A few years ago I sat next to the in flight security officer. We were in coach, and he didn't take off his jacket the entire flight.

At the end of the flight, he turned to me and said, "Mr. X, have a great stay in Israel" and reached up to get his duffel bag. That's when I noticed he was carrying a gun. Of course, I also hadn't given him my name during the flight, which he knew.

Also, it's not actually true that they have two armed marshalls on all flights -- one FA and one passenger. Almost ALL of their FA's are ex-commando or ex-paratrooper (two of the three most "elite" units of the Israeli army). And they usually have more than one passenger planted.