Vickers Type 253
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The Vickers Type 253 was a single-engined two-seat biplane general-purpose military machine built to a 1930 government specification. It won a production contract, but this was transferred to the same company's monoplane equivalent, the Wellesley. Only one Type 253 was built.


Development

In April 1932 the
Air Ministry The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...
awarded a contract to Vickers for a single prototype aircraft under
Air Ministry specification This is a partial list of the British Air Ministry (AM) specifications for aircraft. A specification stemmed from an Operational Requirement, abbreviated "OR", describing what the aircraft would be used for. This in turn led to the specification ...
G.4/31 for a
Westland Wapiti The Westland Wapiti was a British two-seat general-purpose military single-engined biplane of the 1920s. It was designed and built by Westland Aircraft Works to replace the Airco DH.9A in Royal Air Force service. First flying in 1927, the Wa ...
replacement, a multi-role aircraft capable of carrying out level bombing, army co-operation,
dive bombing A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact throughou ...
,
reconnaissance In military operations, reconnaissance or scouting is the exploration of an area by military forces to obtain information about enemy forces, terrain, and other activities. Examples of reconnaissance include patrolling by troops (skirmisher ...
,
casualty evacuation Casualty evacuation, also known as CASEVAC or by the callsign Dustoff or colloquially Dust Off, is a military term for the emergency patient evacuation of casualties from a combat zone. Casevac can be done by both ground and air. "DUSTOFF" is ...
and torpedo bombing. Vickers' entrant to this competition was the Type 253, though often known by the specification as the Vickers G.4/31. The Ministry had also ordered prototypes of other designs and some manufacturers had offered private ventures (aircraft built with their own money). The Type 253 was in competition with the Handley Page HP.47. Fairey G.4/31,
Westland PV.7 The Westland PV.7 was a private venture submission to a 1930s British specification for a general-purpose military aircraft with two crew. It was a single-engined, high-wing monoplane of promise, but was destroyed early in official tests. Desi ...
,
Armstrong Whitworth A.W.19 The Armstrong Whitworth A.W.19 was a two/three-seat single-engine biplane, built as a general-purpose military aircraft in the mid-1930s. A newer, monoplane aircraft was preferred and only one A.W.19 was built. Development Multi-tasking "gene ...
,
Blackburn B-7 The Blackburn B-7 was a single-engine two/three-seat biplane built to a United Kingdom, British Air Ministry specification for a general-purpose, multitasking aircraft. It first flew in 1934, but no contracts were issued and only one aircraft w ...
,
Hawker P.V.4 The Hawker P.V.4 was a 1930s British biplane aircraft built by Hawker Aircraft in competition for a government order for a general-purpose military aircraft. Design and development In 1931, the British Air Ministry issued a their Specification ...
and the Parnall G.4/31. The Ministry preferred an air-cooled engine, and Vickers' choice was the radial
Bristol Pegasus The Bristol Pegasus is a British nine-cylinder, single-row, air-cooled radial aero engine. Designed by Roy Fedden of the Bristol Aeroplane Company, it was used to power both civil and military aircraft of the 1930s and 1940s. Developed from t ...
. The Vickers Type 253 used a Pegasus IIM3 engine, enclosed by a drag-reducing
Townend ring A Townend ring is a narrow- chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling. Development The Townend ring was the invention of Dr.  Hubert Townend of the British National Physica ...
, to power a two-bay, unstaggered biplane, with a lower wing smaller in span and chord. Both wings were of constant chord, but the centre sections were mildly forward-swept and the lower centre section carried anhedral out to the inner interplane struts. Both sets of interplane struts leaned outwards, the outer ones more so. Both wings carried ailerons and the upper planes had
leading edge slats Slats are aerodynamic surfaces on the leading edge of the wing of a fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, ...
. The wings joined the fuselage top and bottom with no gap, the pilot sitting just ahead of the leading edge in an open cockpit and the observer sitting well behind the trailing edge. A conventional tail carried balanced rudder and elevators. The split-axle fixed undercarriage was neatly mounted, the main legs fixed to the front spar under the inner interplane struts and braced rearwards to the wing roots. Construction was the common one of canvas over a metal frame, but the fuselage frame was quite novel. It was designed by Vickers' chief structural engineer,
Barnes Wallis Sir Barnes Neville Wallis (26 September 1887 – 30 October 1979) was an English engineer and inventor. He is best known for inventing the bouncing bomb used by the Royal Air Force in Operation Chastise (the "Dambusters" raid) to attack ...
and was a step along the road to his
geodetic Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equivale ...
frames, where the distinction between main and secondary members was largely lost. The Type 207 fuselage frame had four light-alloy
longerons In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...
, each made in sections that were screwed together. These longerons were joined by a pair of oppositely handed helical channel members, forming a diagonal tubular mesh. Wing construction was less radical, and indeed less novel than that of the earlier Type 207, which had thick
RAF The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...
34 section wings built of complex webbing informed by Wallis' earlier airship experience; the Type 253 reverted to the thinner RAF15 section and a more familiar two spar design.
Mutt Summers Captain Joseph "Mutt" Summers, (10 March 1904 – 16 March 1954) was chief test pilot at Vickers-Armstrongs and Supermarine. During his career, Summers flew many first flights on prototype aircraft, (a record of 54 by a test pilot), from the Su ...
took the Type 253 on its first flight on 16 August 1934 at
Brooklands Brooklands was a motor racing circuit and aerodrome built near Weybridge in Surrey, England, United Kingdom. It opened in 1907 and was the world's first purpose-built 'banked' motor racing circuit as well as one of Britain's first airfields, ...
. It then went, after some modifications to the
Aeroplane and Armament Experimental Establishment The Aeroplane and Armament Experimental Establishment (A&AEE) was a research facility for British military aviation from 1918 to 1992. Established at Martlesham Heath, Suffolk, the unit moved in 1939 to Boscombe Down, Wiltshire, where its work ...
at
Martlesham Heath Martlesham Heath village is situated 6 miles (10 km) east of Ipswich, in Suffolk, England. This was an ancient area of heathland and latterly the site of Martlesham Heath Airfield. A "new village" was established there in the mid-1970s and th ...
for trials in the specification competition. In February 1935 the sole 253 flew with an uprated Pegasus IIIM3. The Type 253 won the competition and an order for 150 aircraft. However, on 19 June 1935, Summers flew the Type 246 monoplane that Vickers had built to the same specification as a private venture, which was to become the prototype Type 287 Wellesley. It was immediately apparent that the monoplane offered better performance and a greater payload, so the Type 253 order was cancelled and replaced with one for the Wellesley in September 1935.


Specifications


References


Notes


Bibliography

* * * * {{Vickers aircraft Type 253 1930s British military aircraft Single-engined tractor aircraft Biplanes Aircraft first flown in 1934