I don't know if this has been posted here or not, and my apologies if it has. If it has not, please enjoy the short video of
another type of personal locomotionHere is a short clip of Franz Schoeffman flying at the German RC Academy. His helo is about 30 hp, a water-cooled go-cart engine, chain trans and simple reversing bevel gears in the can between the rotors. The rotors are a pair of ultralight props (one set with reversed pitch of course). Franz's brother runs a go-cart shop by the way.
Edited to add the information that I forgot to include about the "pilot".