US resident , no greencard, buying a glider in the US

You just have to get creative without making it complicated. Here are
some ideas:

These should occur concurrently:
1. Lend the purchase money to a US citizen for 1 dollar in interest a
year, who then buys the plane in his/her name
2. Lease it back from him or her for 1 dollar a year with an option to
buy it in exchange for canceling the loan. Yo also have a right or
first refusal in he/she tries to sell. The agreement will also
stipulate that if he/she sells before you exercise the option, that
you receive the sales proceeds.
3. In the lease agreement, you also agree to assume all liabilities,
taxes, insurance, maintenance etc...while you operate it
4. When you sell, you
a) buy it back by canceling the loan
b) sell it concurrently with the purchase without registering it in
your name

Corporation
I think a US corporation needs a social security number to be attached
to it to start it. But later, I think a foreigner can "buy" it out
100%. You can do it that way as well I think and run everything under
the corporation. You'd need to file yearly corporate returns. If it's
just for the glider, the extra work paperwork for taxes would be
minimal.

Register in UK and fly in USA

Good luck