Variable‐Pitch Airscrew Performance: A Method of Dealing with the Prediction of V.P. Airscrew Performance with Modern Supercharged Engines

IN all cases, the estimation of airscrew‐engine performance must start with a clear specification of the primary condition for which the airscrew is to be designed. In the majority of cases up to date this primary design condition has been that the airscrew is to absorb the maximum b.h.p. of the engine at maximum permissible r.p.m. at maximum boost height and maximum aircraft speed. (The aircraft speed is obviously an estimate only, but we may assume for the time being that it is reliable.) Under these conditions the airscrew efficiency is required to be the maximum possible.