The Friedrichshafen FF.31 was a German lightweight two-seat floatplane of the 1910s produced by Flugzeugbau Friedrichshafen. Development and design The FF.31 was a biplane floatplane with a central nacelle and two open cockpits. The engine was mounted at the rear of the nacelle, driving with a pusher propeller. The twin open-frame tail booms extended aft from the wings to carry the tail unit. A version of the FF.31 with a fixed tailskid landing gear was designated the FF.37. Operational history FF.31s took part in a Sea battle where the German Imperial Navy was defeated, in May 1915. Variants FF.31 Production floatplane FF.37 FF.31 with fixed tailskid landing gear. Operators German Imperial Navy Specifications (FF.31) See also References Bibliography Further reading 1910s German military reconnaissance aircraft Single-engined pusher aircraft Floatplanes Biplanes Twin-boom aircraft FF.31 Aircraft first flown in 1915