Boeing 737 Max 9: United Airlines finds loose bolts during inspections
Boeing 737 Max 9: United Airlines finds loose bolts during inspections
The airline finds installation issues, including bolts in need of "tightening", during checks of Boeing planes.
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After looking at that diagram I have to ask - why in the everliving fuck would a pressure bearing panel like that be hung by bolts and not inserted into the cabin and held in place by the ribs of the fuselage? I mean seriously?
I don’t get why they don’t just make it a bit bigger on the inside so that when pressurized, the pressure itself seals it. Seems like a fail safe solution instead of this shadiness.
But mah profits!
737 Max is still a developing example of what happens when you leave corporate to self-regulate themselves.
It's a well documented that when Boeing merged with McDonald Douglas, they turned from an engineering led company to an executive led one & have been shit since
I think it's to save space. See: DC-10 Cargo Door fiasco
It does. It is still a plug-type door. It pushes against 12 stop pads. This design has been used for many years, including on the 737-900 that predated the Max9. You can see the exit plug in this photo form 2007, before the Max was even a thing. Also, cargo doors have worked the same way for many more years than that.
They do it so that the door does not have to swing the whole way inside to fit out.
It is, kind of. The plug is secured by 6 stops (or tabs) along each side. The positive pressure differential pushes the plug outwards into those stops.
To remove the plug you uninstall 4 bolts which allow the plug to go up and over the stops, after which it can hinge outwards on a hinge found at the bottom of the plug.
Just seems like a better design would be if no bolts existed (like from them loosening over time and falling off), it would still be sealed perfectly fine. The obvious failure point is the bolts and seems they could do better.
It’s a door plug, which means it’s meant to be replaced with an actual door if required, so a lot of the hardware for an actual door are in place. Doors are designed to slide in, then raise up so the stop pins engage the stop fittings from the inside, so the door is in effect bigger than the hole it’s in. this video provides a detailed explanation of how it works.
The big issue here is that the airplane is only 2 months old, it was delivered from Boeing in late October. Which means it’s either a design flaw or a process flaw in the original manufacturing. This smacks of corporate cost cutting again. Boeing are totally on the hook for this and it’s only lucky there were no lives lost. You watch, they’ll blame it on the airline initially but the fault will come back round to them again.
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this video provides a detailed explanation of how it works.
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That's how the normal doors work because they aren't permanently secured in place. The reason is weight as it pretty much always is in aviation design.