Avro 636 and 667

Staggered, single-bay biplane, 2 seat fighter trainer, it was basically a two seat variant of the Armstrong Whitworth A.W.35 Scimitar, development of which was transferred to Avro. Fuselage construction was changed to Avro's standard type of construction, being a welded steel tube structure, covered with doped fabric stretched over wooden formers, the side panels of the covering being separate detachable units to allow access to all controls. The top decking was of of sheet aluminium, with the cockpits raised above the top edge of the engine cowling, giving a "hump" to the fuselage top line in front of the front cockpit, from which the pilot's two guns projected. The wings and tail surfaces were standard Scimitar parts supplied by AWA, being built up with spars and ribs of high-tensile strip steel, and mass-balanced Frise ailerons fitted to both the top and bottom planes. The new, larger diameter propeller required an all new taller undercarriage. Two pure cantilever compression legs were both anchored at a central point in the fuselage. The legs were of large-diameter tubing, the telescopic portion of the leg being an oleo device and steel coil springs. One 420 h.p Armstrong Siddeley Jaguar IV powerplant.

Type 667 with 460 h.p Armstrong Siddeley Jaguar VIC powerplant, but typically still referred to as a Type 636.