Vickers Type 253

Vickers

Industry	Aerospace, Defence
Founded	1828
Founder	Edward Vickers
Headquarters	London , United Kingdom

The Vickers Type 253 was a two-seat, single-engine biplane designed as a versatile military aircraft in response to a 1930 government specification. Although it secured a production contract initially, this was later reassigned to the monoplane counterpart developed by the same manufacturer, the Wellesley. Ultimately, only one unit of the Type 253 was constructed.

Development

In April 1932, Vickers received an Air Ministry contract for a prototype meeting specification G.4/31, intended to replace the Westland Wapiti with a multi-purpose aircraft capable of performing level bombing, army cooperation, dive bombing, reconnaissance, casualty evacuation, and torpedo bombing roles. Vickers entered the competition with the Type 253, commonly referred to by its specification designation as the Vickers G.4/31. The Air Ministry also commissioned prototypes from other manufacturers and considered privately funded designs. The Type 253 competed against models such as the Handley Page HP.47, Fairey G.4/31, Westland PV.7, Armstrong Whitworth A.W.19, Blackburn B-7, Hawker P.V.4, and Parnall G.4/31. Favoring air-cooled engines, the Ministry saw Vickers select the radial Bristol Pegasus powerplant.

Powered by a Pegasus IIM3 engine enclosed within a drag-reducing Townend ring, the Type 253 featured a two-bay biplane design with unstaggered wings; notably, the lower wing had reduced span and chord compared to the upper wing. Both wings maintained constant chord lines but had slightly forward-swept centre sections; anhedral was present on the lower centre section extending to the inner interplane struts. The interplane struts were inclined outwardly, more pronounced on the outer pairs. Ailerons were fitted on both wings, with leading edge slats installed on the upper surfaces. Wings were attached directly to the fuselage at top and bottom with no gap; the pilot occupied an open cockpit just ahead of the upper wing's leading edge, while the observer sat well aft of the trailing edge. The tail assembly featured balanced rudder and elevators typical of conventional designs. The fixed undercarriage employed a split-axle arrangement with main legs attached beneath the inner interplane struts on the front spar and braced rearwards towards the wing roots.

The aircraft's structure comprised fabric stretched over a metal frame, but its fuselage framework was innovative for its time. Developed by Vickers' chief structural engineer, Barnes Wallis, it represented an evolution towards his later geodetic airframe concept that minimized differentiation between primary and secondary structural members. The Type 253's fuselage incorporated four light-alloy longerons constructed in sectional pieces fastened together, connected by pairs of oppositely handed helical channel members forming a diagonal tubular lattice. Wing construction was comparatively conventional and less experimental than that of Vickers' earlier Type 207, which employed thick RAF34 section wings with complex webbing inspired by Wallis' airship background; instead, the Type 253 utilized thinner RAF15 section wings built around a familiar two-spar framework.

On 16 August 1934 at Brooklands, test pilot Mutt Summers conducted the Type 253's maiden flight. Following minor adjustments, it proceeded to evaluation trials at the Aeroplane and Armament Experimental Establishment at RAF Martlesham Heath. By February 1935, it had been upgraded to use a more powerful Pegasus IIIM3 engine. The Type 253 emerged as the winner of the specification competition and was awarded an initial production order for 150 units. However, on 19 June 1935 Summers piloted Vickers' privately developed monoplane variant built to the same specification—the Type 246 monoplane prototype that would become known as the Type 287 Wellesley. This monoplane demonstrated superior performance and payload capacity immediately upon testing, leading to cancellation of the Type 253 order in September 1935 in favour of production of the Wellesley.