Overflying instrument approach tracks

[PelicanSquawk]

Hi there,

Is there a safe height one can overfly an instrument approach track? And is there a procedure for gaining permission?

The reason I ask is because I am planning a VFR flight into Duxford from the north, and it’s very close to Cambridge airport with an approach track. I could just stay on the radio to Cambridge and ask permission, although i’ll probably need to be talking to Duxford at this point. The joining instructions are such that it’s awkard to totally fly around the track.

Any my specific advice on Duxford appreciated, and general advice to do with instrument approach tracks.