Claire,
First off your friend will need the right to work in USA (visa/citizenship, etc.).
There are really no sponsership type stuff in the states, but if your friend is looking for an unsecured loan for flight training they could try the SLM Financial Corp. Phone No. 1-800-559-3220. Be warned, however that the interest rate could be somewhat high as I am currently paying about 14% on 20,000.00USD. And, of course, a job that pays enuf to live on and make the payment.
Good Luck,
USF