Dassault Mirage IV The Dassault Mirage IV was a French jet - propelled supersonic strategic bomber and deep - reconnaissance aircraft . Developed by Dassault Aviation , the aircraft entered service with the French Air Force in October 1964 . For many years it was a vital part of the nuclear triad of the " Force de Frappe " , France ' s nuclear deterrent striking force . The Mirage IV was retired from the nuclear strike role in 1996 , and the type was entirely retired from operational service in 2005 . During the 1960s , there were plans of export sales for the Mirage IV ; in one proposal , Dassault would have entered a partnership with the British Aircraft Corporation to jointly produce a Mirage IV variant for the Royal Air Force and potentially for other export customers , however this project did not come to fruition . The Mirage IV was ultimately not adopted by any other operators beyond the French Air Force . Development . Origins . Work on a supersonic bomber able to carry a nuclear bomb started in France in 1956 as part of the development of France ' s independent nuclear deterrent . In May 1956 , the Guy Mollet government drew up a specification for an aerially refuelable supersonic bomber capable of carrying a 3 - metric - ton , 5 . 2 - meter - long nuclear bomb 2 , 000 km ( without aerial refuelling ) . The final specifications , jointly defined by government authorities and Dassault staff , were approved on 20 March 1957 . Sud Aviation and Nord Aviation both submitted competing proposals , both based on existing aircraft ; Sud Aviation proposed the Super Vautour , a stretched Sud Aviation Vautour with 10 , 500 lb thrust Atar engines and a combat radius of 1 , 700 miles at Mach 0 . 9 . Dassault ' s proposal for what became the Mirage IV was chosen on the basis of lower cost and anticipated simpler development , being based upon a proposed early 1956 twin - engined night - fighter derived from the Dassault Mirage III fighter . Dassault ' s resulting prototype , dubbed Mirage IV 01 , looked a lot like the Mirage III A , even though it had double the wing surface , two engines instead of one , and twice the unladen weight . The Mirage IV also carried three times more internal fuel than the Mirage III . The aircraft ' s aerodynamic features were very similar to the III ' s but required an entirely new structure and layout . This prototype was 67 feet long , had a 37 ft wingspan , 670 square feet of wing area , and weighed approximately 55 , 000 lb . It was considerably more advanced than the Dassault Mirage III , incorporating new features such as machined and chem - milled planks , tapered sheets , a small amount of titanium , and integral fuel tanks in many locations including the leading portion of the tailfin . The 01 was an experimental prototype built to explore and solve the problems stemming from prolonged supersonic flight . The sizable technological and operational uncertainties ( no plane had yet been found able to cruise at over Mach 1 . 8 for long periods of time ) were only one part of the problem . The weapon - related issues were the other . It took 18 months to build the 01 in Dassault ' s Saint - Cloud plant near Paris . In late 1958 , the aircraft was transferred to the Melun - Villaroche flight testing area for finishing touches and ground tests . French General Roland Glavany , on a five - year leave from the French Air Force since 1954 , took the 01 into the air for its maiden flight on 17 June 1959 . For its third flight , on 20 June 1959 , the 01 was authorized to fly over the Paris Air Show at Le Bourget airport in front of France ' s President Charles de Gaulle . On 19 September 1960 , René Bigand ( replacing Glavany as test pilot ) increased the world record for speed on a 1000 - kilometre closed circuit to 1 , 822 km / h ( 1 , 132 mph ) around Paris and the Melun air force base . Flight 138 , on 23 September , corroborated the initial performance and pushed the record on a 500 km closed circuit to an average of 1 , 972 km / h ( 1 , 225 mph ) , flying between Mach 2 . 08 and Mach 2 . 14 . The Mirage IV 01 prototype underwent minor modifications during testing in the autumn of 1959 , most noticeably , the tail was enlarged ( slight reduction in height , large increase in chord ) . Further development . In order to increase range , studies were made of a significantly larger Mirage IVB design , powered by two SNECMA license - built Pratt & Whitney J75 engines and having a wing area of 120 m² ( 1 , 290 sq ft ) compared to 70 m² ( 750 sq ft ) of the prototype IV . This aircraft was to have a speed of Mach 2 . 