Apollo -
I think you mis-spoke. This was no accident. This was mass-murder. To a dedicated suicidal terrorist, the last line of defense will be an armed flightcrew up front behind a hardened door. There is no alternative. Arm the pilots and you give them a fighting chance after the rest of the system has failed.
Quadriple checks on everything and detailed background investigations on boarding pax are impractical in the depth I think you are suggesting. And when they have failed, what will you tell my widow and children - "Your husband was very brave but still shouldn't have had the right to defend his aircraft because he couldn't be trusted with lethal force?" The only thing I worry about with armed flightcrew is if they would keep their weapons in good operational condition, considering that they would virtually never get used.
You, sir, do not have to fly everyday under this demonstrated and deadly threat. I do.
[ 13 September 2001: Message edited by: Roadtrip ]