Originally Posted by
Jonty
it’s impossible to open a door against a fully pressurised cabin. So can a cabin door be opened inflight? Yes, but only in very specific circumstances. In normal cruise flight, at cruise altitude, it’s impossible.
It would be more accurate to say that it's impossible to open a door
that initially moves inwards against a fully pressurised cabin, for obvious reasons.
Doors like those on narrow-body Airbuses, that move upwards and then outwards, are subject to different considerations. It may be that cruise diff pressure is sufficient to prevent the upwards movement of the door, but I wouldn't want to bet on that. Nor, presumably, would Asiana.