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Boeing 7*7: the saga continues…


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1 hour ago, JoeSchmuckatelli said:

Flew one of those home a couple of days ago... the stew kept looking at the door and commenting 'that looks weird'.

Thankfully, nothing exciting happened.

Also - re the pic above: row 26 does not look like an exit row.  

(or rather, not a planned exit row)

Was it an Alaska Airlines flight?

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1 hour ago, JoeSchmuckatelli said:

Also - re the pic above: row 26 does not look like an exit row.  

Apparently depends on seating config. Some configs don't have the exit and plug the door with an inoperable door with a window, and the inside plastic/whatever covers it so you can't tell it was a door.

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For context: In my former life as a hostage of certain Pakleds, we had two cases of engines puking out their guts over the arctic. The fuselage and empennage were peppered with shrapnel, puncturing holes and necessitating single engine diversions to remote airports. The incidents were arguably equally or even more serious than this Alaska Airlines incident (it also resulted in an emergency AD), but it didn't make the news. As a result, there weren't any so called "experts" bleating about the type being unsafe. The industry did the inspections of the affected engines and moved on. That's how the system works and it generally does so quite well.

Edited by PakledHostage
Fixed weird doubling up of post
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1 hour ago, PakledHostage said:

That's how the system works and it generally does so quite well.

I would say that anything with an airliner is public, almost certainly with video. It's news. It's local news here in ABQ when a flight diverts here for any reason—even and unruly passenger.

In this case it's also a type plagued with serious issues. Even after the whole MCAS issue, they started inspecting and found junk left in the various void spaces, right?

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I am not trying to suggest that this incident isn't news. I am also not trying to downplay the seriousness of the evident manufacturing/quality control defects. What I am trying to say is that the industry and its regulatory partners generally do an excellent job of ensuring high levels of safety. Lots of stuff happens that doesn't make the news. Some of that stuff that doesn't make the news even makes industry insiders go "holy crap, that was close!" (a certain runaway horizontal stab trim event springs to mind). But what's tiring in cases like yesterday's are the people with an axe to grind (or who are seeking their  own 15 minutes of fame) who come out of the woodwork to make hay out of the incident. That does nobody any good.

Edit: I should add that the runaway horizontal stab trim incident I am thinking of happened on an  Airbus, not a 737 Max. The Max didn't exist yet at the time.

Edited by PakledHostage
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I live in Portland so this was all over the local news.

Here’s a piece @PakledHostage might agree with (at least partially).

https://www.koin.com/news/oregon/seattle-aviation-lawyer-pilot-calls-alaska-plane-incident-preventable/

The Seattle-based aviation attorney says he thinks it is an isolated incident, not a major defect with the MAX. I take this to mean it could have happened with any aircraft.

Alaska had already cleared 18 of 65 MAXs to return to service by the way.

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49 minutes ago, SunlitZelkova said:

Alaska had already cleared 18 of 65 MAXs to return to service by the way.

I wonder how you'd possibly clear them without first understanding the failure mode of the door in question?

 

There are 12 stop pads on the fuselage (and 12 stop fittings on the door), and 4 bolts, 2 upper, 2 lower. The bolts were possibly all sucked out with the door, but if pieces remain, those would need to be studied to see if they failed before the door was torn away, or as a result. Or if the hinges or guide fittings failed. It seems incredibly unlikely that all this has been determined in a day.

Edited by tater
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20 minutes ago, tater said:

wonder how you'd possibly clear them without first understanding the failure mode of the door in question?

Well, it was a new plane. Do we know if they found anything yet? They should have some idea of  went wrong with the installation by now. So they pull the panels off the other aircraft and verify that everything is in place that should be there, and make sure there are no signs of fatigue, movement, or wear.

Then they give it a slap and call it good, like they apparently did at the factory without the verification that it was installed properly…

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28 minutes ago, StrandedonEarth said:

Well, it was a new plane. Do we know if they found anything yet? They should have some idea of  went wrong with the installation by now. So they pull the panels off the other aircraft and verify that everything is in place that should be there, and make sure there are no signs of fatigue, movement, or wear.

Then they give it a slap and call it good, like they apparently did at the factory without the verification that it was installed properly…

heh, dunno. Seriously, it first flew in Oct. It can't be fatigue unless maybe it was loose to start? (bolts not tightened) But they could not know that yet, right? So all they can do to check until then is open them up, and say, "Yep, this looks the way they should right out of the factory!" (just like the door that just fell off did a couple months ago did)

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13 minutes ago, tater said:

"Yep, this looks the way they should right out of the factory!"

