Originally Posted by
goalie
Too bad for the hijackers

but sadly imho, there will be another 9/11 (tho I sincerely hope not) but it won't be via the use of an airplane
Member of the Flight Deck Officer Program takes his gun, shoots their fellow pilot after take off, declares and emergency and in the confusion flies plane into building - even if the rest of the crew know what's happening they can't do anything about it as the door is locked