At the Paris Air Show today I was talking to a person who has reason to be interested in the loss of AF447, and she raised an interesting point: did the fact that the cockpit door is a post-9/11 security door make a material difference to the time it took for the captain to re-enter the flightdeck after the accident sequence had begun?
The BEA (the French accident investigation agency) may be able to determine the answer, and if they can, they will reveal it in the accident report.
Maybe even if the door did NOT delay the captain's re-entry the accident would have happened anyway, but there are a few hints - among the currently incomplete summary of what the pilot flying was doing with the controls - that, shortly after the captain's arrival, the pilot flying momentarily changed his attempted recovery tactics in a way that might have been successful if he had maintained the change.
Whatever we ultimately find out about this from the BEA's investigation, it is a valid time to review whether the cockpit security door is a net safety benefit or disbenefit. In less than three months it will be the tenth anniversary of 9/11. Maybe the aviation industry should use the occasion to review all the changes, on the ground and in the air, that were adopted in the immediate aftermath of that truly shocking event.