Ah, but did it? Did anyone ever verify bolts were torqued and nothing was missing before closing the panel and signing off on it? We just don't know, but we do know they've been fighting with QC issues. Between the newest 737s and Starliner, Boeing appears to be going down like a Max with an MCAS malfunction and clueless pilots...

"Too big to fail" vs "the bigger they are, the harder they fall..."

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24 minutes ago, StrandedonEarth said:

Ah, but did it? Did anyone ever verify bolts were torqued and nothing was missing before closing the panel and signing off on it?

That's a distinct possibility. NTSB had the first brief a couple hours ago with no tech information at all. She said the first real day of work will be tomorrow. Clearing planes right now seems like a joke.

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My experience is from a long time ago and my aging brain may also have forgotten some details, but as I recall, the Boeing doors are all plug doors. (At least that's true on the bigger Boeings that were my purview.) The  mechanism brings the door in and then down onto the stops on the fuselage. Pressurization loads are resisted by the stops, not by the latches and, those pressurization loads push the doors closed more tightly.  The doors are rigged so that all the stops are loaded equally.

Boeing has built a lot of doors on a lot of airplanes over the decades. This isn't something new and novel. I am not going to speculate about what failed on this door, but I would be surprised if it turns out to be something out of left field. The AD doesn't specify what inspections should be done, but I expect that they'll remove the plug, do some NDT inspections on the stops and then double check the rigging and that the plug is properly retained when it is unpressurized. (Because, again, the ones I am familiar with are designed to seat more firmly as the aircraft is pressurized, and if they're properly positioned, they wont go anywhere once loaded). The mandate may also require repetitive inspections at some interval that can be done in the course of normal maintenance (e.g. A-check intervals) once the first round of "before further flight" inspections are completed.

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From https://news.alaskaair.com/alaska-airlines/operations/as-1282/

(I'm cutting out a bit of marketing and corporate speak, so check full text)

Quote

[...]Alaska made the decision to temporarily ground its 737-9 MAX fleet pending inspections which began early this morning. [...]

[...]Today, the FAA issued an emergency airworthiness directive (EAD), requiring all operators of the 737-9 MAX aircraft to conduct specific inspections before returning the aircraft to service.[...]

[...]Our voluntary temporary grounding of our 737-9 MAX fleet and ongoing work to comply with the FAA’s EAD [...]

[...]Eighteen of Alaska’s 737-9 MAX aircraft received in-depth inspections as part of heavy maintenance checks and continued in service today until we received the FAA’s EAD. These aircraft have now also been pulled from service until details about possible additional maintenance work are confirmed with the FAA. We are in touch with the FAA to determine what, if any, further work is required before these aircraft are returned to service.  [...]

Am I reading this correctly? Plug blows out, AA makes a voluntary decision to ground its entire 737 MAX fleet of 60+ planes, checks 18 of them, declares them A-okay and returns them to service. Then FAA issues EAD and they reground the fleet?

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39 minutes ago, Shpaget said:

Am I reading this correctly? Plug blows out, AA makes a voluntary decision to ground its entire 737 MAX fleet of 60+ planes, checks 18 of them, declares them A-okay and returns them to service. Then FAA issues EAD and they reground the fleet?

I could see that happening. They try to do the right thing on their own and then the AD comes out that calls for something different than what they did so they need to back and do it again.

In my tenure as a hostage of Pakleds, the mechanics once found serious cracks in a landing gear lug, so we took it upon ourselves to ground the fleet and perform an inspection on all our aircraft of the type before further flight. We then told the regulator and manufacturer what we'd found and what we did about it. Fortunately, they agreed that what we did was sufficient and the resulting AD just said to do what we did, but if they'd have asked for more, we'd have had to ground the fleet a second time.

Edit: Thinking about it some more, it may also be that Alaska Airlines found more problems on more airplanes when they did their inspections and that's what prompted the FAA to issue the emergency AD. In the landing gear crack episode I mentioned above, the mechanics found two incidences of cracking, so we grounded the fleet (it was night time so most of them were on the ground anyway) and called for an inspection. We then told the regulator and the manufacturer in the morning and they took it from there. If Alaska Airlines found more problems on more aircraft when they did their first round of inspections, they would also have notified Boeing and the FAA, and an emergency AD would be the expected outcome.

