Hovering in...
I'll take you up on that beer, I think n/rev becomes crystal clear by about the 4th, as does my grasp of particle physics....
Dave,
try searching for Ray Prouty's book at the used book web site:
<a href="http://www.abe.com" target="_blank">http://www.abe.com</a>
I also recommend Stepniewski and Key "Rotary Wing Aerodynamics" Dover press.