The de Havilland DH.110 Sea Vixen was originally ordered as a two-seat, twin-boom radar-equipped fighter to specification F.4/48 and was in direct competition with the Gloster Javelin. Although losing in that competition, the Royal Navy felt that the de Havilland DH.110 was better for its requirements for a carrier-based fleet defence strike fighter. This led to the release of a new specification, N.131T, written specifically with the DH.110 in mind. De Havilland Aircraft Company had opted for the twin-boom configuration, seen in its Vampire and Venom aircraft, with an all-metal fuselage featuring swept and, eventually, foldable wings.
Fitted with Rolls-Royce Avon 208 turbojets, the prototype (WG326) flew for the first time at Hatfield on 26th September 1951, piloted by John ‘Cats Eyes’ Cunningham. Early test flights exceeded expectations in both speed and performance, with the aircraft flying well in excess of the speed of sound. However, despite this initial success, less than a year later the project would suffer a great tragedy.
At the Farnborough Air Show in 1952, the prototype Sea Vixen, while being displayed to the crowd with the intention of creating a sonic boom, suffered a sudden structural break-up during a high G turn. The break-up saw the engines continued forward into the crowd, killing 29 spectators and injuring many others, while both the Test Pilot John Derry and Flight Engineer Tony Richards also lost their lives in the incident.
After this tragedy, the remaining de Havilland DH.110 prototype (WG240) underwent a period of redesign, and it was almost a year before it recommenced flight trials. After successful carrier trials, the Fleet Air Arm decided to replace its Sea Venoms with the Sea Vixen, and placed an order for 110 ‘Navalised aircraft’ which was subsequently renamed the De Havilland DH.110 Sea Vixen FAW.
In June 1955, a semi-navalised De Havilland DH.110 Sea Vixen FAW Mk20X prototype (XF828) completed carrier flight deck suitability trials, which included catapult launches and arrester hook landings, although the powered folding wings capability was not incorporated until April 1956. The first production aircraft flew on 20th March 1957, with the construction of the vast majority of the aircraft being completed at Christchurch, near Bournemouth, although after 1962, with the advent of the consolidation of the aircraft industry, all De Havilland DH110 Sea Vixen work was transferred to Harwarden, near Chester.
During its operational career the DH.110 Sea Vixen provided cover duties based from various carriers around the world, and while never seeing active combat duty, Sea Vixens did on one occasion release bombs and rockets operationally. This occurred on the 28th March 1967, when they were used on the wreck of the oil tanker Torrey Canyon, a 120,000 ton oil tanker which ran aground on Seven Stones Reef off the tip of Cornwall ten days earlier, in an effort to ignite the resultant oil slick and aid in its dispersion.
In total, a single prototype and 119 De Havilland DH.110 Sea Vixen FAW.1’s were built, followed by 29 De Havilland DH.110 Sea Vixen FAW.2, to which configuration many (67) of the surviving FAW.1 aircraft were converted.