Edited by PakledHostage
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6 hours ago, StrandedonEarth said:

Do we know if they found anything yet?

https://www.koin.com/news/oregon/ntsb-press-briefing-alaska-air-1282-boeing-737-max-9-pdx-01062024/
 

The area the door is in is near the hospital I was born (for real).

Could they have tracked it falling on radar? I think there is an ASRS-4 or whatever the main CONUS radar is not too far from Portland.

EDIT- And in case you check the Pacific time zone and wonder why I posted this at 3:00 AM, well… university’s winter break isn’t over yet and I’m something of a night owl.

Edited by SunlitZelkova
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15 hours ago, tater said:

Odd that they would not plug these doors from the inside with an internal flange that is larger than the opening. Then it could not possibly do this.

They do. Sort of. Like any door, there has to be a way for it to open.

For the main cabin doors, that means pulling it in a little, and then translating it a little until it fits through its own opening.

With this door it works a little differently, but if it is in place then it is a plug that can't fit through its own frame. Apparently this one was not properly held in place. But that's just an assumption. There will be a final report.

Edited by mikegarrison
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3 hours ago, mikegarrison said:

They do. Sort of. Like any door, there has to be a way for it to open.

I looked at the images and there are 12 overlaps like that (small), and apparently the door is lifted slightly so the flange "pads" are no longer overlapping, and it can then open. What I meant was for a "door" that is never to open, why not make it larger around the entire perimeter, then simply install it from the inside. It can only then be "opened" by removing the plastic panel, unbolting, and pulling the door into the cabin.

It seems like it must be a 1-off, though, since I guess this works like every other door (and a zillion are flying with no problem)? Perhaps 1 or more bolts was not tightened appropriately, and this resulted in some vibration that wore the others down, or loosened them?

I know squat about it, just seems odd to clear other aircraft without understanding the failure mode. No idea if this is a thing, but what if there was a bad batch of bolts (or even part of a batch—the last 10 bolts in some run were not at spec)? Somehow they don't meet spec, and they snap. Those specific bolts could be on other doors, and look fine, properly tightened, but if you x-rayed them, they'd have some sort of visible flaw.

Spitballing, I have no idea. Hopefully they find as many parts as possible.

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14 minutes ago, tater said:

I know squat about it, just seems odd to clear other aircraft without understanding the failure mode. No idea if this is a thing, but what if there was a bad batch of bolts (or even part of a batch—the last 10 bolts in some run were not at spec)? Somehow they don't meet spec, and they snap. Those specific bolts could be on other doors, and look fine, properly tightened, but if you x-rayed them, they'd have some sort of visible flaw.

Over the years, I have stayed out of these discussions and left it to @mikegarrison to comment because he seems to be able to say in 1 or 2 sentences what I try to say in 5-10 paragraphs, but this is what I was beating around the bush about above. The inspections required will depend on what they think the failure mode might be. They might cast a wide netand look at lots of things while they have it open, or they may have a good idea of the failure mode and focus on just that.

They might also call for a progressive inspection where if you find A, you have to do B, but if you don't find A you can close it back up. And if it is something that might recurr, crop up over time or get worse over time, then they'll call for a repeat inspection too. 

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27 minutes ago, darthgently said:

From a layman's view, looks like the entire door frame pulled free?

No. Watch the vid I posted above about the mid-cabin exit doors. See the little tabs in that image? The door had tabs that sat inside of those. Meaning more inside the aircraft. To open the door has to slide UP, and clear those tabs (12 of them). There are also 4 bolts (cause these doors are not supposed to actually open). 2 at the top, and 2 on the hinges at the bottom. maybe if the bolts broke, the thing could slide down a cm or 2 and, then gets blown out (higher pressure in the cabin).

The specifics might be wrong, I only know from the video and pics.

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41 minutes ago, tater said:

No. Watch the vid I posted above about the mid-cabin exit doors. See the little tabs in that image? The door had tabs that sat inside of those. Meaning more inside the aircraft. To open the door has to slide UP, and clear those tabs (12 of them). There are also 4 bolts (cause these doors are not supposed to actually open). 2 at the top, and 2 on the hinges at the bottom. maybe if the bolts broke, the thing could slide down a cm or 2 and, then gets blown out (higher pressure in the cabin).

The specifics might be wrong, I only know from the video and pics.

Yeah, I was looking at those tabs after I posted and figured I'd get corrected as they seemed part of the "door frame"

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23 hours ago, JoeSchmuckatelli said:

the stew kept looking at the door and commenting 'that looks weird'.

No they didn't. Stop making stuff up.

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