4 and weigh 140 , 000 lb gross , but was cancelled in July 1959 due to cost . With the Mirage IVB considered to be too expensive , the medium - sized Mirage IVA , slightly larger than the first prototype , was chosen for three more prototypes to be produced . This aircraft had a wing area of 839 square feet and weighed about 70 , 000 lb These three aircraft were built between 1961 and 1963 , with first flights on October 12 , 1961 ; June 1 , 1962 ; and January 23 , 1963 . The second prototype conducted simulated nuclear bombing runs in the trials range at Colomb - Bechar in southern Algeria . The third prototype tested the navigation system and flight refuelling probe . The fourth prototype Mirage IVA - 04 was essentially representative of the production aircraft . For production , some parts of the aircraft were subcontracted to Sud Aviation ( wings and rear fuselage ) and Breguet Aviation ( tailfin ) , still a separate company from Dassault until 1967 ; Dassault manufactured the front fuselage and flight - control system . The first production Mirage IVA was flown in December 7 , 1963 . A series of 62 aircraft were built , and they entered service between 1964 and 1968 . Although Dassault had designed the Mirage IV for the low - level flight role right from the start , the final 12 ordered in 1964 differed from the earlier aircraft in details of the flight controls , avionics , and structural details to improve low - level performance . These changes were later retroactively applied to the whole fleet . The Mirage IV force soon consisted of nine squadrons of four aircraft ( 2 pairs — one aircraft carrying the nuclear bomb , one a buddy - refuelling tanker ) each , three squadrons each at the airbases at Mont de Marsan , Istres , and St . Dizier . By 1963 , most Mirage IV missions were planned as low - level flights . In December 1963 , Dassault proposed a Mirage IV - 106 variant with 2 SNECMA TF106 ( license - built Pratt and Whitney ) engines , an enlarged 105 , 000 gross - weight fuselage , terrain - avoidance radar , and armed with a proposed French version of the American Douglas GAM - 87 Skybolt air - launched ballistic missile . This version would have been very costly , and ultimately was not ordered . Proposed export variants . In 1963 , the Australian government sought a replacement for the Royal Australian Air Force fleet of English Electric Canberra bombers , largely in response to the Indonesian Air Force ' s purchase of missile - armed Tupolev Tu - 16 bombers . Dassault proposed a version of the Mirage IVA with Rolls - Royce Avon engines . Australian Air Marshall Frederick Scherger seriously considered purchase of the IVA in 1961 because it was considered proven hardware already in service ( in contrast to the BAC TSR - 2 still in development ) , before settling on the General Dynamics F - 111C . The IVA was one of five aircraft types short listed but the General Dynamics F - 111C was eventually selected . In April 1965 , the British Government cancelled the BAC TSR - 2 reconnaissance - strike aircraft . In response , Dassault and British Aircraft Corporation proposed a modified Mirage IV variant as a replacement in July 1965 . The aircraft , known as the Mirage IV * or Mirage IVS ( S for Spey ) would be re - engined with more powerful Rolls - Royce Spey turbofan engines with a total of 41 , 700 lbs of thrust , larger ( fuselage depth increased by 3 inches , had an approximately 2 foot forward fuselage extension , and was to weigh 80 , 000 lb ) , and use avionics planned for the TSR - 2 , although BAC preferred the French Antilope radar . Although designed by Dassault , the production was to carried out jointly between Dassault and its subcontractors ( wing , mid - fuselage , and tail ) and BAC ( front and rear fuselage ) . The final assembly location was not determined before this proposal was rejected . The Mirage IV * was to carry a bombload of up to 20 , 000 lb . While the IV * was claimed to meet most of the RAFs requirements , and to be £1 million cheaper than the American - made F - 111 , the F - 111K was preferred ( only to be cancelled in turn ) and the Spey - engined Mirage abandoned . The Mirage IV * met nearly every RAF requirement except for field length , and some claim it exceeded the F - 111 slightly in speed and had at least equal range . The estimated cost was 2 . 321 million pounds per aircraft ( for 50 ) or 2 . 