Originally Posted by
Goldorak
IIRC, after the code has been entered outside, someone in the cockpit has to “approve” it for the person to enter (so there is no few seconds to override the entry as this would be a big flaw in the system).
I managed to find an instruction video for Airbus aircraft:
The emergency access procedure is described from 2:30. Essentially, crew member enters the access code and unless any action is taken by pilots, doors will automatically open in 30 seconds. I don't see a flaw in this - if pilots are conscious, they can block the malicious entry during those 30 seconds.
I believe this is what happened with Germanwings - the captain has tried to use the code, but the FO overrode the request and locked the door.