Vickers Type 253 K2771 '6' taxying at the RAF Pageant at Hendon.
The Vickers Aviation Type 253 was a single engine, two seat biplane was designed by Barnes Wallis and Rex Pierson, to meet the requirements of Specification G.4/31 which called for a general-purpose bombing and torpedo aircraft to replace the Westland Wapati.
It was developed in parallel with a private-venture monoplane prototype, which later entered production as the Vickers Wellesley, described separately on its own web page.
The Type 423 was powered by a Bristol Pegasus engine and used a geodetic structure for the rear fuselage, drawing on the experience that Barnes Wallis had gained in the construction of airships – notably the Vickers-built R-100.
The Vickers Type 253 was Barnes Wallis' first aircraft to use a geodetic fuselage structure.
A geodesic is the shortest line between two points on a curved surface and Wallis identified this structural approach as providing efficient load distribution in a structure whilst also introducing redundant load paths to create a fail-safe and damage tolerant structure. The aim was to achieve a lattice-like structure that required no underlying secondary structure to give it strength.
In the Vickers Type 253, this system was partially introduced in the fuselage structure on the private-venture Vickers G.4/31 monoplane, developed by Vickers in parallel, adopting a full geodetic structure for both wings and fuselage.
Vickers Type 253 K2771 photographed at Brooklands carrying a dummy torpedo.
The Vickers Type 253 (K2771) made its first flight at Brooklands on 16th August 1934, with Matt Summers at the controls, and powered by a 635 ho Bristol Pegasus IIM3 engine. In early 1935, this engine was replaced with a Bristol Pegasus IIIM3.
The Vickers Type 423 was the subject of comparative trials with the G.4/31 monoplane prototype at the Aeroplane and Armament Experimental Establishment (A&AEE), Martlesham Heath and unfortunately, the G.4/31 demonstrated the clear advantage of the monoplane. With its fully-geodetic structure, the monoplane had a lighter empty weight and had superior performance at higher weights than the Type 423 thereby delivering better payload and range characteristics.
As a result, further development of the Vickers Type 253 was abandoned, although the sole example (K2771) continued to give valuable service to the Bristol Engine Company as a flying test-bed.
Ultimately, the airframe was donated to 385 Sqn (Coulsdon & Purley) of the Air Training Corps where its ultimate fate is unknown.
Variants & Numbers
One aircraft only (K2771)
Specification
| Powerplant | One 635 hp Bristol Pegasus IIM3 engine |
| Span | 52 ft 7 in |
| Maximum Weight | 8,350 lb |
| Capacity and armament | Pilot and observer; provision for the carriage of up to 8 bombs under the wings and a torpedo between the undercarriage legs. Armament two Lewis machine guns – one forward firing and one fired from the observer position. |
| Maximum Speed | 161 mph at 4,500 ft |
