Propeller, Two-Blade, Ground Adjustable Pitch, Metal

Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

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.