This propeller was invented by the donor, Ernest G. McCauley, manufactured by his company, and was the first solid steel propeller used by the U.S. Army Air Corps. It has an adjustable pitch, and a concave-convex shape to improve rigidity. The design was conceived in 1931, with the objective of saving weight. Using high tensile strength steel, a very thin airfoil section could be utilized. The toughness of steel allowed ready forging of blades into an approximate shape, with final bending, twisting, and straightening in the manufacture.
An experimental propeller was sent to Wright Field, Dayton, Ohio, for testing in late 1932. Tests by the Army Air Corps in 1933 demonstrated increased performance in take-off, climb, and speed, resulting in its acceptance by the U.S. Government. It was made standard equipment for the Stearman Primary Trainer, and used by both the Army and Navy from 1936 until the end of World War II in 1946.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
1933-1946
United States of America
PROPULSION-Propellers & Impellers
McCauley Industrial Corp.
Type: Two-Blade, Ground Adjustable Pitch, Metal
Engine Application: Continental R-670-5, 164 kw (220 hp)
3-D (Propeller): 218.4 × 19 × 15.9cm, 24.9kg (7 ft. 2 in. × 7 1/2 in. × 6 1/4 in., 55lb.)
Storage (Aluminum Pallet): 314.3 × 121.9 × 124.5cm, 284kg (10 ft. 3 3/4 in. × 4 ft. × 4 ft. 1 in., 626lb.)
HAZMAT: Cadmium Plating
Steel
Preservative coating
A19580111000
Gift of Ernest G. McCauley
National Air and Space Museum
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