Kerry covered that one dead on.
Now that the question has been answered. How about a highjack to some trivia that came to mind along this same issue.
Did you know that in forward flight (fast). There is a length of a helicopters rotor blades, where the air is actually flowing backwards across the blade surface?
Things that make ya go: Hmmmmm.
Or maybe they just make ya go: Who gives a ...?
