Hi Drew,

I don't see the benefit of your proposal over a very sturdy door which might be tied into the controls (via simple switches, etc.) to prevent it from being opened once the plane leaves the gate (even if the pilot wants to).

(This does open the door, so to speak, for attacks when the plane is being loaded with passengers, or when the flight crew changes, etc., and the flight deck door is open. But there may be operational ways to mitigate these issues.)

And there's the tradition that the pilot is the master of the plane. It's his/her responsibility for it to be operated safely. I don't think that aspect of the pilot's job should be handed to people on the ground.

Cheers,
Scott.