This controllable-pitch propeller, one of the first produced by Hamilton Standard, represented a major advance in aircraft technology in the early 1930s. It allowed a pilot to adjust the propeller blade's pitch to provide the best performance at different air speeds (similar to changing gears in a car or on a bicycle). On takeoff the pilot chose a lower pitch to make the blade spin faster and provide maximum power. In flight the pilot switched to a higher pitch to make the blade spin slower and conserve fuel.
This particular propeller was from a Lockheed Vega airplane owned by the Crosley Radio Corporation and flown by Ruth Nichols. Flying in that airplane in 1931-32, Nichols became the only woman to hold simultaneously the women's international speed, altitude, and distance records for flight. She set the distance record in October 1931 when she flew 1,977 miles between Oakland, California and Louisville, Kentucky. Nichols' records proved the effectiveness of the new controllable-pitch propeller.
This very special propeller is on display in the Pioneers of Flight Gallery at the National Air and Space museum in Washington DC.
This 4-blade propeller was made by De Havilland Airscrews, under licence from Hamilton Standard, probably for fitting to a 4,000-horsepower (3,000-kilowatt) Rolls-Royce Tyne turboprop engine. Four Tyne engines powered the Vickers Vanguard airliner and Merchantman freighter. These aircraft were in service between 1961 and 1996.