When President Fowler is getting on his VC-25A (usually known as Air Force One), you can see the number on the tail-- its a 4 digit number. I can't remember the specific one used in the movie, but every presidential airplane since at least Kennedy's presidency has been 5 digits long. There has been a 26000, 27000, and now 28000 and 29000. 28000 and 29000 are the numbers of the two VC-25As often used by the President as Air Force One.