This may be slightly off topic here, but I would like to point out that the notion of one specific aircraft being permanently designated as "Air Force One", is incorrect. Yes, the 747 type aircraft most commonly associated with Presidential travel, is the one most often given the designation of Air Force One. However, this plane is only Air Force One when the President is actually on the plane. At any other time, it is just another military aircraft. This title is the Presidents' personal call sign, not the aircrafts'. Any plane that the President happens to travel on immediately becomes Air Force One. As F86sabre pointed out in an earlier post, the President has used corporate jets and turbo props in the past. These too, immediately become Air Force One as soon as he steps on board.
There is a television special on this very topic that has played numerous times in the past few months, and I have watched it 4 times. The narrator of the program states this fact specifically. As well, the Presidential pilot who normally flies the plane we usually see the President on, makes this same point. He is being interviewed in the cockpit, and he states that "we are waiting for the president to board the plane", and a few moments later he says "The President (speaking of Clinton) is on board, and we are now Air Force One".
This program also showed an interview with the pilot that flew the then Presidential 707, that was taking President Nixon on his last flight, shortly after leaving office. While they were still in the air, they were all (including Nixon) listening to Gerald Ford being sworn in as the new United States President. As soon as Ford had taken the oath, the pilot radioed out asking for the plane's call sign to be change from Air Force One, to SAM 27,000. He then indicated to the camera that just like that, we were no longer Air Force One, we were just another military aircraft.
If anyone gets a chance to see this program, you really should watch it. It is facinating, as it follows the history of Presidential flight, with lots of film footage of what it is like on board, flight preparations, interviewing past President Clinton, and much more. Well worth watching.