Nice pics. I always thought when the President travelled that both 747s went with him, so no one is really sure which plane he is travelling on. Doesnt this happen any more ?? I know weve had cut backs, but surely not for your President..
Chris Trott can probably give you the straight skinny - but Ive only ever seen one E3 at time -- When he comes to Las Vegas - the C17s (two for the use of) land about 2 hours prior - and the F15 escorts normally go over to Nellis.
I actually learned more about the VC-25 operations (aka "Air Force 1") and the 89AW operations from National Geographic's "Inside Air Force 1" program than I did from my tour at Andrews that included their hangar (then-President Clinton was leaving as we arrived for a trip to Arizona).
The understanding I have is that both aircraft only deploy on longer flights. Stuff within the US only one plane will usually go unless there's a lot of stops then they may "pre-position" the second aircraft to be able to take over if something happens. Depending on how much travelling he's doing, there will usually be 1 or 2 C-17s (I think there was only 1 C-17 on this trip) carrying his motorcade. The second bird usually has either extra security or (more usually) a VH-60 and support equipment for if he's going to be in for any length of time. These short trips they don't need the whole setup, so they use a containerized comm center that stays on the C-17 and the suite on the VC-25 for their communication needs.
The plane that more usually "shadows" the VC-25 is the E-4B NAOC (National Airborne Operation Center), which is also based on the 747-200 airframe, that will be on station at a nearby military base (probably either Carswell or Randolph for this trip since he visited Austin and Dallas in the space of about 6 hours) in case of a military attack.