Editing Dassault Mirage III (section)

===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]].<ref name = "WAPJ14 p120">Jackson ''World Air Power Journal'' Volume 14, p. 120.</ref><ref name = "prof 173"/> 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''.<ref name = "prof 173 175">Brindley 1971, pp. 173, 175.</ref> 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.<ref name="Mirage III"/> 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.<ref name = "prof 175">Brindley 1971, p. 175.</ref> 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.<ref name="Mirage III"/>

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.<ref name = "prof 175"/> 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 {{convert|43.2|kN|lbf|abbr=on}} of thrust. The Atar was an axial-flow turbojet design, having been derived from the [[Germany|German]] [[World War II|Second World War]]-era [[BMW 003]] engine.<ref>Smith 1955, p. 266.</ref> The new Atar-equipped fighter design received the name ''Mirage III''.<ref name = "prof 175"/> There was also an even larger ''heavy fighter'' design drafted, referred to as the [[Dassault Mirage IV|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.<ref name = "prof 175"/>

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.<ref name = "prof 175"/> 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.<ref name="WAPJ14 p120" /><ref name = "prof 175"/> During its 10th flight, it was recorded as having attained a speed of Mach 1.52 at one point.<ref name="mca p12">Jackson 1985, p. 12.</ref> During the course of the flight test programme, the prototype was fitted with a pair of manually-operated intake half-cone [[Diffuser (thermodynamics)#Supersonic Diffusers|shock diffusers]], known as ''souris'' ("mice"), 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 (as fitted to the Mirage I) had allowed for a speed of Mach 1.8 to be reached in September 1957.<ref name="WAPJ14 p120"/><ref name = "mca p12" /><ref name = "prof 175"/>

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.<ref name = "prof 175"/> 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 {{convert|58.9|kN|lbf|abbr=on}}. The [[SEPR 841]] rocket engine was also retained.<ref name=seprunion4>{{cite journal|journal=S.E.P.R. Union Revue d'Information du Personnel |date=February 1959 |issue=4 |page=34 |url=http://dev.museesafran.com/wp-content/uploads/2012/10/1350048123-revues-sep-union-saf2012_0047323.pdf |title=no title |access-date=26 October 2014 |language=fr }}{{dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The Mirage IIIA was also fitted with a [[Thomson-CSF]]-built [[Cyrano (radar)|Cyrano Ibis]] [[Fire-control radar|air intercept radar]], operational-standard avionics, and a [[Drogue parachute|drag chute]] to shorten its landing roll.

In May 1958, the first Mirage IIIA conducted its first flight.<ref name = "prof 175"/> On 24 October of that year,<ref name=":0" /> 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.<ref name = "prof 175"/> The test regime involved a wide variety of tasks, including the evaluation of the newer SEPR 841 rocket motor, various underwing [[drop tank]]s, and other major systems.<ref name = "prof 175 176">Brindley 1971, pp. 175–176.</ref> One Mirage IIIA was powered by a [[Rolls-Royce Avon|Rolls-Royce Avon 67]] engine capable of generating {{convert|71.1|kN|lbf|abbr=on}} of thrust, to serve as a test model for [[Australia]]n 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.<ref name="gunston 86">Gunston 1976, p. 86.</ref><ref>Brindley 1971, pp. 176, 182.</ref>