Quote:
Originally Posted by flybigjet
No, no, no.
The light had NOTHING to do with the door.
Literally..... NOTHING.
The door is a plug that's installed at the factory in case the aircraft operator later wants to convert to high-density seating. If they do, the additional seats are added, the plug is popped out and another emergency exit is added.
You literally (there's that word again) can not access any part of the plug from inside the airplane without depanelling it. The plug is supposed to be permanently installed, so there's nothing to check— at least not until a heavy maintenance visit when they pull the interior of the airplane apart, and these jets were too new for that to have happened yet.
The pressurization system does give warning if a door is open or not indicating closed— but that's only for the two doors in front, the two or four (depending on model) over the wings, and the two in the rear (there are some other doors like the avionics service door, but we'll ignore them since they're not in the passenger cabin).
But none of that matters here. The light that the NTSB is talking about is the the auto-pressurization controller light. It's COMPLETELY unrelated to the door lights mentioned above. The auto-press light comes on when the pressurization computer decides that the system isn't working properly to pressurize the plane— so it shifts to a backup computerized system. The usual fix is to replace the pressurization control box, which is located over the First Officer's head— it's a simple job— four screws, a couple cannon plugs and you're done...... IF you have [...]
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If that plug was loose in the fligts leading up to the incident seems quite possible that the plane was losing pressurized air through it and triggering the alarm. As the plug went through pressurization cycles it vibrated and further loosened over time and then the event. This is a hypothesis based on the information that is public.
Subsequent inspections have found loose bolts securing the plug on other aircraft. To say the failed plug was 100% unrelated to the preceding pressurization alarms at this point probably not possible.