Boeing 737 Max again, it would be nice if the windows [door plugs] stayed in! - Page 1
Forum section: electronics / general

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2024, 01:19:15 pm
content: 'My God, it's full of stars'Alaska Airlines has grounded its fleet of 737 Max 9s after a cabin window and part of the fuselage blew out at a mere 16000ft! I shudder to think what it would have been like at 30000 ft, as it was, a kid lost the shirt he was wearing. Luckily there was nobody in the window seat, which had its cushion stripped off...https://www.bbc.co.uk/news/world-us-canada-67899564Not a S/W problem this time, unless maybe you include CAD, but a hell of a QA failure!Edit: I missed the one on 29th December where a rudder control system bolt was found with no nut on it - Airlines were asked to inspect to see if their bolts were loose "Out of an abundance of caution..." Hmm.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 06, 2024, 01:39:29 pm
content: When they developed the original 737 airframe into the MAX airframe, I don't think windows were changed were they?In other words, this problem potentially affects all 737s, not just the MAX. That's assuming it's indeed a design flaw, as opposed to lax maintenance.

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2024, 01:50:20 pm
content: Looking at it further, it appears that that window was part of a 'factory deactivated' emergency exit which has a row of seats in front of it on the Alaska Airlines stock. It looks as if it would have facilitated in-flight exit without touching the sides!Altitude ceiling is specified at 41000ft, so it was really low when it happened. I though all plane exits were inward opening before swinging?

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 06, 2024, 02:28:20 pm
content: Quote from: Andy Chee on January 06, 2024, 01:39:29 pmAlaska Airlines was infamous for bad maintenance, the crash of Flight 261 inspired the movie Flight.

author: themadhippy
author_rank: Super Contributor
timestamp: January 06, 2024, 02:41:21 pm
content: Quoteeven though it sounds like a bad windows installation

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2024, 02:43:45 pm
content: Quote from: NiHaoMike on January 06, 2024, 02:28:20 pmI wonder what maintenance / inspection is specified for something like that. Presumably it is made to look like a normal window behind what looks like widely overlapping wall trim (I know all interior trims and seats are removed for major inspections).I always though plane doors are impossible to open when the cabin pressurized though. I always used to try an get an emergency exit seat for the legroom, before they started going down the queue offering them at extra cost. Maybe there's something to be said for having your kneecaps squashed tight against the seat in front.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 06, 2024, 03:17:31 pm
content: Quote from: Gyro on January 06, 2024, 02:43:45 pm

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 06, 2024, 09:29:40 pm
content: That doesn't bode well.

author: Gyro
author_rank: Super Contributor
timestamp: January 06, 2024, 09:39:24 pm
content: Quote from: Andy Chee on January 06, 2024, 03:17:31 pmHmm, that's what I thought. That probably rules out Boeng using the wrong nails when they nailed it shut. Presumably a tapered door can't shrink, so the tapered frame suddenly getting bigger?I wonder if they saved on the door and frame and 'factorydisableddeactivated' means 'bolted something else in instead'.I see that US regulators have now ordered the grounding of 171 further Max 9s for inspection.

author: Ranayna
author_rank: Super Contributor
timestamp: January 06, 2024, 09:41:02 pm
content: Quote from: Gyro on January 06, 2024, 02:43:45 pmIn this case i would not think that maintenance was the issue here.The plane was just 10 weeks old.I have no idea how much maintenance it would have required in this time, but i would think that maintenance on such a "factory deactivated emergency door" would be very rare, if ever required outside of a major overhaul.Also not just this "door" ripped out, the whole panel containing the door was ripped, rendering all security features of the door itself totallty moot.

author: tooki
author_rank: Super Contributor
timestamp: January 06, 2024, 10:55:22 pm
content: Quote from: Andy Chee on January 06, 2024, 01:39:29 pmThe aircraft in question is only two months old, so I think we can confidently rule out maintenance.So my hunch is an assembly mistake, not a design flaw or bad maintenance.

author: tooki
author_rank: Super Contributor
timestamp: January 06, 2024, 10:57:23 pm
content: Quote from: Andy Chee on January 06, 2024, 03:17:31 pmIt was an emergency exit, not a regular door. Not sure if those use the same mechanisms.But as Ranayna said, the door/window latching mechanism design is irrelevant if the whole wall tears off…

author: abeyer
author_rank: Frequent Contributor
timestamp: January 06, 2024, 11:17:15 pm
content: Quote from: tooki on January 06, 2024, 10:57:23 pmExcept it wasn't a "whole wall" from what it looks like: the "panel" that came off was only the interior trim panel that covered the door, which was presumably blown out by the pressure when the door failed, but pictures clearly show the door frame/structure still seemingly intact on the plane and no other obvious structural parts missing.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: January 07, 2024, 12:15:52 am
content: https://www.flightradar24.com/blog/alaska-airlines-737-9-max-exit-door-separates-in-flight/

author: MarkS
author_rank: Unknown
timestamp: January 07, 2024, 12:31:27 am
content: It's called a plug door. It's an opening designed as an optional emergency exit and was plugged in this case. The plug came out. The question is, why?

