Well that makes a bit more sense then.
So the problem is not with the US company registering for VAT in the UK, and claiming it back. The problem rests with the fact that the US company can not own the aircraft, unless it spends >6 months in the US.
I fully accept that a trust owning a number of aircraft for different owners is a different vehicle altogether. Clearly such a trust would find it very difficult to manage a trading activity in the UK. And even if it did, it would have difficulty returning the benefit of the VAT claim to the beneficial owners of the aircraft.
However having said all that, it should still be possible, with the trust company's support, to set up the appropriate leasing structure to have the VAT interest in the aircraft in the UK. Though once again, any sales would be liabile to VAT.
dp