Before 1914, the Oberursel Motoren Gesellschaft of Frankfurt, Germany had obtained a license to build Gnome engines. However, these pre-World War I designs became obsolete and, with the encouragement of the Army's Inspectorate of Aviation, the company embarked on the manufacture of a copy of the 82 kW (110 hp) Le Rhone engine, which became available from 1917.

Convinced of the merits of the rotary engine, aviation pioneer Anthony Fokker acquired Oberursel, and used its Le Rhone copies to power aircraft such as the Fokker Triplane and D VI scouts. Reinhold Platz designed the D-VIII cantilever-wing monoplane for Fokker around the 82 kW (110 hp) Oberursel, and attained performance equal to the best wire-braced biplanes with 50-percent more power. That aircraft was only built in small numbers at the war’s end.

This 119 kW (160 shp) Oberursel UR IIIa powered Fokker D VI, Fokker Dr I, and Pfalz D VI aircraft during World War I.

 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
Date 1917 Country of Origin Germany Type PROPULSION-Reciprocating & Rotary Manufacturer Oberursel Motoren Gesellschaft (Frankfurt, Germany)
 Physical Description Type: Rotary, 14 cylinders, air-cooled Power rating: 119 kW (160 hp) at 1,300 rpm Displacement: 23.7 L (1,443 cu in.) Bore and Stroke: 124 mm (4.88 in) x 140 mm (5.51 in) Weight: 170 kg ( 374 lb) Dimensions Other (Engine on Stand and Stand dimensions): 4 ft. 2 in. × 4 ft. 2 in. × 3 ft. 8 in. (127 × 127 × 111.8cm)
 Materials Ferrous Alloy
Non-Magnetic Metal
Unknown Coating
 Inventory Number A19340005000 Credit Line Transferred from the War Department, Air Corps, Materiel Division, Wright Field, Dayton, Ohio Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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