Anon Boeing engineer reveals why the 737 door blew off
leehamnews.com
leehamnews.com
I guess that's why it doesn't immediately fall out.
Has anyone seen mechanical or assembly drawings of these things?
I guess presumably because the plug does double-duty as a door depending on the floor plan.
The doors are very heavy, the pressure keeps them in place in only one direction. Without the bolts, only friction from the pressure would hold them up.
What seems odd is the springs that assist opening an emergency exit are left in place. Might not have made a difference.
It's up to chance that the door plug could bounce up, and thus ready to open when the pressure builds.
I would completely believe it if they claimed that they didn't manufacture up to specs, didn't install it correctly, cheaped out on the materials.. but painting over the plugs? Yeah....
That said, I worked in commercial aircraft engine component repair for years and everything I read in this is 100% plausible to me.
One time we shipped a part back to the customer before it was even done being repaired. It had labels and stickers marking stuff that needed to be done still on it. When the customer got it they emailed us some photos of the markings and said "It doesn't look done to us...". We had to tell them to send it back so we could finish it. Whoops!
I agree that the situation you are describing is very plausible. But correct me if I'm wrong but he's saying that Boeing knew (as in, their systems were aware) about it, even after the botched repair that there was no bolt. In this case, it would be closer to the customer knowing the repair wasn't done and still going forward with not sending it back. No checks are done even after malicious actions from spirit:
>the reason the door blew off is stated in black and white in Boeings own records. It is also very, very stupid and speaks volumes about the quality culture at certain portions of the business
>This entire sequence is documented in the SAT, and the nonconformance records in CMES address the damaged rivets and pressure seal, but at no point is the verification job reopened, or is any record of removed retention bolts created, despite it this being a physical impossibility. Finally with Spirit completing their work to Boeing QAs satisfaction, the two rivet-related records in CMES are stamped complete, and the SAT closed on 19 September 2023. No record or comment regarding the retention bolts is made.
To me that's just hard to believe. Errors happen, but this involves fraud from spirit and also just no process at all from Boeing. I get that the system that deals with this for the 737 is apparently bad, but this just very very basic process management (aka step y needs to be done so that step x can be marked as started or confirmed). In this case, Spirit earlier lied about repairing it, then still didn't repair it... for reasons (hard to procure parts for a manufacturer is an... odd reason to just not fix a critical part especially since it would mean that they actively decided to not install the missing parts). And Boeing caught it the first time but then stopped caring the second? Idk, possible, but I'll wait for sure for more info before drawing conclusions
the quote:
> there are 4 bolts that prevent the mid-exit door plug from sliding up off of the door stop fittings that take the actual pressurization loads in flight
I mean sure maybe but at best I'd guess the comment is based on the truth but with heavy hyperbole. And no matter what is said about Boeing, they still have in house inspectors and Qa. Even the laziest QA with no process management other than a spreadsheet would've caught this or raised a red flag. Would've also been believable if QA was overridden by management or something, but nope, nothing was raised according to the comment
quote from annother comment of that thread: https://leehamnews.com/2024/01/15/unplanned-removal-installa...
> Context: CMES – Common Manufacturing Execution System SAT – Situation Action Tracker
Spirit employees cannot get write access to CMES, by process. Going back to P poor quality of fuselage deliveries in 2018 Spirit teams have been onsite in Renton & Moses Lake.
It was common that Spirit could be doing out of sequence work all the way after factory rollout.
Frequently Boeing Senior Managers demanded CMES access for Spirit teams, but it can’t be allowed. Access to SAT is fine because it is not a production system.
When Wichita was part of Boeing system access was not an issue. The only way to integrate Spirit SAT entries & info into CMES is manually, and that is tedious and error prone. Information escapes are unavoidable when 2 companies are working in multiple systems of “record”.
Like what is this site even?
- too low pressure, meaning that the door might have been leaking before it blew out.
- too high pressure, meaning that the door had extra force on it.
But I can see how we could read to different statements from the parent.
Given the awful (criminal?) behavior of the repair team, it seems reasonable to assume the bolts were initially present and they just forgot to put them back - rather than that they were missing from the start.
> has in the past 365 calendar days recorded 392 nonconforming findings on 737 mid fuselage door installations
which prompted my comment.
then it says that the door in question was re-worked by Spirit employees. It implies that the bolts were removed and not re-fitted, but I don't see evidence that they were ever fitted. Perhaps they were, but then removed by people working for a company that day to day doesn't fit bolts, or perhaps they were never there and the people working for the non-bolt-fitting company didn't see the problem with that.
You have your screwed container of coffee you have a cup and a kettle of hot water.
Someone later finds the coffee container open and spilled by the resident cat.
There's no record of the container opened but there's requests for coffee and completed work orders for coffee have been billed which you can't do without opening the coffee container
Still sounds like a clear case of an unbelievable amount of bad quality from Spirit, and Boeing not pressing the issue until something finally slips through the cracks
[0] (not that they would for what is claimed to be literally just painting over the plugs, without installing anything. that's just dumb, it's not something you can just get away with, it would've been visible from the very first flights and would he basically a world's first)
How are they in any sense whatsoever still working with a company or process that would 'paint over the plugs'? That was the warning sign.
I'm sure the answer is money somehow but is that even accurate? Surely this is more costly? Different budget maybe?
Because there is no alternative supplier that could supply the same components in a shorter-than-years timeframe. And they don’t want to halt all production as it would bankrupt the company.
To the HN crowd, this is like AWS becoming broken and unreliable, but your entire build and architecture has AWS baked in. Moving to Azure or Google or whatever would take years of engineering and data migration. So you paper over the holes as best you can to keep the lights on.
Raw meat can happen, you catch it before you start eating it. In this case, it's more like you got a pack of used needles instead (pretty much equivalent to a non installed door in an airplane) because the chef didn't want to wait 5mins for the meat to cook, you basically just acknowledge the needles and start eating. That what is hard for me to believe. The original 737max controversy made sense, shortcuts were taken, and it made sense why that sort of disfunction would slowly creep into the design process. It also makes sense that some believed that the redesign would still work since hey, pilots just have to handle the errors if they happen! But in this case? The motivations don't make sense, especially since it apparently wasn't just a mishap or a failure, but intentional fraud.
Even if there were alternatives, it might irk them to acknowledge that outsourcing most (all?) of their manufacturing didn't end well.
As for buying them back, see [1].
Doing so would reduce their return on net assets.....
[1] https://www.aerotime.aero/articles/boeing-rules-out-buying-t...
As I read it, it's kind of the opposite. The records show a repair that required removal of the bolts, but there is no record of replacement of the bolts. And there is a record of discussion of if the repair required a formal inspection, which (I think) would have involved recording the status of the bolts.
This is taken as clear evidence that the bolts were not there, but IMHO, if the bolts were missing, that's where they went, but it might not be enough to show they were missing. Also, there's some clear process problems.
I'd sure like to know about the inspections on the other plug doors.
I don't fly anymore but I guess next time I'm going to have to build my own aircraft.