[Crispy]

I am a computer programmer and I don't think I would want my life in the hands of such a system.

I think a better method is to totally isolate the pilots in the cockpit for the whole flight. Nobody allowed in period. Crew members could communicate with the pilots through an intercom in the crew area.

[Hank Rearden]

Crew members have to eat. Crew members have to pee.

And your "solution" doesn't address the psychology of a hijack. If the flight crew is hearing their friends and their passengers being executed one by one just outside their "impenetrable" door, how long do YOU think they could hold out?