Originally Posted by
Jimmy.
Crab,
Ray Prouty, on a chapter about forward performance, discusses the profile power (used to overcome friction drag on the blades) and give 15% to 40% of the main rotor power in hover values as a reference. He also states that this value is "fairly constant" as the airspeed increases "until at high speed when blade stall or compressibility, or both, rear their ugly heads. At this point, the profile power inceases and usually becomes the dominant component." (Helicopter Aerodynamics, vol 1, p. 111)
Sounds good to me Jimmy - if Ray says it is so then it is so
