The Westland IV and Westland Wessex were British high wing, three-engined light transport aircraft built by Westland Aircraft. In 1928, Westland began work on a small three-engined airliner, suitable for low volume, "feeder-liner" type operation, as a follow-on to its single-engined Westland Limousine transport. The new type was known as the Limousine IV early in development, which soon became the name Westland IV. The Westland IV was a high-winged monoplane with a mainly wooden structure. The fuselage was of square section and built around spruce longerons and ash frames, with internal wire bracing and fabric covering. The wings had wooden box spars and spruce wing ribs in a Warren girder arrangement, and were braced to the fuselage by streamlined struts. The aircraft had a fixed tailwheel undercarriage. The Westland IV first flew on 21 February 1929 at which time it was powered by the 95 hp (71 kW) Cirrus engine. This prototype was registered as G-EBXK and was certified for a crew of two and four passengers. The second machine had Hermes engines and a metal rear fuselage. The third machine, G-ABAJ, was modified to take the 105 hp (78 kW) Armstrong Siddeley Genet Major engines as well as some other changes and became the prototype Westland Wessex. The two Westland IVs were subsequently converted to Wessexes giving 10 aircraft in total.
