The de Havilland DH100 Vampire is a British jet fighter developed and manufactured by the de Havilland Aircraft Company. It was the second jet fighter to be operated by the Royal Air Force (RAF), after the Gloster Meteor, and the first to be powered by a single jet engine.
Development of the Vampire as an experimental aircraft began in 1941 during the Second World War, to exploit the revolutionary innovation of jet propulsion. From the company's design studies, de Havilland decided to use a single-engined, twin-boom aircraft, powered by the Halford H.1 turbojet (later produced as the Goblin). Aside from its propulsion system and twin-boom configuration, it was a relatively conventional aircraft. In May 1944, de Havilland decided to produce the aircraft as an interceptor for the RAF. In 1946, the Vampire entered operational service with the RAF, only months after the war had ended.
The Vampire quickly proved to be effective and was adopted as a replacement of wartime piston-engined fighter aircraft. During its early service, it accomplished several aviation firsts and achieved various records, such as being the first jet aircraft to cross the Atlantic Ocean. The Vampire remained in front-line RAF service until 1953, when its transfer began to secondary roles such as ground attack and pilot training, for which specialist variants were produced. The RAF retired the Vampire in 1966, when its final role of advanced trainer was filled by the Folland Gnat. The Royal Navy had also adapted the type as the Sea Vampire, a navy-adapted variant suitable for operations from aircraft carriers. It was the service's first jet fighter.
The Vampire was exported to many nations and was operated worldwide in numerous theatres and climates. Several countries used the type in combat including the Suez Crisis, the Malayan Emergency, and the Rhodesian Bush War. By the end of production, almost 3,300 Vampires had been manufactured, a quarter of these having been manufactured under licence abroad. De Havilland pursued the further development of the type; major derivatives produced include the DH.115, a specialised, dual-seat trainer and the more advanced DH.112 Venom, a refined variant for ground-attack and night-fighter operations.
Development Origins In January 1941, Sir Henry Tizard made an informal approach to the de Havilland Aircraft Company, suggesting that the company proceed to design a fighter aircraft that would use the revolutionary new jet propulsion technology then under development, along with an appropriate engine to go with it. Although no official specification had been issued, de Havilland proceeded to design a single-engined aircraft that had air intakes set into the wing roots to feed a centrally mounted engine, which used a centrifugal compressor.
Aero-engine designer Major Frank Halford had been given access to Frank Whittle's pioneering work on gas turbines; for the projected jet-powered fighter, Halford decided to proceed with the design of a "straight through" centrifugal engine capable of generating 3,000 lb of thrust, which was considered to be high at the time. Halford's engine emerged as the Halford H.1. By April 1941, design work on the engine had been completed and a prototype H.1 engine performed its first test run one year later.
The low power output of the early jet engines had meant that only twin-engined aircraft designs were considered to be practical, and as more powerful jet engines were quickly developed, particularly Halford's H.1 (later known as the de Havilland Goblin), the practicalities of the single-engined jet fighter were soon realised. de Havilland was approached to produce an airframe for the H.1 as insurance against Germany using jet bombers against Britain; this was considered more important than de Havilland's suggestion of a high-speed jet bomber."De Havilland DH100 Vampire." BAE Systems, Retrieved: 18 May 2017. Its first design, the DH.99, was set out in a brochure dated 6 June 1941; it was an all-metal, twin-boom, tricycle undercarriage aircraft armed with four cannon. The use of a twin boom enabled the jet pipe to be kept relatively short, which avoided the power loss that would have occurred if a long pipe were used, as would have been necessary in a conventional fuselage. It also put the tailplane clear of interference from the exhaust. Performance was estimated at at sea level and initial climb of on 2,700 lb of thrust. The Ministry of Aircraft Production (MAP) representative expressed doubts regarding the lack of detail, estimations for the aircraft's performance and optimistic structure weight; the project received permission to proceed in July 1941.
The DH.99 design was soon modified to incorporate a combined wood-and-metal construction in light of recommendations from the MAP; the design was thus renumbered to DH.100 by November 1941. The aircraft was considered to be a largely experimental design due to its use of a single engine and some unorthodox features, unlike the Gloster Meteor, which had been specified for production early on. In February 1942, the MAP suggested dropping the project for a bomber, but de Havilland stated that the twin-boom was, despite ministry doubts, only an engineering problem to be overcome. On 22 April 1942, the construction of two prototypes (serials LZ548 and LZ551) was authorised by the ministry, whilst Specification E.6/41 was produced and issued to cover the work. The company proceeded with the detailed design work phase of the DH.100 in early 1942.
