Fokker V.7

The Fokker V.7 was a prototype fighter triplane designed by Fokker-Flugzeugwerke during the First World War for the Imperial German Army's Air Service, an attempt to improve on the Dr.I by using larger and more powerful rotary engines than its standard Oberursel Ur.II. Four aircraft were built in 1917, each with a different engine, and none of them made it into production. The first was ordered on 13 August 1917 with an experimental 11-cylinder 153 kW Siemens-Halske Sh.III double-acting rotary, in which the crankshaft rotated one way and the crankcase the other, and was designated V.7S; to use the higher power and revolutions it tested two- and four-bladed propellers of larger diameter, which required longer landing gear and a lengthened rear fuselage. Flight testing continued into January 1918. The V.7O, begun on 23 August 1917, had a 14-cylinder 120 kW Oberursel U.III, which proved little improvement on existing engines, and it was converted into a Dr.I accepted on 26 April 1918.