I just want to know who had the raisens to teach you a 15' hover auto in a R22. Being with students in a 2' hover (for practice hover autos) ive had troubles before getting the helicopter nice and level and a good pull that it felt good. At 3' they would be much rougher but the 22 could probably take it. At 5 feet you just spread the skids. At 10 feet you are going to the hospital if for nothing else than to get the chunk of seat that your ass just ate out. At 15 feet your penis no longer salutes the hot chicks admiring your speed demon wheel chair.
Stay at 3' and just look where you are going. To teach hovering, find a better place that is nice and open and clean and stay at 3'.
Side note- Why ignore the HV curve that guys like Rich and Nick bust their ass to make? Sorry if any of the other members are test pilots and I left them off, I for one appreciate you doing much of the dirty work for the helicopters I fly.