Conversely, as a hijacker, you'd be taking a huge gamble to try and select the one flight where there were no air marshals.
A lot of times, I feel like this whole concept was based on an inherit deterrent and seems to have worked, in conjunction with increased airport screening:
"The number of hijackings has dwindled in recent years. About 50 have been reported since Sept, 11, 2001, and none in the U.S., according to the Aviation Safety Network."
Reinforced cabin doors and knowing that the terrorists want to kill everyone instead of taking hostages has changed the game. I'm not privy to what influences terrorists but it seems like they can no longer commandeer airplanes
If you're going to be hijacking to use the plane as a weapon you aren't going to be worried about the 1 in 10 chance of an air marshall trying to stop you, any more than the near certain attempt of the other 200 people on the plane trying to stop you. There just aren't legions of people out there willing to kill massive amounts of people in this fashion.
The number of bear attacks in Springfield went to zero in 1996 when Homer started Bear Patrol. It's a case of life imitating art.
Before 9/11 you hijacked a plane, flew to Cuba, got some money, and all was well.
Before 9/11 you were a passenger/crewmember on a plane, you flew to Cuba, then got released, and all was well.
9/11 changed that. No longer were passengers and crew safe as long as they complied, no longer were planes allowed to fly around and even be refuelled safe in the knowledge that all it would take is some money to free them.
As such over the course of two hours the calculus changed. Hijacking the first 3 planes worked because nobody expected it. The fourth plane was also hijacked, but the goal (crashing into whatever building) wasn't met because the passengers and crew found out the rules had changed.
If you hvae 5 people willing to kill themselves for your cause, there are better ways to make a political statement now than the risk of hijacking a plane - not because of any potential air marshall, but because of the guarantee of the passengers.
