Originally Posted by
hec7or
Might it be both pressure controllers experienced an uncommanded change of cabin pressure and attempted to initiate an auto transfer which failed and caused the auto fail light to illuminate
I was thinking the same kind of thing. If the active pressure controller, self checking, suddenly noticed it was having to work harder to maintain cabin alt when nothing else had been commanded to cause it, then it would be logical for it to think a new hole had appeared in the cabin, or the controller had developed a fault. Makes sense for it to switch over to the alternate.
Seems we’re back to previous reports of noise in the vicinity of the plug (was the plug moving around?), and the unanswered miraculous coincidence (Alaska Air?) of no one being seated in the adjacent two seats.