In their search for an outstanding fighting aeroplane the Sopwith experimental department decided in early 1916 to build an entirely new design--a triplane. The completed machine had three narrow-chord wings. The combined wing area of the three mainplanes gave the aircraft plenty of lift. Ailerons were fitted to all three wings; the interplane struts were plain but strong and few bracing wires were needed. The fuselage was a typical Sopwith wooden box girder. Tail- plane, elevators, rudder and fin resembled those of the Pup , but later production models had a tail-plane of reduced area. The handling qualities of the Triplane were excellent. It is now regarded as only slightly less manoeuvrable than the Pup, but many pilots preferred it to the little biplane.