The Vickers Wellesley was a medium bomber that was designed and produced by the British aircraft manufacturer Vickers-Armstrongs at Brooklands near Weybridge, Surrey. It was one of two aircraft to be named after Arthur Wellesley, 1st Duke of Wellington, the other being the Vickers Wellington.
The Wellesley was developed during the early 1930s in response to Specification G.4/31. The biplane Vickers Type 253 was effectively an early incarnation of the aircraft, sharing its radical geodesic airframe and many other features. The Type 253 was determined to be the best submission received by the Air Ministry, thus an order for 150 production aircraft was issued. As a private venture, Vickers has also developed the monoplane Type 256; following flight testing of this aircraft, the order placed for the Type 253 was converted for the Type 256 instead.
The vast majority of the Wellesley's production run were supplied to the Royal Air Force (RAF), a total of six squadrons under RAF Bomber Command operated the type at its peak. A high-profile demonstration of the aircraft's capabilities was conducted during early November 1938 via a flight of three Wellesleys that flew non-stop for two days from Ismailia, Egypt to Darwin, Australia, a distance of , setting a world distance record in the process. While the type was considered to be obsolete by the start of the Second World War and thus unsuited to the European air war, the Wellesley was operated overseas in the desert theatres of East Africa, Egypt and the Middle East. The final Wellesley-equipped unit, 47 Squadron, ended its use of the type as a maritime reconnaissance aircraft, during September 1942.
Design and development
Background
The Wellesley's origins stretch back to the early 1930s, during which time Vicker's management were making great efforts to secure more business in the fixed-wing aircraft sector following the decision to discontinue airship production. Several of its designs around this period, often made in response to various specifications issued by the Air Ministry, revolved around a conventional biplane configuration, albeit larger than most contemporaries and being fitted with more powerful engines to match. While some of these proposals never went beyond the drawing board, they often harnessed the work of Barnes Wallis to save weight without compromising on strength by using light alloy structures.
During 1931, the Ministry released Specification G.4/31, which called for a general purpose aircraft that was capable of carrying out level bombing, army co-operation, dive bombing, reconnaissance, casualty evacuation and torpedo bombing. Vickers quickly took an interest in the requirement and gave its design team the task of producing its response. The team devised three separate conceptual aircraft, two being monoplanes with alternative engines fitted, and the third being a biplane design, known as the Vickers Type 253. Following the submission of these three design outlines to Air Ministry in November 1931, it accepted the Type 253, and issued an initial development contract to Vickers during April 1932.
Even as work proceeded on the construction of the Type 253 prototypes, Vicker's design office continued to independently work on a monoplane submission to fulfil the specification. This aircraft incorporated a geodesic airframe, which had been derived from Wallis' earlier work for the airship R100. According to aviation author C. F. Andrews, this design choice was a radical shift from established practices of the era, which had been virtually unchanged since the First World War Wallis pursued this as it enabled substantial weight savings to be made via unheard of strength-to-weight ratios. The Type 253 also incorporated some of this structural design, but not to the full extent of the in-development monoplane.
Following their delivery, the Type 253 prototypes were subject to competitive testing of their fulfilment of the specification's various criteria against a range of competing aircraft, including the Fairey G.4/31, Westland PV-7, Handley Page HP.47, Armstrong Whitworth A.W.19, Blackburn B-7, Hawker P.V.4 and the Parnall G.4/31. From this, it was recognised that the Type 253 was the best submission, leading to Vickers receiving an order for 150 aircraft.