The Wyvern project was initiated by Westland as a naval strike fighter, with the engine situated behind the pilot and driving a propeller in the nose via a long shaft that passed under the cockpit floor, similar to the Bell P-39.
This configuration allowed for optimal visibility over the nose during carrier operations.
The Air Ministry Specification N.11/44 was issued to cover Westland’s design, which called for a long-range naval fighter using the 24-cylinder H-block Rolls-Royce Eagle 22 piston engine.
The specification also required an airframe design that could accommodate a turboprop engine when a suitable unit became available.
A parallel specification for the Royal Air Force, F.13/44, was submitted by Hawker with the competing P.1027, a development of the Tempest.
However, the RAF variant was cancelled in 1945 when it was decided that all future fighter aircraft would be jet-powered.
The original design evolved into the more conventional Westland W.34, with the 3,500 hp (2,610 kW) Eagle engine in the nose driving large contra-rotating propellers and the pilot sitting high in a humped fuselage to improve visibility.
The design was otherwise orthodox, with a low wing, tailwheel undercarriage, and double-folding wings fitted with both Youngman flaps on the inner wing section and conventional flaps on the outer section.
The W.34 was to be armed with four Hispano 20 mm cannon in the wings and have the ability to carry a torpedo under the fuselage or a selection of bombs and rockets under the wings.
The prototype W.34, the Wyvern TF.1, first flew at Boscombe Down on 16 December 1946 with Westland’s test pilot Harald Penrose at the controls.
Unfortunately, this aircraft was lost on 15 October 1947 when the propeller bearings failed in flight, resulting in the death of Westland’s assistant test pilot Sqn Ldr Peter Garner.
From prototype number three onwards, the aircraft were navalised and carried their intended armament.
However, the Eagle engine was cancelled, and it was found that there were insufficient pre-production engines available to complete all the prototype and pre-production aircraft.
Specification N.12/45 was therefore issued for the Wyvern TF.2, to be powered by a turboprop engine: either the Rolls-Royce Clyde or the Armstrong Siddeley Python.
A single Clyde-powered prototype was ordered along with two with Pythons.
A Clyde-powered TF.2 first flew on 18 January 1949, but the flight was cut short to only three minutes when the cockpit filled with smoke from a fuel leak onto the exhaust ducting.
Clyde development was subsequently cancelled by Rolls-Royce after only 50 hours of flight time for the TF.2, and the aircraft was delivered to Napier & Son to be fitted with the Nomad turbo-compound engine.
However, the latter engine never materialised, and this aircraft was used for crash barrier trials.
The first Python-powered TF.2 flew on 22 March 1949 and introduced the ejection seat to the Wyvern.
Twenty TF.2s were completed to the Python design, although after three years of testing, a myriad of detailed aerodynamic changes resulted.
The Python engine responded poorly to minor throttle adjustments, so control was exercised by running the engine at a constant speed and varying the pitch of the propellers.
The aircraft was declared ready for service in 1952 but never reached an operational squadron.
The definitive Wyvern model was the TF.4, later S.4. Initially, 50 S.4s were ordered and were joined by the last 7 TF.2s, which were altered while still under construction.
S.4s reached limited shore-based frontline service in May 1953 with 813 Naval Air Squadron at RNAS Ford, replacing the somewhat similar Blackburn Firebrand.
Several second-line squadrons also received Wyverns around this time.
The Westland Wyvern was a British single-seat carrier-based multi-role strike aircraft that served in the 1950s, seeing active service in the 1956 Suez Crisis.
Production Wyverns were powered by a turboprop engine driving large and distinctive contra-rotating propellers and could carry aerial torpedoes.
4-bladed Rotol contra-rotating, 13 ft (4.0 m) diameter
383 mph (616 km/h, 333 kn) at sea level,
380 mph (612 km/h) at 10,000 ft (3,048 m)
910 mi (1,460 km, 790 nmi)
28,000 ft (8,500 m)
Rate of climb
2,350 ft/min (11.9 m/s)
59.7 lb/sq ft (291 kg/m2)
4 × 20mm British Hispano Mk.V cannon, 2 in each wing
16 × RP-3 under wing rockets
1 × Mk.15 or Mk.17 torpedo
Up to 3,000 lb (1,361 kg) of bombs or mines.
Sources Westland Aircraft Since 1915-Derek N. James. The Book of Westland Aircraft-A H Lukins. Westland, Plane Makers 2-David Mondey. Westland Wyvern-Michal Ovcacik & Karel Susa. A History of the Westland Wyvern-Blackbushe Aviation Research Group. Westland Wyvern, From the Cockpit 1-Michael J. Doust.