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 07, 2024, 01:03:28 am
content: Well, maybe Boeing should have pulled the plug.

author: tom66
author_rank: Super Contributor
timestamp: January 07, 2024, 01:28:39 am
content: Flashback to this event, also on a 737 (though an earlier 737-700, delivered in 2000).https://en.wikipedia.org/wiki/Southwest_Airlines_Flight_1380Uncontained engine failure caused cabin damage and led to a woman unfortunately being partially sucked out of the aircraft. Whilst passengers managed to keep her inside the aircraft, she succumbed to her injuries (blunt force trauma according to the health department).Obviously, there's quite a difference between an uncontained engine failure on an ~18 year old engine, and a door failing after just a few months in service. NTSB will surely want to find that door.

author: tooki
author_rank: Super Contributor
timestamp: January 07, 2024, 01:50:40 am
content: Quote from: abeyer on January 06, 2024, 11:17:15 pmWell if it’s a plug-style door, then either:- a section of wall would have had to go with it (=door stayed intact, wall failed)- the wall is intact but the door itself failed- it’s not a plug-style door at all, despite being called a “plug”

author: schmitt trigger
author_rank: Super Contributor
timestamp: January 07, 2024, 01:55:38 am
content: If I had been the quality inspector at the Boeing factory where this plane was assembled, I would be scared shitless right now.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 07, 2024, 02:59:47 am
content: Maybe the problem is that the inspectors DON'T fear escapes.But really this is just one more but of unfounded speculation. I could come up with a list of guesses longer than your arm. Probably ought to wait for the investigation.

author: floobydust
author_rank: Super Contributor
timestamp: January 07, 2024, 03:09:24 am
content: Dennis Muilenburg, former President, chairman and CEO of Boeing did run the company literally into the ground.Firing all the senior staff, whether engineers or production staff and then outsourcing - does have a consequence that MBA's and Wall Street can't fathom.His$80Mgolden parachute, when he should be in jail.Thank God his investment firm New Vistafailedand he cannot do more damage to other companies as a SPAC (special purpose acquisition company, "blank cheque"). Canadian Flair Airlines he wanted to acquire and presumably also run into the ground.I have seen, if you have constant a churn of staff, new hires then there are a lot of mistakes made. Almost impossible to repair a trashed corporate culture after a bad CEO leaves.pichereit seems the entire door frame blew outand there is wiring, cables at the bottom edge.

author: bdunham7
author_rank: Super Contributor
timestamp: January 07, 2024, 04:18:24 am
content: Quote from: floobydust on January 07, 2024, 03:09:24 amI'm not in the Dennis Muilenburg fan club, but it was Jack Welch protege James McNerny who really destroyed Boeing from the inside out. These types of chickens take a long time to come home to roost, and a lot of damage was also done by Harry Stonecipher after the McDonnell Douglas takeover. It took a sustained 20 year effort to get Boeing to where it is today.And yes, all of them should have been working as WalMart greeters after they served their prison terms instead of walking away with a metric ton of cash.

author: bdunham7
author_rank: Super Contributor
timestamp: January 07, 2024, 04:56:54 am
content: Quote from: tooki on January 07, 2024, 01:50:40 amThese, like many airline doors, are not truly 'plugs' at all as you'd imagine them to be, given the folklore that they are impossible to open when pressurized. What actually happens is that to open, instead of swinging inward only like you'd imagine a 'plug', they merely have to slide upwards a bit to get clear of multiple retaining stops and then they can swing out, down or fall off as the case may be. In theory, pressurization will force the door against the retaining stops and prevent that upward sliding from happening. In reality, the plane isn't always pressurized.In this case, part of the issue is that it wasn't a door at all, just a dummy 'plug' that they put in the doorframe. At some point it came free and slid up and off its stops a bit, then later when pressurized.....POP! A regular door being loose would have been noticed and set off alarms, but the dummy doesn't have sensors or alarms AFAIK. There's a decent video going over these details. Somebody screwed up, I'm guessing we'll know who soon. It wasn't me!https://youtu.be/nw4eQGAmXQ0

author: floobydust
author_rank: Super Contributor
timestamp: January 07, 2024, 05:24:28 am
content: Quote from: bdunham7 on January 07, 2024, 04:18:24 amThe pump'n'dump stock chart I thought mainly happened over Muilenburg's rule. Is it a good time to buy some Boeing stock lol. What's a door plug and a few bolts.Although I can't imagine "forgetting to put those bolts in" happens without absent QA checks and the staff to do them.I remember reading that corporate cultures never recover once crooks take over. It leaves people CYA and back-stabbing as the focus, no trust anymore. A CEO's aggression and putting shareholders first does too much damage.

author: pickle9000
author_rank: Super Contributor
timestamp: January 07, 2024, 05:36:15 am
content: Best description of the event.