Maybe its because I'm into airplanes as well, but I think this is the coolest "chopper" I've seen
Rotec's 7 cylinder 110HP R2800 and Rotec's 9 cylinder 150HP R3600
http://www.rotecradialengines.com/Osh/Osh.htm
Rotec's 7 cylinder 110HP R2800 and Rotec's 9 cylinder 150HP R3600
http://www.rotecradialengines.com/Osh/Osh.htm