FlyingSquirrel,
I and several others have done it, but you will need to put it through a company in the sense that you tell them you're a helicopter pilot, a sole trader. Any half-decent accountant will tell you what to do, though you might have problems getting them to believe that it's possible to claim VAT on training. There's also a VAT helpline; I can't remember the number, but again, an accountant should have it. Once it's set up you can easily do it all yourself, so you'll only have to pay an accountant's fee the once.
