Dassault Mirage III
The Dassault Mirage III is a family of single/dual-seat, single-engine, fighter aircraft developed and manufactured by French aircraft company Dassault Aviation. It was the first Western European combat aircraft to exceed Mach 2 in horizontal flight, which it achieved on 24 October 1958.
In 1952, the French government issued its specification, calling for a lightweight, all-weather interceptor. Amongst the respondents were Dassault with their design, initially known as the Mirage I. Following favourable flight testing held over the course of 1954, in which speeds of up to Mach 1.6 were attained, it was decided that a larger follow-on aircraft would be required to bear the necessary equipment and payloads. An enlarged Mirage II proposal was considered, as well as MD 610 Cavalier, but was discarded in favour of a further-developed design, powered by the newly developed Snecma Atar afterburning turbojet engine, designated as the Mirage III. In October 1960, the first major production model, designated as the Mirage IIIC, performed its maiden flight. Initial operational deliveries of this model commenced in July 1961; a total of 95 Mirage IIICs were obtained by the French Air Force. The Mirage IIIC was rapidly followed by numerous other variants.
The Mirage III was produced in large numbers for both the French Air Force and a wide number of export customers. Prominent overseas operators of the fighter included Argentina, Australia, South Africa, Pakistan and Israel, as well as a number of non-aligned nations. Often considered to be a second-generation fighter aircraft, the Mirage III experienced a lengthy service life with several of these operators; for some time, the type remained a fairly maneuverable aircraft and an effective opponent when engaged in close-range dogfighting. During its service with the French Air Force, the Mirage III was normally armed with assorted air-to-ground ordnance or R.550 Magic air-to-air missiles. Its design proved to be relatively versatile, allowing the fighter model to be readily adapted to serve in a variety of roles, including trainer, reconnaissance and ground-attack versions, along with several more extensive derivatives of the aircraft, including the Dassault Mirage 5, Dassault Mirage IIIV and Atlas Cheetah. Some operators have undertaken extensive modification and upgrade programmes, such as Project ROSE of the Pakistan Air Force.
The Mirage III has been used in active combat roles in multiple conflicts by a number of operators. The Israeli Air Force was perhaps the most prolific operator of the fighter outside of France itself; Israel deployed their Mirage IIIs in both the Six-Day War, where it was used as both an air superiority and strike aircraft, and the Yom Kippur War, during which it was used exclusively in air-to-air combat in conjunction with the IAI Nesher, an Israeli-built derivative of the Mirage 5. Ace of aces Giora Epstein achieved all of his kills flying either the Mirage III or the Nesher. During the South African Border War, the Mirage III formed the bulk of the South African Air Force's fleet, comprising a cluster of Mirage IIICZ interceptors, Mirage IIIEZ fighter-bombers and Mirage IIIRZ reconnaissance fighters; following the introduction of the newer Mirage F1, the type was dedicated to secondary roles in the conflict, such as daytime interception, base security, reconnaissance and training. The Argentine Air Force used the Mirage IIIEA during the Falklands War, but their lack of an aerial refueling capability limited the aircraft's usefulness in the conflict. Even using drop tanks, the Mirages only had an endurance of five minutes within the combat area around the British fleet.
Development
Origins
The Mirage III family has its origins within a series of studies conducted by the French Defence Ministry which had commenced in 1952. At the time, several nations had taken an interest in the prospects of a light fighter, which had been motivated by combat experiences acquired during the Korean War, specifically the Soviet-built Mikoyan-Gurevich MiG-15 jet-propelled fighter aircraft which had drawn considerable attention internationally. Western nations were keen to explore the performance of a relatively uncomplicated and heavily armed jet-powered swept wing fighter, inspired by the rapid advances in aircraft capabilities that had been made by the Soviet Union. France was one of the quickest governments of several nations, including the United Kingdom, the United States, and Italy, to embark on encouraging the development of such an aircraft.In 1952, the French government issued its specification, calling for a lightweight, all-weather interceptor, capable of climbing to in 6 minutes along with the ability to reach Mach 1.3 in level flight. Three separate French manufacturers decided to respond to the specification, these being Dassault Aviation, Sud-Est, and Sud-Ouest, offering the MD.550 Mystère Delta, SE.212 Durandal and SO.9000 Trident, respectively. Dassault's submission, which became known as the MD.550 Mystère Delta, was a diminutive and sleek-appearing aircraft that was principally powered by a pair of Armstrong Siddeley MD30R Viper afterburning turbojet engines ; atypically, the design also featured provisions for the installation of a secondary propulsion system in the form of a SEPR-built 66 liquid-fuel rocket engine, capable of providing boost thrust of.
The basic layout of the MD.550 Mystère Delta featured a tailless delta configuration, possessing a 5 per cent thickness and 60° sweep, complete with a large vertical stabilizer and rudder. However, the tailless delta configuration imposed a number of limitations, including the lack of a horizontal stabilizer, which meant that conventional flaps could not be used; this resulted in a relatively long takeoff run and a high landing speed. The delta wing itself limits maneuverability and suffers from buffeting at low altitude due to the large wing area and resulting low wing loading. However, the delta is a simple design, easy to construct and relatively robust while providing generous amounts of internal volume in the wing for fuel and being capable of achieving high speeds when flown in a straight line.
