When the British Government reversed the controversial decision to abandon development of manned aircraft in 1958 they realized that the hiatus in fighter design meant that there would be a gap between the start of developing the new fighter aircraft for the RAF and Royal Navy and their service delivery. To help plug this gap the British Government signed a deal with France to develop an anglicized version of the Mirage III delta winged supersonic fighter built by Dassault.
To help keep the British aviation industry alive the government demanded that as much British equipment should be fitted as possible. This included the powerplant. The decision was made to fit the Rolls Royce Spey turbofan in place of the French Atar turbojet. This required a major redesign of the central fuselage and the engine fit was always a tight one. The prototype took off on March 13th 1964 but immediately ran into difficulty with the engne struggling for air. This was alleviated by increasing the volume of the jet intakes. The Spey also necessitated the addition of an extended jetpipe at the rear. The Spey reduced performance overall but increased range by a considerable margin. In tight turns at high altitude the aircraft was sluggish by comparison with its French forebear but at lower altitudes where the air was thicker the Spey-Mirages were superior.
Combat SystemsEditMain armament consisted of a slightly improved version of Red Top two of which were the normal loadout giving it the same weaponload as the EE Lightning but the Mirage had greater range. Like the French Mirages, two 20mm cannons were loacted beneath the engine intakes. Early plans for the addition of American AIM-7 Sparrow medium range air to air missiles were always on the "to-do list" and while one aircraft flew with dummy rounds under the wings for aerodynamic evaluation the weapon was never adopted operationally. A Sky Guardian Radar Warning Receiver (RWR) was added to the vertical fin in a distinctive box mounting making the British Mirages more advanced than their French brethren. Finally the British aircraft were equipped with the Blue Light radar which while being quite capable for the day was quite clumsy and work-intensive to operate by the single pilot.
RAF ServiceEditBAC undertook production of an eventual 112 Mirage IIIKs and 20 Mirage IIIKT two seat trainers (known as T.2s in the RAF) at its Warton facility with the first reaching operational squadrons at home and abroad by 1965. The first unit to re-equip with the type was No.111 Squadron based at RAF Leuchars. No.111 Squadron would prove the exception in that it was the only UK based squadron of Mirage FAW.1s the rest all going to squadrons based in Germany. The RAF's tenure with the Mirage was short lived however. Within ten years they were gradually withdrawn as newer and more capable British fighters became available. Most were relegated to the Royal Auxiliary Air Force while about thirty found their way to the Royal Navy.
Never loved by British pilots the Mirage IIIK squadrons were always the first to re-equip. Royal Navy operations ceased in 1977 when the 'Land Lover' force was scrapped in favour of deployments from fleet squadrons. The last operational Mirage FAW.1 mission was flown by No.652 (City of Leeds) Squadron, RAuxAF on October 13th 1987. By that time the relatively few survivors had received the overall grey scheme that was beginning to adorn RAF fighter aircraft.