Thomas Dicks, an English émigré, founded the Dicks-Luttrell Propeller Company in 1918 with a Westinghouse co-worker. Reorganization by Pittsburgh entrepreneurs resulted in creation of the Standard Steel Propeller Company, which was eager to receive an Army contract for an early experimental controllable and reversible-pitch propeller. Collaboration with the Army's Engineering Division began in 1919. Mechanical hub design was attributed to Dicks, who received the assistance of the Army's Frank Caldwell, a leading propeller designer of the early 20th century.
This highly significant artifact; a predecessor to the modern variable-pitch propeller, was the first design to employ counterweights. Built for the Liberty engine and DeHavilland DH-4 aircraft, the Dicks-Caldwell design appeared satisfactory from the standpoint of mechanical engineering after considerable development, but its excessive weight made it prohibitive. Standard Steel abandoned the design of a variable-pitch mechanism in 1923 and continued its specialization in the construction of metal blades in direct cooperation with the Army.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.