067 million ( for 110 ) , less than the price of the F - 111K . British Aircraft Corporation claimed that the British government evaluation into the Mirage IV * was " relatively superficial " . However , some British government officials , including Parliament members Julian Risdale and Roy Jenkins , questioned the Mirage IV * ' s capacity to operate from unprepared airstrips or to operate at low level , or claimed that the F - 111 was a superior aircraft " in a class of its own " . However , Bill Gunston notes that low - level Mirage IV missions had been planned since 1963 and Mirage IVs operated regularly at low level since 1965 , and argues that the ability of a strategic bomber to operate from unprepared airstrips is historically unimportant . Royal Air Force pilots who test - flew the Mirage IV were " favourably impressed " with its low level performance . BAC and Dassault had also hoped to sell the Mirage IV * to France and to export the Mirage IV * to various nations , such as India , possibly Israel , and others ; the lack of a British sale put an end to such possibilities . Some aviation journalists claim that the rejection of the Mirage IV * may have dampened French interest in joint Anglo - French cooperation . Design . The Mirage IV shares design features and a visual resemblance to the Mirage III fighter , featuring a tailless delta wing and a single square - topped vertical fin . However , the wing is significantly thinner to allow better high - speed performance and has a thickness / chord ratio of only 3 . 8 % at the root and 3 . 2 % at the tip ; this wing was the thinnest built in Europe at that time and one of the thinnest in the world . While being significantly smaller than an expensive medium bomber proposal for the role , the Mirage IV was roughly three times the weight of the preceding Mirage III . The Mirage IV has two SNECMA Atar turbojets in the rear fuselage , with air intakes on both sides of the fuselage that had intake half - cone shock diffusers , known as souris ( " mice " ) , which were moved forward as speed increased to trim the inlet for the shock wave angle . It can reach high supersonic speeds : the aircraft is redlined at Mach 2 . 2 at altitude because of airframe temperature restrictions , although it is capable of higher speeds . The aircraft has 14 , 000 liters ( 3 , 700 gal ( US ) ) of internal fuel , and its engines are quite thirsty , especially in afterburner . While the first Mirage IV prototype was fitted with double - eyelid engine nozzles , a more complicated variable geometry nozzle was adopted for production aircraft . The two - man crew , pilot and navigator , were seated in tandem cockpits , each housed under separate clamshell canopies . A bombing / navigation radar is housed within a radome in the fuselage under the intakes , aft of the cockpit ; much of the Mirage IV ' s onboard avionics systems , such as communications , navigational instrumentation , and bombing equipment , were produced by Thomson - CSF . A refueling probe is built into the nose ; aerial refuelling was necessary in most Mirage IV operations as the aircraft only had the fuel capacity , even with external drop tanks , to reach the Soviet Union ' s borders , thus refuelling was required to allow for a ' round trip ' . In the event of nuclear war between the major powers , it was thought that there would be little point in having the fuel to return as the host air bases would have been destroyed ; instead , surviving Mirage IVs would have diverted to land at bases in nearby neutral countries following the delivery of their ordnance . The Mirage IV has two pylons under each wing , with the inboard pylons being normally used for large drop tanks of 2 , 500 liter ( 660 gal ( US ) ) capacity . The outer pylons carry ECM and chaff / flare dispenser pods to supplement the internal jamming and countermeasures systems . On current aircraft , these are typically a Barax NG jammer pod under the port wing and a Boz expendables dispenser under the starboard wing . No cannon armament was fitted . The early Mirage IVA had a fuselage recess under the engines for a single AN - 11 or AN - 22 nuclear weapon of 60 kt yield . The Mirage IV can carry 12 solid - fuel rockets diagonally down below the wing flaps , for rocket - assisted take off ( RATO ) . From 1972 onward , 12 aircraft were also equipped to carry the CT52 reconnaissance pod in the bomb recess . The CT52 was available in either BA ( " Basse Altitude " , low - level ) or HA ( " Haute Altitude " , high - altitude ) versions with three or four long - range cameras ; a third configuration used an infrared line scanner . The CT52 had no digital systems , relying on older wet - film cameras . During the 1980s , a total of 18 Mirage IVs were retrofitted with a centreline pylon and associated equipment to carry and launch the nuclear ASMP stand - off missile . The Mirage IVA could theoretically carry up to six large conventional bombs at the cost of drop tanks and ECM pods , such armament was rarely fitted in practice . Operational history . Introduction and early operations . In February 1964 deliveries of the Mirage IV to the French Air Force started , with the first French Mirage IV strategic bombing squadron being declared operational on 1 October that year . The Mirage IV bomber force , when fully built up , consisted of three wings . These wings were each divided into three bomber squadrons , each with four Mirage IVs , each deployed at a different base to minimise the potential for an enemy strike to