British aviation author Derek Wood observed that there was "a striking resemblance" between the MD.550 Delta and the British Fairey Delta 2, an experimental aircraft that first flew on 6 October 1954, and which set a new world speed record on 1 March 1956. During the latter stages of testing of the Fairy Delta 2 in October and November 1956, the FD2 performed 47 low level supersonic test flights from Cazaux Air Base, Bordeaux, in France. Dassault engineers observed these trials and obtained additional data on the performance and flight characteristics of delta wing aircraft. The Delta 2 confirmed Dassault's theories, and provided additional supporting evidence for the viability of the Mirage III development.
Flight testing
On 25 June 1955, the first prototype of the MD.550 Mystère Delta, without afterburning engines or rocket motor and with an unusually large vertical stabilizer, conducted its maiden flight. In this configuration, it was able to attain a maximum speed of Mach 1.15. Following initial flights, it received a redesign that involved the vertical stabilizer being reduced in size along with the installation of afterburners and a rocket motor; it was at this point that the aircraft was renamed as the Mirage I. In late 1954, the prototype attained a recorded speed of Mach 1.3 in level flight without rocket assistance, as well as reaching Mach 1.6 when using the rocket motor. According to aviation author John F. Brindley, testing of the Mirage I and prototypes of the rival Trident and Durandal designs had demonstrated the limitations of the light fighter concept, namely limitations on both endurance and equipment/payload capacity. The small size of the Mirage I restricted its armament to a single air-to-air missile, and it was decided during flight trials that the aircraft was too small for the carriage of a useful armament. Following the completion of flying trials, the Mirage I prototype was eventually scrapped.Dassault was keen to produce a successor to the Mirage I prototype; at one point, the firm was considering the production of an enlarged version, known as the Mirage II, which would have been furnished with a pair of Turbomeca Gabizo turbojet engines. However, the Mirage II ultimately remained unbuilt as it was bypassed for an even more ambitious design, being 30 per cent heavier than the original Mirage I, powered by the newly developed Snecma Atar afterburning turbojet engine, capable of generating up to of thrust. The Atar was an axial-flow turbojet design, having been derived from the German Second World War-era BMW 003 engine. The new Atar-equipped fighter design received the name Mirage III. There was also an even larger heavy fighter design drafted, referred to as the Mirage IV. A decisive factor had been interest from the French military, who had made its favour for the Mirage III proposal known to the company.
The Mirage III incorporated various new design principles, such as the transonic area rule concept, where changes to an aircraft's cross-section were made as gradual as possible, resulting in the famous "wasp waist" configuration of many supersonic fighters. Similar to its Mirage I predecessor, the Mirage III had provision for a booster rocket engine. On 17 November 1956, the prototype Mirage III perform its first flight. During its 10th flight, it was recorded as having attained a speed of Mach 1.52 at one point. During the course of the flight test programme, the prototype was fitted with a pair of manually operated intake half-cone shock diffusers, known as souris, which could be moved forward as the Mach number increased. This achieved a reduction in inlet pressure losses by ensuring the fuselage oblique shock remained outside the intake lip. Reportedly, their addition enabled an increased speed of Mach 1.65 to be reached, while use of the supplemental SEPR 66 rocket had allowed for a speed of Mach 1.8 to be reached in September 1957.
The success of the Mirage III prototype resulted in an order for 10 pre-production Mirage IIIA fighters. Although the type had initially conceived of as an interceptor, the batch had been ordered with the intention of using them to develop the type for additional roles as well. The Mirage IIIA were almost 2 meters longer than the Mirage III prototype, had an enlarged wing of 17.3 per cent greater area, a chord reduced to 4.5 per cent, and an Atar 09B turbojet capable of generating afterburning thrust of up to. The SEPR 841 rocket engine was also retained. The Mirage IIIA was also fitted with a Thomson-CSF-built Cyrano Ibis air intercept radar, operational-standard avionics, and a drag chute to shorten its landing roll.
In May 1958, the first Mirage IIIA conducted its first flight. On 24 October of that year, this aircraft achieved a top speed of Mach 2.2 during one of its test flights, thus becoming the first Western European aircraft to exceed Mach 2 in level flight. In December 1959, the tenth and final Mirage IIIA was rolled out; the last six pre-production aircraft were largely representative of the subsequent initial production standard. The test regime involved a wide variety of tasks, including the evaluation of the newer SEPR 841 rocket motor, various underwing drop tanks, and other major systems. One Mirage IIIA was powered by a Rolls-Royce Avon 67 engine capable of generating of thrust, to serve as a test model for Australian evaluation, which was given the Mirage IIIO designation. This variant flew in February 1961, but the Avon powerplant was ultimately not adopted on production aircraft.