There are drugs you can take if you are insecure about the size of your manhood. Airport security, metal detectors, invasion of privacy, etc all to prevent a deadly weapon getting on board the aircraft, then you go and give a gun to a wannabe hero with zero military or law enforcement experience and let him take it on board the aircraft.
Talk about a post 9/11 knee jerk reaction from the Bush administration.
Pilots have enough liability. Why add to it by being responsible for a firearm too?
Stupid idea.