Internally designated as the DH.100 and originally codenamed Spider Crab,Winchester 2012, p. 30. the aircraft was entirely a de Havilland project, being principally worked upon at the company's facility at Hatfield, Hertfordshire. The construction of the aircraft exploited de Havilland's extensive experience in the use of moulded plywood for aircraft construction, which had previously been used on the Mosquito, a widely produced fast bomber of the war.
The layout of the DH.100 used a single jet engine installed in an egg-shaped fuselage that was primarily composed of plywood for the forward section and aluminium throughout the aft section. It was furnished with conventional, mid-mounted, straight wings; air brakes were installed on the wings to slow the aircraft, a feature that had also been incorporated in the Meteor. Armament comprised four 20 mm Hispano Mk V cannon underneath the nose; from the onset of the design phase, even when the aircraft was officially intended to serve only as an experimental aircraft, the provision for the cannon armament had been included.
On 20 September 1943, the first DH.100 prototype, serial number LZ548/G, conducted its maiden flight from Hatfield Aerodrome; it was piloted by Geoffrey de Havilland Jr., the company's chief test pilot and son of the company's founder. This flight took place only six months after the Meteor had performed its own maiden flight; the first flight had been delayed due to the need to dispatch the only available engine suitable for flight to America to replace one destroyed in ground engine runs in Lockheed's prototype XP-80 jet fighter. Three prototypes, LZ548/G, LZ551/G, and MP838/G, were produced to support the type's development. Testing showed the main problem was with directional instability – the aircraft "snaking" – this was corrected by changes to the tail design.
Production and further development On 13 May 1944, an initial production order for 120 Vampire Mk I aircraft was received and quickly increased to 300 aircraft. The production Vampire Mk I did not fly until April 1945. Owing to the wartime pressures upon de Havilland's production facilities for existing aircraft types, English Electric Aircraft undertook production of the Vampire at their factories at Preston in Lancashire, instead; the company went on to produce the majority of the aircraft. Only about half a dozen production aircraft had been built by the end of the Second World War, although it did not result in the type becoming a victim of the extensive postwar cuts that were soon implemented, which had terminated the production of many aircraft along with development work upon several more. Eventually, however, 244 production Mk 1 Vampire aircraft were built.
De Havilland initiated a private venture night fighter, the DH.113, intended for export, fitting a two-seat cockpit closely based on that of the Mosquito night fighter and a lengthened nose that accommodated an AI Mk X radar. An order to supply the Egyptian Air Force was received, but this was blocked by the British government as part of an embargo on supplying arms to Egypt. The RAF took over the order and put them into service as an interim measure between the retirement of the de Havilland Mosquito night fighter and the full introduction of the Meteor night fighter. Removal of the radar from the night fighter and fitting of dual controls resulted in a jet trainer model of the aircraft, the DH.115 Vampire, which entered British service as the Vampire T.11. This trainer variant was built in large numbers for the RAF and for export.
An alternative powerplant to the de Havilland Goblin soon became available in the form of the Rolls-Royce Nene, another turbojet engine capable of generating similar levels of thrust. The name Vampire II was given to three experimental Nene-powered Vampires, which were used to assess their performance. One of these was evaluated by the RAF before the rival Goblin was selected for the RAF Vampires, instead; another contributed to development work for the Vampires for the Royal Australian Air Force (RAAF).
Although the Nene had a higher thrust than the Goblin, its level flight speed was no greater. To reduce the intake losses caused by having to feed air to the rear face of the impeller of the Nene, two additional intakes were added behind the cockpit; these caused elevator reversal and buffeting, which in turn reduced the Vampire's Mach limit.Harvey, Heyworth & Jackson 2006, p. 109. The Vampires of the RAAF were powered by the Nene engine; these were initially outfitted with dorsal intakes, later moved underneath the fuselage. In 1949, Boulton Paul Aircraft redesigned the wing-root intakes and internal ducting based on the installation of the Nene in the prototype Hawker Sea Hawk. The Mistral, the French name for their models of the Vampire, also used the Nene engine with Boulton Paul intakes.
The Vampire III was the first of several models that sought to address the demands for greater range from the type. Underwing fuel drop tanks of 100- and 200-gallon capacities were fitted; other modifications included lowering the tailplane and reshaping the vertical surfaces of the tail. The design changes to accommodate the hardpoint-mounted drop tanks had the benefit of enabling the carriage of various stores and readied the type for ground-attack operations. The wing was considerably modified to improve low-altitude performance, the span was reduced by 2 ft with the adoption of square-cut wing tips, and the wing skins were thickened and the undercarriage modified to withstand the increased weight. In total, 3,268 Vampires were built in 15 versions, including two-seat night fighters, 804 trainers Air international June 1994 page 346, and carrier-based Sea Vampires. The Vampire was used by 31 air forces. Germany, the Netherlands, Spain, and the U.S. were the only major Western powers not to use the aircraft.
Records and achievements