Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer Usage Conditions May Apply Usage Conditions Apply There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page. 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An early predominant manufacturer in the United States, Spencer Heath's American Propeller and Manufacturing Company opened in Baltimore in 1909. Heath was first to use machines for mass production of aircraft propellers and, under the Paragon trademark, these were widely used in World War I. Like most propellers of that era, construction was a wood laminate because of light weight, strength, fabrication ease, and resistance to fatigue in a vibrating and flexing environment.

Heath demonstrated an "engine-powered, engine-controlled, variable and reversible pitch propeller" in 1919, but was unsuccessful in convincing the Army of the practicality of the concept. He sold the company to the Bendix Corporation in 1929 and retired from aeronautics two years later.

This propeller was designed for the World War I American Liberty engine, and could have been used on the British designed, American built De Havilland DH-4 general purpose military airplane.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Country of Origin United States of America Type PROPULSION-Propellers & Impellers Manufacturer American Propeller and Manufacturing Company
 Physical Description Type: Two-Blade, Fixed-Pitch, Wood Diameter: 305 cm (120 in.) Chord: 25.7 cm (10.125 in.) Engine Application: Liberty L-12, V-12, 300 kw (400 hp) Dimensions 3-D: 304.8 × 30.5 × 18.4cm, 27.7kg (10 ft. × 1 ft. × 7 1/4 in., 61lb.)
Storage (Aluminum Pallet): 124.5 × 337.2 × 112.7cm, 222.7kg (4 ft. 1 in. × 11 ft. 3/4 in. × 3 ft. 8 3/8 in., 491lb.)
 Materials Laminated wood, Paint, Solder, Steel
 Inventory Number A19690109000 Credit Line Found in the collection. Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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