplicates and computer backup records ?

And if none of this exists, can we even be certain that the door was removed and reinstalled at all ? Did the bolts get left off somewhere else ? Did Alaska work on it ? Did it come out from Spirit in Wichita like that ?
Repeating myself her (multiple times), but I'm becoming increasingly convinced that someone used a sematic 'loophole', and said they were opening a door instead of removing a door plug. No paperwork required to open a door.
What needs investigation is why did someone do this - pressure from above, or a lazy mechanic. If it was as simple as someone being lazy to avoid the paperwork, I'd think termination would be in order (assuming of course they know who the responsible mechanic was).
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Old 9th Mar 2024, 20:36
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US Department of Justice has started an (criminal) investigation too !

This was already referred to by Ms Homendy in her testimony and answering questions of senator Cantwell last week.
If I understand that exchange correctly is was about the risk of another (ergo DoJ) investigation interfering with the NTSB investigation. And Ms Homendy staying that a risk was that people would stop speaking openly to the NTSB.

This was reported by the WSJ (behind paywall) this Saturday.
I can’t find a reference to this yet on the DoJ website.
Website www.nu.nl states that DoJ already contacted passengers and crew.







Last edited by A0283; 9th Mar 2024 at 20:53.
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Old 9th Mar 2024, 21:14
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Originally Posted by WHBM
And if none of this exists, can we even be certain that the door was removed and reinstalled at all ? Did the bolts get left off somewhere else ? Did Alaska work on it ? Did it come out from Spirit in Wichita like that ?
There are photos of the door with the bolts in place and the flags placed to indicate the rivets that needed to be reworked.

Unless you are being snarky - which I admit would also be justified. The lack of the bolts indicates the lack of a complete paper trail.

The starting point should be the workers who removed the defective rivets and put in the new ones. Those would be under Spirit's QA/QC system and should have some recollection about the door, though I expect they will say they don't recall, either because they are simply covering or the more reasonable cause - they do rivets all the time and this was not a particularly notable job. The outcome, months later was certainly notable, but a rivet is a rivet.

The riveters should have gone to their supervisor and said the door needed to be out of the way to do the rivet work, in which case the NTSB can follow the thread that direction. Or the riveters removed the bolts, intending to reinstall them and then that was delayed when the damaged seal was discovered and it snowballed from there.
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Old 10th Mar 2024, 06:17
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Originally Posted by WHBM
And if none of this exists, can we even be certain that the door was removed and reinstalled at all ? Did the bolts get left off somewhere else ? Did Alaska work on it ? Did it come out from Spirit in Wichita like that ?
Post #1758 has some of the actual photos.

Alaska Airlines 737-900 MAX loses a door in-flight out of PDX
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Old 10th Mar 2024, 13:37
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Originally Posted by WillowRun 6-3
Aviation Daily March 6 (verbatim):

"The NTSB’s frustration over not having documentation related to work done on a door plug that later blew off an Alaska Airlines Boeing 737-9 spotlights broader deficiencies within Boeing’s quality assurance process.

NTSB Chair Jennifer Homendy, testifying before the Senate Committee on Commerce, Science and Transportation March 6, said the agency is missing key details related to the aircraft involved in the Jan. 5 accident, despite multiple requests to Boeing.

Boeing has not provided us with the documents and information that we have requested numerous times over the past few months, specifically with respect to opening, closing, and removal of the door, and the team that does that work at the Renton facility,” she said.
Boeing's reply to that seems to be:

“Our team has shared multiple times with the NTSB that we have looked extensively and have not found any such documentation,” the letter said. “We likewise have shared with the NTSB what became our working hypothesis: that the documents required by our processes were not created when the door plug was opened. If that hypothesis is correct, there would be no documentation to produce.”

from https://www.ft.com/content/4463a386-...3-36f29b7376e4

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Old 10th Mar 2024, 23:28
  #1899 (permalink)  
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“There were very small movements until it eventually came out,”
Random, or all in one direction? The being "able to see a gap" loosely implies the latter.
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Old 11th Mar 2024, 07:55
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The long and short of it

The elephant in the room of course is why in Boeing's QA/QC system, contrary to "removal" of the door plug, the "opening" of the door plug doesn't require recording in Boeing's CMES (and therefore doesn't trigger a QC action), despite in both cases the removal and reinstallation of the four bolts is required. As most prominently highlighted in Leeham's news by "ThrowawayboeingN704AL" already on 16 Jan 24. The most likely answer is that after removal, it requires Boeing's "door team" to re-assure the correct rigging of the plug, while opening "just" requires to close it (and of course re-installing the four bolts).

Since CMES is the only authoritative Boeing building record, it's therefore not surprising that Boeing can't find any record of their own (see however below), because the "opening" of the door plug is not recorded there, since it wasn't required (but of course it should have been). And as a further consequence Boeing's "door team" hasn't been involved at all on this particular occasion. Only Boeing's "rivet" QC was involved in the recording of the defective rivets on 1 Sep 23 and subsequently on 19 Sep 23 it was them who stamped the rivet work according to specs and "complete" in CMES.

That doesn't mean that there's no record at all of "opening" the door plug. However, it's not in CMES, but in Spirit's SAT, the bulletin board used by Spirit (and its contractors) to coordinate "rework" actions at the Renton factory. So, probably, NTSB should be barking up Spirit's tree, not Boeing's. I'm pretty sure that both Boeing and NTSB are very well aware of that, as well as of the aforementioned elephant in the room.

The long and short of the ongoing reiterations between NTSB and Boeing about the official Boeing records boil down to the same question on the (non-)recording of opening versus removal, and therefore in a wider sense to Boeing's own QA/QC system. If by the end of this investigation process Boeing will not already itself have come up with a declaration that from now on both "opening" and "removal" of the door plug will be recorded in CMES (and in both cases will trigger QC), I'm pretty sure that the NTSB will include this in their safety recommendations in the final report. It's not by chance that the NTSB in its preliminary report notes that: "The investigation continues to determine what manufacturing documents were used to authorize the opening and closing of the left MED plug during the rivet rework."

Regards

Last edited by D Bru; 11th Mar 2024 at 08:43.
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