We had a pilot who flew for us during the late 1980's that had taught himself to fly helicopters. He had worked for Cessna as a new plane delivery pilot and as a crop duster accumulating many thousands of hours and decided that he wanted a new challenge. He bought a Hiller UH-12 (not sure which model) and proceded to learn how to fly it. By his own account everything went fine until a gust of wind pushed him up and across his fence onto a neighbors property. He got it down ok but after the experience wasn't sure he wanted to try again so he hired a commercial pilot to return the helicopter to his proper and continued teaching himself to fly. By the time he worked for us he had over 8000 hours of helicopter time.