Thank you.

The CAA (I think) is a just a statutory body that regulates movement in the air. The Warsaw Convention is the main - indeed only - treaty that governs who and how someone can be responsible if something happens when in the air.

Mister H, I may be mistaken but I thought the Warsaw Convention only applied to international conveyancing? I thought UK airspace and rules came under the CAA?

I've not been there for years. They used to hold some very good events there, including hovercraft racing. I'll possibly look into this nearer the time.

An interesting point arises about balloons.
Anyone conveyed by a balloon comes under some very, tricky legal rules. Once you become airborne by artificial means , the law as we know it ceases to apply, you become governed by what is called the Warsaw Convention. You start to bring in very complex international law and arbitration in the event things go awry.
The situation at sea in many respects is even worse. There have been quite a few cases recently of people disappearing from cruise ships on what we refer to as the high seas. This is outside the jurisdiction of any sovereign country.
I was listening to a U.S. lawyer the other night acting for some British parents who sadly lost their daughter overboard a cruise shop and he was vehemently, and quite justifiably in my view , lambasting the chaos of the high seas and how literally anything can happen with no comeback.

Looks a great event: https://www.rugbyadvertiser.co.uk/news/people/midlands-air-festival-set-return-warwickshire-venue-next-year-3042575

Something for you Rebbonk?