The Heston T.1/37 or
Heston JA3 was designed under the leadership of George Cornwall to meet UK
Air Ministry Specification T.1/37 for an
ab initio trainer, and was otherwise unnamed. Its competitors were the
Miles M.15 and the
Parnall 382 (Heck III). The
Airspeed AS.36,
General Aircraft GAL.32 and
Percival P.20 were also proposed against specification T.1/37, but not accepted for being built as prototypes. None of the designs was selected for production orders; it has been suggested that the required performance could not be achieved within the constraints of the Specification. Construction was primarily wooden, with plywood-skinned spruce frames, open framed movable flying surfaces, some
monocoque sections, all fabric-covered. The cantilever oleo-pneumatic fixed main undercarriage legs were raked forward and faired with spats, and the tailwheel was also spatted. The propeller was a
de Havilland fixed-pitch type, later replaced by a two-speed type in 1939 when other modifications were made at Heston. Student and tutor sat in open, tandem cockpits. ==Operational history==