Fantastic idea. I wonder if this has been forwarded on to the FAA? Thanks for the post!
One of the engineers I work with came up with a similar idea. Hit a hidden button, and all flight data is locked. The airplane is then on automatic pilot with the initial course information that was plugged it. It can only be unlocked from the Air Traffic Control Tower via transponder code. Navigation via GPS. Any idiot who tries to hijack the aircraft once the button is hit, is just fooling with instruments that do not respond.
Also, retrofit the aircraft to have a SOLID bulkhead between the passengers and the pilot. Insert a special hatch for the pilots only to use.
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.