Dassault Mirage IV
During the 1950s, France embarked on an extensive military program to produce nuclear weapons; however, it was acknowledged that existing French aircraft were unsuitable for the task of delivering the weapons. Thus, the development of a supersonic bomber designed to carry out the delivery mission started in 1956 as a part of the wider 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-metre-long nuclear bomb 2,000 km (without aerial refuelling). According to aviation authors Bill Gunston and Peter Gilchrist, the specification's inclusion of supersonic speed was "surprising" to many at the time.
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 47 kilonewtons (10,500 lbf) thrust SNECMA Atar engines and a combat radius of 2,700 kilometres (1,700 mi) 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 and the unbuilt Mirage II interceptor. In April 1957, Dassault were informed that they had won the design competition.
Dassault's resulting prototype, dubbed Mirage IV 01, looked a lot like the Mirage IIIA, 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 20 metres (67 ft) long, had an 11 metres (37 ft) wingspan, 62 square metres (670 sq ft) of wing area, and weighed approximately 25,000 kilograms (55,000 lb). It was considerably more advanced than the 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. At the time, no aircraft had been designed to cruise at over Mach 1.8 for long periods of time and there were sizable technological and operational uncertainties. Weapon-related issues were another issue. Building the 01 in Dassault's Saint-Cloud plant near Paris took 18 months. In late 1958, the aircraft was transferred to the Melun-Villaroche flight testing area for finishing touches and ground tests. On 17 June 1959, French General Roland Glavany, on a five-year leave from the French Air Force since 1954, took the 01 for its maiden flight.
Dassault Mirage IV
During the 1950s, France embarked on an extensive military program to produce nuclear weapons; however, it was acknowledged that existing French aircraft were unsuitable for the task of delivering the weapons. Thus, the development of a supersonic bomber designed to carry out the delivery mission started in 1956 as a part of the wider 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-metre-long nuclear bomb 2,000 km (without aerial refuelling). According to aviation authors Bill Gunston and Peter Gilchrist, the specification's inclusion of supersonic speed was "surprising" to many at the time.
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 47 kilonewtons (10,500 lbf) thrust SNECMA Atar engines and a combat radius of 2,700 kilometres (1,700 mi) 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 and the unbuilt Mirage II interceptor. In April 1957, Dassault were informed that they had won the design competition.
Dassault's resulting prototype, dubbed Mirage IV 01, looked a lot like the Mirage IIIA, 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 20 metres (67 ft) long, had an 11 metres (37 ft) wingspan, 62 square metres (670 sq ft) of wing area, and weighed approximately 25,000 kilograms (55,000 lb). It was considerably more advanced than the 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. At the time, no aircraft had been designed to cruise at over Mach 1.8 for long periods of time and there were sizable technological and operational uncertainties. Weapon-related issues were another issue. Building the 01 in Dassault's Saint-Cloud plant near Paris took 18 months. In late 1958, the aircraft was transferred to the Melun-Villaroche flight testing area for finishing touches and ground tests. On 17 June 1959, French General Roland Glavany, on a five-year leave from the French Air Force since 1954, took the 01 for its maiden flight.