Bit too vague, give us some more details. Or if you don't know you are clearly not welcome? Unless you are referring too RAF aircraft flying low through dinas-pass aka Mach-loop in snowdonia Wales!
RAF valley bike/track day I assume? Friend of mine goes there quite regularly, he rides an Aprillia rsv4, a bit far for me though.
If your really into airfield trackdays there are still spaces available on the RAF Shawbury on on 8/9th August. Shawbury is near Shewsbury