Hi Jim,

 

Doesn't make better sense to me, I fell off the sled with the opening statement that at zero lift the induced drag dominates, and I have a degree in aero engineering :>)  If I can remember back to aero 101 in the 50's, the induced drag is a function of lift coef. squared and would be zero at zero angle of attack. I believe the prop runs at a high negative angle of attack when it is windmilling with load and approachs the zero lift angle of attack when freewheeling. When the prop is loaded or stopped, the disk theory does not apply, it only the drag of the stick.

 

Bernie Kerr