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

theaircurrent.com

241–250 of 773 posts

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

#241

How is Airbus doing meanwhile? I didn't hear about any production quality issues in their aircraft.

> The A320neo family has had four ground fatalities and one hull loss accident as of November 2022. https://en.wikipedia.org/wiki/Airbus_A320neo_family A320neo is the direct competitor to the MAX. So yeah, they're doing pretty well.

And that hull loss wasn't on account of a faulty design, assembly or process issues.

Crew and passengers were unharmed after a collision with a firetruck crossing the runway while the aircraft was doing its take-off roll.

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

#242
post #5

Earlier quoted context omitted.

Maybe the plugs aren't flanged enough? If the walls are mostly flat you could see the bolts being load-bearing.

My money is on the window. It was compromised and then the plug/bolts/flanges structure was ripped out of the body.

You'd lose your money. The plug is inserted from the outside and retained with fasteners against cabin pressure.

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

#243

Check out this video showing how the plug is supposed to be installed: https://youtu.be/maLBGFYl9_o?t=540 Some of the bolts that would be loosened when the plug is opened during maintenance have a pin to prevent them from turning. That pin is present in this photo: https://x.com/byerussell/status/1744460136855294106?s=46&t=s... However, the same photo shows other critical bolts that hold the whole hinge on the door a…

More rampant speculation! Some quotes from this article: https://www.reuters.com/business/aerospace-defense/spirit-ae... > As part of the production process, Spirit builds fuselages for 737s and sends them by train with the special door assembly “semi-rigged,” one of the people said. > “They are fitted but not completed," the person said. > At its Renton, Washington, plant, Boeing typically removes the pop-out, or no…

There’s no way that this is what happened. They’re not building IKEA furniture, everything is tightly check-listed.

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

#244

I have a dumb question: why "plug" the doors at all? Why not burn a row of seats and have an extra safety door? Was this at request of the airlines to "meet" minimum safety standards or was there a reason why it's "better" to have less exit doors?

If the regulators don't require the extra exit door, then the airlines would rather put in an extra row for more profits. The extra safety door is only needed depending on seating configuration.

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

#245

Earlier quoted context omitted.

I think it would require a fatal air crash of an American flight with a major celebrity on board.

. . . and the US airline industry has still not had a fatal crash in just under 25 years.

What is considered a US airline, and I'm assuming the minimal fatality count is 1 right?

https://en.wikipedia.org/wiki/PenAir_Flight_3296

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

#246

Check out this video showing how the plug is supposed to be installed: https://youtu.be/maLBGFYl9_o?t=540 Some of the bolts that would be loosened when the plug is opened during maintenance have a pin to prevent them from turning. That pin is present in this photo: https://x.com/byerussell/status/1744460136855294106?s=46&t=s... However, the same photo shows other critical bolts that hold the whole hinge on the door a…

"Loose bolts" is not a ton of detail. It could have nothing to do with any of the bolts discussed in that video.

I'm having a hard time imagining how this failure could occur from just those bolts "needing tightening". They are lock bolts with pins and appear to take shear forces and provide no clamping functionality. Even if the bolts were "loose", or not torqued to spec, how would they come all the way undone? Then the bolts, under shear, work their way out completely? And isn't the lift spring forcing the top pins into the upper part of the track? On top of that the curve of the track appears to be such that outward force on the door would actually cause the pins to go into the upper part of the track.

IDK, seems like there is something else going on. Different bolts maybe.

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

#247
Literally just flew on a United Airlines 737 MAX 9 one week ago. It seems like the craft I flew on has probably been grounded in the week since. I noticed that we were flying on a MAX before boarding and nearly asked to switch flights, but consoled myself that I was being irrational and that the planes were almost certainly fine now. Guess my confidence was misplaced.

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

#248

Earlier quoted context omitted.

> The A320neo family has had four ground fatalities and one hull loss accident as of November 2022. https://en.wikipedia.org/wiki/Airbus_A320neo_family A320neo is the direct competitor to the MAX. So yeah, they're doing pretty well.

And that hull loss wasn't on account of a faulty design, assembly or process issues. Crew and passengers were unharmed after a collision with a firetruck crossing the runway while the aircraft was doing its take-off roll.

Exactly, as I understand all those occurrencies were due to people on the runway for one reason or another.

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

#250

I have a dumb question: why "plug" the doors at all? Why not burn a row of seats and have an extra safety door? Was this at request of the airlines to "meet" minimum safety standards or was there a reason why it's "better" to have less exit doors?

Less cost and weight, and more rows. Only advantages there.
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