Vickers Wellesley
The Wellesley was a single-engined medium bomber built by Vickers-Armstrongs, and the first production aircraft to use Barnes Wallis's geodetic construction, in which a lattice of light members carried the loads. Developed for the Air Ministry's G.4/31 general-purpose requirement — a contest Vickers' biplane Type 253 won before the order was switched to the monoplane — it first flew on 19 June 1935 and entered RAF service in 1937; 177 were built in all. In November 1938, Wellesleys of the Long Range Development Unit set a world distance record with a non-stop flight from Egypt to Australia. Already obsolete for the European war by 1939, the type fought against Italian forces in East Africa and flew maritime patrols from the Middle East until 1942. No example survives.
Why It Mattered
The Wellesley was the first aircraft produced for the RAF with Barnes Wallis's geodetic construction, an airframe built as a light grid of simple parts whose strength lay in the whole lattice rather than in a few heavy members. It reached production by an odd route: the Air Ministry's 1931 specification for a general-purpose aircraft was won by Vickers' biplane entry, yet in September 1935 the production contract was switched to the company's fully geodetic monoplane instead. In November 1938 the type made its public mark, when Wellesleys modified for long-range work with the RAF's Long Range Development Unit flew non-stop from Egypt to Australia and claimed the world long-distance record. Its lasting importance is structural: tests on the Wellesley proved the geodetic method, and Vickers carried the same structure into the Wellington, one of Bomber Command's mainstay aircraft of the Second World War.
Design Notes
Wallis's geodetic airframe was a lattice of light, simple parts under a fabric skin, its loads shared across the whole grid, which made the structure light for its strength. Nobody knew how such a structure would stand being cut into for a bomb bay, so the Wellesley carried its bomb load outside the fuselage, in a streamlined pannier slung under each wing. Power came from a single Bristol Pegasus XX radial of 925 hp; the wing was unusually long and narrow, with an aspect ratio of 8.83, and the undercarriage retracted only by hand. The crew of three sat in two cockpits; on the version unofficially dubbed the Mk II, the pilot's canopy was extended aft over the navigator and bomb-aimer's position, which in the Mk I had been buried in the fuselage.
Operational History
The monoplane prototype first flew from Brooklands on 19 June 1935, the first production Wellesley followed on 30 January 1937, and the RAF received its first aircraft that April. Production totalled 177 aircraft, and at its peak the type equipped six squadrons of RAF Bomber Command in Britain. On 5 November 1938, three of the long-range aircraft set out from Ismailia in Egypt; two reached Darwin, Australia, after a non-stop flight of 7,162 miles (11,526 km), a new world distance record, and the third, though it also broke the record, landed in West Timor 500 miles short of the objective. By the start of the Second World War the Wellesley was already considered obsolete and unsuited to the European air war, and its remaining service lay overseas, in East Africa, Egypt and the Middle East. From June 1940 the overseas squadrons bombed Italian forces in Eritrea, Ethiopia and Somaliland, forming a major part of the Commonwealth bomber forces in that campaign, and the type stayed in use against the Italians until November 1941. The final Wellesley unit, No. 47 Squadron, then flew maritime reconnaissance and anti-submarine patrols; it ended its use of the type in September 1942, although one of its flights kept a Wellesley on patrol until March 1943.
Afterlife
No Wellesley survives. The nearest thing to a survivor the sources record is a single component: a bomb pannier from a Wellesley, on which restoration work began in France in 2004. Of the record-flight aircraft, the one damaged in Australia was dismantled and shipped home, allotted to a maintenance unit as Instruction Airframe 1856M, and never flew again. What the type left behind was its construction: the geodetic structure it proved in service passed to the Wellington, and the distance record it set in 1938 stood unbroken until November 1945.