Sopwith Dolphin

The Sopwith 5F.1 Dolphin was a British fighter aircraft manufactured by the Sopwith Aviation Company. It was used by the Royal Flying Corps and its successor, the Royal Air Force, during the First World War. The Dolphin entered service on the Western Front in early 1918 and proved to be a formidable fighter. The aircraft was not retained in the postwar inventory, however, and was retired shortly after the war.

Design and development

In early 1917, Sopwith's chief engineer Herbert Smith began designing a new fighter (internal Sopwith designation 5F.1) powered by the geared 200 hp Hispano-Suiza 8B. The resulting Dolphin was a two-bay, single-seat biplane. The upper wings were attached to an open steel cabane frame above the cockpit. To maintain the correct centre of gravity, the lower wings were positioned 13 inches forward of the upper wings, creating the Dolphin’s distinctive negative wing stagger. The pilot sat with his head raised through the frame, where he had an excellent field of view. This configuration sometimes caused difficulty for novice pilots, who found it difficult to keep the aircraft pointed at the horizon because the nose was not visible from the cockpit. The cockpit was nevertheless warm and comfortable, in part because pipes ran alongside the cockpit walls to the two side-mounted radiator blocks. Shutters in front of each radiator core allowed control of engine temperature.