To save time and money, the specification called for the use of a high proportion of DH.9A components, (as the RAF still held large stores of DH.9A spares), while it encouraged the use of an all-metal structure.

[2] A large number of types were tendered to meet this requirement from most of the major British aircraft manufacturers, including Westland, who submitted the design that later became known as the Wapiti.

[6] Initial tests showed poor control, and the prototype was modified with a much larger tail and horn-balanced ailerons, solving these problems.

)[7] The Wapiti performed well during RAF trials, while using significant amounts of DH.9A components, and was declared the winner of the competition, an initial contract for 25 aircraft being placed in October 1927.

The prototype Wapiti V, registered G-AAWA, was used for demonstration flights in Argentina and Uruguay on floats, powered by a 550 hp Armstrong Siddeley Panther IIA engine.

[10] It was later modified as the Bristol Pegasus-powered Westland PV-6 or Wapiti VII, re-registered G-ACBR (also known as the Houston-Wallace after the patron Lucy, Lady Houston), for an attempt to fly over Mount Everest.

Flown by Flt Lt David F. McIntyre and accompanied by a Westland PV-3 the two aircraft became the first to fly over Mount Everest on 3 April 1933.

But the northern patrolling Wapiti actually found a Japanese task force including the aircraft carrier Ryujo, and then amazingly survived to land undamaged.