The Fokker E.IV was the final variant of the Eindecker fighter aircraft that was operated by Germany during World War I.
Anthony Fokker demonstrated the E.IV at Essen but the complicated triple-synchronization gear failed and the propeller was damaged.
The fitment of dual MG 08 "Spandau" forward-firing synchronized machine guns became the standard armament for production E.IVs, and indeed for all subsequent German D-type biplane fighters.
The modified prototype underwent combat evaluation on the Western Front by Oberleutnant Otto Parschau in October 1915, making it the first twin-gun fighter in service.
Leading German ace Oswald Boelcke evaluated the E.IV at Fokker's Schwerin factory in November.