Spiney,
If the 9/11 Hijackings had nothing to do with the 'tools' the hijackers managed to get on board, what did it have to do with? I doubt they managed to overwhelm the aircrew with threats or a spot of harsh language...
If you do a search of these forums I think you will find that what Rockhound says is basicly correct....
Prior to 9/11 the standard response to any Hijack was for ALL crews to co-operate fully and let the Hijackers do what they wanted, as past experience showed this led to the best outcome for all concerned. You could have hijacked an aeroplane with virtually anything - and infact this did happen. The 9/11 hijackers knew this which is why they chose stuff that was, at the time, freely allowed onboard in order to take control from the crew. Nobody believed (or wanted to believe) that someone would use an aeroplane as a weapon.
The post 9/11 "Security" that we now see is just so much window dressing....and you have fallen for it.