knock out the entire bomber force . These squadrons were : After establishment of its own deterrent force , the " Force de Dissuassion " , more commonly known as the " Force de frappe " , France withdrew from the military command structure of NATO in 1966 . French President Charles de Gaulle viewed the operational establishment of the Mirage IV fleet , a critical component of the independent " Force de frappe " , as highly influential to his decision to withdraw France from NATO , and that an independent French nuclear deterrent was necessary to ensure independence as a nation . From 1964 to 1971 , the Mirage IV was France ' s sole means of delivering nuclear ordnance , at this point they were armed with a single 60 kiloton nuclear bomb each . The primary objectives of the Mirage IVA force were major Soviet cities and bases . With aerial refueling , the plane was able to attack Moscow , Murmansk or Ukrainian cities from French bases . In order to refuel the Mirage IVA fleet , France purchased 14 ( 12 plus 2 spares ) U . S . Boeing C - 135 F tankers . Mirage IVAs also often operated in pairs , with one aircraft carrying a weapon and the other carrying fuel tanks and a buddy refueling pack allowing it to refuel its mate en route to the target . Even so , some sources state that some of the mission profiles envisioned were actually one - way , with the crew having no chance of returning after bombing a Soviet city . Initially , the basic attack flight profile was " high - high - high " at a speed of Mach 1 . 85 , engaging targets up to a maximum radius of 3 , 500 km ( 2 , 175 mi ) . In the late 1960s , when the threat of surface - to - air missile defences made high - altitude flight too hazardous , the Mirage IVA was modified for low - altitude penetration . Flying low , the maximum attack speed was reduced to 1 , 100 km / h ( 680 mph ) and the combat radius was also decreased . By the 1970s it was clear that vulnerability of the Mirage IV to air defences , even in low - level flight , made the delivery of gravity bomb s such as the " AN - 11 " or " AN - 22 " impractical . As more of the deterrent role was passed to land - based IRBM s and submarine - based missiles , one wing of Mirage IVs was stood down in 1976 . Upgrades and decline . In 1973 , it was reported that a force of 40 Mirage IVs would continue to perform as a part of France ' s national nuclear deterrent until the 1980s , and that steady improvements were to be undertaken . In 1979 , in response to the decreasing effectiveness of the free - fall bombs used by both its strategic and tactical nuclear forces , the French commenced development of the ASMP stand - off missile , with a range of up to 400 km ( 250 mi ) and a single 150 or 300 kt nuclear warhead . Eighteen Mirage IVAs were modified to carry the new weapon instead of bombs and received the new designation Mirage IVP ( Penetration ) . The first Mirage IVP flew on 12 October 1982 and entered service on 1 May 1986 . This variant could carry either a single missile or a reconnaissance pod on the centreline . In August 1985 , a French proposal that would have seen Mirage IVPs stationed at air bases inside neighbouring West German was made public ; this deployment would have marked a significant philosophical departure from traditional French nuclear defence policy . On 31 July 1996 , the Mirage IVP was formally retired in its bomber capacity , the nuclear mission having been transferred from the Mirage IV to the newer Dassault Mirage 2000N . EB 2 / 91 was disbanded and EB 1 / 91 was redesignated " Escadron de Reconnaissance Stratégique " ( Strategic Reconnaissance Squadron ) , using the 12 remaining Mirage IVPs . In the reconnaissance role , the Mirage IVP has seen service over Bosnia , Iraq , Kosovo , and Afghanistan . ES 1 / 91 Gascogne ' s surviving Mirage IVPs were retired in 2005 and are conserved and stored at the " Centre d ' Instruction Forces Aériennes Stratégiques " ( CIFAS ) at Bordeaux Mérignac . The retirement of all reconnaissance - configured Mirage IVPs in 2005 meant that the Armée de l ' Air ' s Mirage F1 CRs were for some time the only aircraft capable of carrying out aerial reconnaissance missions . The long term replacement for the Mirage IVP was Mirage 2000N aircraft outfitted with a modern PRNG " Pod de Reconnaissance Nouvelle Génération " ( New Generation Reconnaissance Pod ) , equipped with digital camera equipment . The Mirage IV had been popular with its crews , who found it enjoyable to fly despite its antiquated systems and generally uncomfortable cockpit . In addition , it required surprisingly little maintenance considering its age and complexity . Royal Air Force pilots who flew the Mirage IV at the Mont de Marsan airbase during its evaluation for the proposed Mirage IV * variant were " favourably impressed " with its low level performance .