Oh Alaska/Boeing

Roger Roger said:
I’m extremely new to the game but the only way I see myself remembering to do that after having the cockpit door blown open in an honest to god rapid decompression is someone from the ground (FODO? CP? IDK) who isn’t on the adrenaline high of their life walking me through whichever checklist that would be, once the parking brake is set and while waiting for EMS and the inevitable drug test.
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It’s buried in the FOM. Supposed to pull CVR, FDR CBs, write up in the logbook that they’ve been pulled, and notify FODO of the logbook entry.
 
arkflyr said:
Here is a good technical video going over the differences between the actual door vs the plug and how it is secured. And refreshingly free from inane speculation and opinion.


View: https://youtu.be/maLBGFYl9_o?si=AaNzvwXye8Wlb5QH
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Roger Roger said:
Possible. I don’t know why people are surprised that it isn’t riveted though, the whole point is that you can convert it to a real door and that’s hard to do if you have to drill a bunch of sheet metal to make it happen. I am a little surprised that it isn’t a plug type where pressure seals it tighter though, I kinda thought that was a no-no on an airliner.
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Roger Roger said:
So something from that video, the statements above about it not being a plug type are incorrect. It IS taller than the hole and has to be moved down and in before it will open. The plot thickens.
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Thanks for these - unfortunately I can’t go back and edit my post, but that’s a fantastic video. The original image from NTSB Twitter didn’t make clear the guide rollers with the retention bolts:

B9A657FC-4CF6-4699-9983-C0406E126933.jpeg

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That’s more robust than I originally thought, which was the door swinging shut from the outside and being held closed with tension bolts. Agree about drilling rivets being a crappy temporary solution - but my rivet comment was more that bolts in tension are a lousy way to react pressure loads and lap shear is the preferred method due to hoop stress on a pressure vessel. A traditional Plug door is heavier than lap shear in a skin but the overlapping lip mechanically locks the door in place.

Sounds like this design is good enough (as evidenced by the -900 record) but not idiot proof since you need to swing the door closed from the outside, then translate it up (or down?) to seat the lip while engaging the rollers in the guides, then install the 2 bolts that retain the upper rollers and the other 2 bolts that lock the springs on the bottom hinges. I’m sure this decision (like all aerospace decisions) was a trade on weight and cost, but I’d personally feel better knowing that the thing buried behind the wall that’s non inspectable had a slightly more robust attachment method (ie a lip on more than one edge).

It will be interesting to read the NTSB report and learn what broke (or was missing?) now that they recovered the door. If that particular airplane was having past pressurization issues I won’t be shocked if the lip wasn’t seated all the way or maybe rollers were on the wrong sides of the bolts meant to retain them?
 
inigo88 said:
Thanks for these - unfortunately I can’t go back and edit my post, but that’s a fantastic video. The original image from NTSB Twitter didn’t make clear the guide rollers with the retention bolts:
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Yeah, I guess I can take the engineering fremndschämen back, and merely replace it with a certain amount of "whelp, so."
 
I don’t think Boeing has QA anymore. Loose bolts on plug doors found on at least 5 aircraft so far.

theaircurrent.com

United finds loose bolts on plug doors during 737 Max 9 inspections

United Airlines has found loose bolts and other parts on 737 Max 9 plug doors as it inspects its fleet of Boeing jets following the Friday rapid depressurization aboard an Alaska Airlines jet of the same make, according to three people familiar with the findings.
theaircurrent.com theaircurrent.com
 
Cherokee_Cruiser said:
They’ve wanted it for years.


I’m no ALPA blow hard. We need to suck it up and have 25 hr CVRs. The caveat being a guarantee, contractually, that mgt won’t use any of it for their snooping purposes. Whatever protections we currently have from mgt for a 2 hr CVR, have them agree to it for 25 hrs.

If I had to bet, mgt across the industry is ready. It’s ALPA being ALPA chest thumpers.

The NTSB mentioned several cases, including literally all recent runway incursions, in which they don’t have a CVR to reference.
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If they want to go to Canadian rules about the CVR, where it is considered highly privileged information, and only 3 people hear the recording and no transcript is ever published (only a summary), maybe there's room to talk.

Otherwise, um, no.
 
NovemberEcho said:
I don’t think Boeing has QA anymore. Loose bolts on plug doors found on at least 5 aircraft so far.

theaircurrent.com

United finds loose bolts on plug doors during 737 Max 9 inspections

United Airlines has found loose bolts and other parts on 737 Max 9 plug doors as it inspects its fleet of Boeing jets following the Friday rapid depressurization aboard an Alaska Airlines jet of the same make, according to three people familiar with the findings.
theaircurrent.com theaircurrent.com
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QA?

I’ve been told that the ONLY purpose of a corporation is to produce shareholder value!1!1!1!1
 
Richman said:
If they want to go to Canadian rules about the CVR, where it is considered highly privileged information, and only 3 people hear the recording and no transcript is ever published (only a summary), maybe there's room to talk.

Otherwise, um, no.
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this is about 50% of my mind on the topic.
 
Apophis said:
QA?

I’ve been told that the ONLY purpose of a corporation is to produce shareholder value!1!1!1!1
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As head scratching as this whole thing is, how incredibly lucky are we, really? I mean it looks like at least dozens of aircraft were flying around with this issue, and we learn about it (so we can fix it) because one blows off below the flight levels and with nobody in the two affected seats? Lot to feel fortunate about here.
 
Inverted said:
See, we should be aircraft manufacturer CEOs. We get it...
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Yeah…some of the things that Uncle Clyde did still make me twitch. Can’t say enough good things about the engineers who designed airplanes to be built by rednecks and flown by flight schools or owners but man. At least I’ll say that Boeing seems to make the quality there seem outstanding.
 
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