A couple years back I was part of a team exhibiting an ex ATC Slingsby Sedbergh (T21) at Fairford. Because we'd brought an aircraft (albeit on a trailer!) we were issued with big "Aircrew and Groundcrew" passes.
We had to get there early both days to rig the glider and on the Sunday I arrived at about 0600. With the pass I was allowed straight in and there was just me on the airfield with about a zillion pounds worth of hardware. Now
that was an experience and I have the photos to prove it!
The pass also got me half an hour unaccompanied inside the BBMF Lancaster.
So my advice is, if you're going to Fairford, take an aircraft with you! (even a T21!)