Thanks for replying,
I agree with you re; the visa stuff. I'm determined to get everything above board, The US immigration take a very dim view of any chancers and obviously I want to avoid that. It's just that Hour building falls into a gray area, I'm not under taking a course of study, I'm not gaining any certificate from what I'll be doing either in the states or anywhere else.
A mate of mine did fixed wing hour building in Florida in 2013 and they made him show his logbook at immigration because they didn't believe him, but once he had shown them it they left him off. He went in on the visa waiver program.
I'm 100% sure that I'm PIC. I'm rated on the R44 but thinking of doing the Robinson safety course in the R22 as preparation for hour building. It's the cheapest hourly rate by some distance.