The Gloster Javelin was a tailed delta winged all-weather fighter that served in the Royal Air Force from 1956 to 1968. It emerged as a result of Operational Requirement OR.227 which outlined the performance the aircraft was to have. It was to be capable of achieving 525 knots in level flight at an altitude of 40,000ft and would feature a radar set from the outset (most nightfighters to that point had radar fitted later such as the Gloster Meteor). Armament comprised of the standard quadruple 30mm cannons which was how nearly all fighters in the RAF were equipped towards the end of the war as this was seen as being the best balance between hitting power and weight considerations. More revolutionary however was the equipping of four air-to-air missiles.
Gloster produced a delta winged design which was becoming quite fashionable in the West in the late 1940s thanks in no small part to captured German technology. Very quickly Gloster realized that their new aircraft was going to be a heavy design and this saw the engines changed from Rolls-Royce Avons to Rolls-Royce Sapphires. The prototype aircraft called the GA.5 first flew on November 26th 1951 but testing proved extremely troublesome with severe vibration troubles as a result of the hight T-tail. This would be an ongoing problem the engineers at Gloster would have to address but not before the death of one of the test pilots. Gloster pressed on however and when the RAF settled on the design the aircraft entered service in 1956. Nevertheless the aircraft was continually developed throughout its life as experience grew.
Apart from the trainer variant all fighter versions of the Javelin had the designation FAW (Fighter All Weather).
The original production version was powered by Sapphire Sa.6 engines rated at 8,000 lbf (35.6 kN thrust) each. Radar came in the form of the British AI.17 that could be used to train the four 30 mm ADEN cannons in the wings. The tailplane was electrically-operated but this proved unsatisfactory. 40 were produced to this standard but because many of the aircraft’s handling problems had not yet been ironed out they were flown under a plethora of restrictions.
The FAW.2 saw the replacement of the British AI.17 radar with the more capable AI-22 (the British version of the American APQ-43 system). The fitting of the new radar required the nosecone to be enlarged giving the new version a tubbier look at the front. Power to the tail was now hydraulic and a total of 30 were manufactured.
With there being no real training aircraft capable of simulating the new sophisticated aircraft a dual-control trainer version was produced. This dispensed with the radar and included a bulged canopy for improved instructor visibility. The loss of the radar seriously upset the balance of the aircraft necessitating a lengthened fuselage and all moving tailplane to compensate. The aircraft retained the four cannons as its primary armament but had to be trained in the traditional method with there being no radar. The T.3 served with No.228 Operational Conversion Unit at RAF Leeming.
The FAW.4 was essentially a FAW.1 with the original AI.17 radar set but featured vortex generators on the wings for improved stall characteristics; something that had plagued the aircraft since the prototype as a result of the high T-tail. Additionally the all-moving tailplane of the T.3 was fitted for improved control at higher speeds. It was one of the first widely distributed variants serving in a total of six squadrons.
The FAW.5 was a FAW.4 but with a revised wing design that allowed it carry more fuel thuis extending range for interception missions over the North Sea if necessary. More importantly however it was the first version to finally have provision for four missile pylons. Although a step closer to meeting the requirement in which the aircraft was born the pylons were never fitted operationally.
33 FAW.2s with the American AI.22 radar were reworked to feature the new wing of the FAW.5 and this produced the FAW,6. Again the aircraft now had the provision for four air-to-air missiles but these were never fitted in service.
The FAW.7 was the mark where the aircraft finally matured into the aircraft it was meant to be. Introducing new Rolls-Royce Sapphire Sa.7 engines with 11,000 lbf (48.9 kN) thrust each, a powered rudder and extended rear fuselage the aircraft dispensed with two of the four 30mm ADEN guns that had been in previous marks but finally added four Firestreak air-to-air missiles. A FAW.7 conducted the type’s first missile firing in June 1960. A large number of FAW.7s were ordered but the early introduction of the FAW.8 version meant a large number were delivered directly in to storage.
Now that the Javelin finally had its long overdue missile armament the next step was to fit the Sapphire Sa.7 engines with reheat raising thrust to 12,300 lbf (54.7 kN). This made it a more capable interceptor at high altitude but at take off the fuel pump couldn’t deliver fuel fast enough to power the afterburner and resulted in an actual loss of power. Therefore the pilot was restricted to only using reheat at 20,000ft and above. Aerodynamically the aircraft featured a new “drooped” wing leading edge and auto-stabilizer that went a long way to improving handling.
The FAW.9 was the definitive version of the aircraft and a total of 118 FAW.7s were converted to this status by fitting the revised wing and engines of the FAW.8. First flying in 1959 the Javelin was already beginning to show its age compared to the new supersonic designs being developed in the US and the USSR. It was still a potent bomber destroyer however but retained the Firestreak missile which was being replaced by the more capable Red Top air-to-air missile on the Lightning and Royal Navy’s Sea Vixen.
44 FAW.9s were modified to undertake the relatively new practice of air-to-air refuelling by the fitting of a large refuelling probe which perhaps appropriately looked more like a Javelin than the aircraft itself. Later the aircraft were modified again to carry underwing drop tanks extending operational range further.