Abstract: An aircraft is disclosed as having the components of a high wing airframe, a single engine of the 360 type, and a propeller formed with airfoil cross sections along the blades thereof having profiles which, when particularly matched with the designated engine and type of aircraft, result in superior performance than is available when any of the components is matched with other components. Specific disclosures of the front and rear cambers of the blades provide aerodynamic characteristics which optimize the performance capabilities of the high wing airframe in conjunction with the designated engine.

Abstract: The present invention provides a propeller or windmill blank comprising a planar sheet of material having markings defining, or being shaped to have, a central or hub region and two blades extending in opposite directions along imaginary lines; and wherein the blank has a marking or line of preferential folding inclined to the first mentioned lines which, when the blank is bent therealong, will result in pitch being applied to the blades.