Originally Posted by
thnarg
Just a thank you for all the explanations and theories. I haven’t had time to read everything so a couple of stupid questions from a retired driver:
Is the door plug just a stripped down normal exit door without a slide bustle?
Were the previously logged cabin pressure controller faults due to leakage induced bleed flow or something else?
And, if I may, supplemental irrelevant questions just for interest:
Does a 737 Max need a running (not just serviceable) APU for 180ETOPS?
Are Max main doors still dis/armed by kneeling and praying to the god of the girt bars, or have they been updated?
Note the bolt hole in the roller guide
I’ll first answer question #2: the previously logged cabin pressure controller faults have been mentioned several times in the thread, and they were reported to be not linked to cabin air leakage.
Still, I think I’ve read that hissing noises had been reported nevertheless. Investigators will still have an open ear for this detail!
Now I come to your main question. See image above.
The door plug is an optional different and lighter ‘stand-in’ that has been designed to be compatible with the door frame around the opening for the additional emergency door devised for NG 900 / MAX 9 fuselages with high density seating. It has one normal passenger window (instead of the two windows that would probably fit in the space of the emergency door AND the surrounding door frame). Otherwise it’s a permanently covered structural hole-in-the-wall. Even from the outside it’s not too noticeable.
It lacks the inward-opening shoe-sized vent door in the uppermost part of the emergency door. And it lacks the handle for opening from the inside, and the slide pack in its bustle. Have a look at the post behind this permalink:
Alaska Airlines 737-900 MAX loses a door in-flight out of PDX .
It has no passenger window, but instead the typical small window for a standing person to oversee the outside conditions before deciding to actually open the door.
However, in looking for the linked image, I now dis-covered something that I didn’t notice before. The image reveals that the standard emergency door shows a small dark hole in the door-mounted guide for the fuselage-mounted roller. This looks like the hole where (in case of a door plug) the bolts that everybody is searching for should be to restrain the door (EDIT: door
plug) from moving upwards.
I’ll have to leave the slightly off-topic two other questions open.