Intended as a replacement for the Sopwith Pup,[2] the Camel prototype was first flown by Harry Hawker at Brooklands on 22 December 1916, powered by a 110 hp Clerget 9Z. Known as the "Big Pup" early on in its development, the biplane design was structurally conventional for its time, featuring a box-like fuselage structure, an aluminium engine cowling, plywood-covered panels around the cockpit, and fabric-covered fuselage, wings and tail. For the first time on an operational British-designed fighter, two .303 in (7.7 mm) Vickers machine guns were mounted directly in front of the cockpit, firing forward through the propeller disc with synchronisation gear. A metal fairing over the gun breeches, intended to protect the guns from freezing at altitude, created a "hump" that led to the name Camel.[2] The bottom wing was rigged with 3° dihedral but the top wing had no dihedral, so that the gap between the wings was less at the tips than at the roots. This was done at the suggestion of Fred Sigrist, the Sopwith works manager, in order to simplify construction. Approximately 5,490 Camels were built.[3]
Unlike the preceding Pup and Triplane, the Camel was generally considered difficult to fly. The type owed its extreme manoeuvrability and its difficult handling to the close placement of the engine, pilot, guns and fuel tank (some 90% of the weight of the aircraft) within the front seven feet of the aircraft, coupled with the strong gyroscopic effect of the rotary engine. The Camel soon gained an unfortunate reputation with student pilots. The Clerget engine was particularly sensitive to fuel mixture control and incorrect settings often caused the engine to choke and cut out during take-off. Many crashed due to mishandling on take-off when a full fuel tank affected the centre of gravity. In level flight, the Camel was markedly tail-heavy. Unlike the Sopwith Triplane, the Camel lacked a variable incidence tailplane, so that the pilot had to apply constant forward pressure on the control stick to maintain a level attitude at low altitude. The aircraft could also be rigged so that at higher altitudes it was able to be flown "hands off." A stall immediately resulted in a particularly dangerous spin.