If you're there to fly for fun, as opposed to a course, then no visa required. If you're there to undertake US ratings like the FAA IR, then visa required......though of course, should your selective memory fail to mention this to the INS person, then there should be no problems. When I did my IR, they didn't ask, so I didn't tell, and everyone was happy.....come to mention it, when I did my PPL in California, I forgot to tell the INS guy too.....oops.
Cheers
EA
