Fokker V.4

The Fokker V.4 was a prototype German fighter triplane built for the Austro-Hungarian Imperial and Royal Aviation Troops during the First World War. It began as a biplane, but was changed to a triplane after Anthony Fokker learned what a positive impression a British triplane had made on German fighter pilots. Fokker had received an order for a fighter biplane using a 82 kW Oberursel UR.II rotary engine on 13 May 1917, and after returning from a long visit to the front on 13 June, where pilots including Manfred von Richthofen had been greatly impressed by the Sopwith Triplane, he ordered Reinhold Platz to change it to a triplane. By then the company had designed a second version of its cantilever wing with a much lighter hollow double box spar and plywood only on the leading edge, and the fuselage reverted to the slab-sided form of his first fighters, which improved lateral stability and the pilot's downward view. It was shipped to Hungary for evaluation in 1917.