Abstract: A pitch control mechanism for propellers uses an elongated flat strip twisted into a helicoidal. The helicoidal is longitudinally slidable within a hollow propeller shaft. A cup-shaped cylindrical control ring coaxially mounted with respect to the front transverse surface of the propeller shaft is supported by an inner bearing ring permitting both longitudinal and rotational movement of the control ring relative to the propeller shaft. The control ring has a rectangular slot in its disc-shaped front face which fits conformally over the transverse cross section of the helicoidal. Longitudinal motion of the helicoidal therefore causes rotation of the control ring. Propeller blades are fastened to support rods terminating in downward extending, bifurcated fork-like support structures. The front tine of each fork is rotatably supported in a radial hole in the control ring, while the rear tine is rotatably supported by an axial hole in the propeller shaft.