Originally Posted by
DaveReidUK
Are we, perhaps, seeing the difference between a cabin depressurisation following, say, a window blowing out, and the effect of a hole suddenly appearing that's many times the size of a window?
The end result will be the same - a cabin at ambient pressure - but the time taken to get to that point will almost certainly vary. What rate of decompression are cockpit door blowout panels intended to cope with?
If there are vents into the cockpit to equalize with the avionics bay, then the only way out for the avionics air may be by opening the cockpit door. The last time a large event like this happened (Aloha Air**) it pre-dated the locked door requirement so maybe it wasn't revisited by the systems architects to ask what happens to all of that. It may be that the additional expansion from below the floor is the source of the air that blew the checklist and pilot headphones around.
Does the door even have blow-out panels? They may have been disabled to prevent terrorist access.
It's around 10 psia outside at 16k feet, so if fully pressurized to 15 psia that is only a 50% expansion - the volume of air in the cockpit and the area below the cockpit to be expelled is 50% of the geometric volume. The greatest pressure is 5 psi; ~20 inch X 70 inch door = 7000 lbs, or 3500 pounds on the latch. I would bet the latch is fine and the door simply flexed enough to disengage. The energy stored in the flex might be what damaged the lavatory door from arching back the other way when the latch slipped.
(edit) **I forgot about the crown blowout; that must have been after 9/11. It may not have been as large as this but it was close.