Designed for the postwar civil market, the Gnu was a conventional equal-span biplane. It had an open cockpit for a pilot with seating for two passengers under a hinged and glazed roof. Most of the aircraft were powered by a 110hpLe Rhône rotary engine. The enclosed passenger cabin was cramped and unpopular and most production aircraft had an open rear cockpit. One prototype and twelve production aircraft were built. A postwar slump ended production and the company had problems selling the aircraft although two aircraft were sold in Australia.
The United Kingdom-based aircraft were mainly used to provide joyrides in the early 1920s. Two aircraft that were used for exhibition and stunt flying in the late 1920s crashed. Most of the production aircraft were not sold and were dismantled, including four aircraft that remained unsold when the Sopwith Aviation Company folded in 1920. Two Australian aircraft were used by Australian Aerial Services Limited on the Adelaide to Sydneymail route.