There are PFA permits for homebuilts and CAA permits for ex-military types, and there may be slightly different terms, I'm not sure.
The sort of restrictions that apply, on either kind of permit... e.g.
- Mustn't ply for hire or reward
- Daytime VMC flight only
- No overflight of settlements
- No flight outside UK airspace without advance permission of the foreign airspace owner
- No instruction except to a part-owner of the aeroplane (ownership limited to a maximum 20 people)
I gather there has been some discussion lately about variations which might allow high performance ex-mil types on CAA Permits (e.g. Hunters) to fly IFR - this seems like a Good Idea providing they are suitably equipped as it would save them zooming around at high speed and low level at 2,000 feet with the rest of the PA-28 / Cessna community, they would be able to punch up thr cloud and fly on top at a respectable altitude with the rest of the pressurised jet traffic. But I don't know how far any such discussion has got, or whether it's just an idea at the moment.