Origins and prototypes
In August 1960, the Air Force general staff drew up the operational requirements for a supersonic VTOL (vertical take-off and landing) combat aircraft. Intended for penetration missions (reconnaissance and airbase raids), this aircraft was to replace the Mirage III E in 1967. In September 1960, GAMD’s Mirage III V project was accepted.
At the request of the Defense minister, Dassault and Sud-Aviation decided to build it. As the configuration was such a novel one, the two corporations resolved to progress prudently, in two proposed stages:
- first, to prove the feasibility of the configuration by using existing turbo-jets in subsonic flight : whence the Balzac V ;
- subsequently to fly a Mach 2 aircraft equipment with more powerful lift and propulsion rockets, then still at the design stage : this was the Mirage III V.
On February 2, 1961, the DTIA notified GAMD and Sud-Aviation that it was ordering an experimental vertical take-off Balzac V.
Lift was to be provided by eight Rolls-Royce RB 108 turbo-jets of 9.8kN thrust each, mounted almost vertically two by two in four compartments of the aircraft on either side of the air duct of the propulsion engine, a 21.6-kN Bristol Siddeley Orpheus 3.
The lift jets were to be supplied with air via four intakes situated above the fuselage, while their exhaust pipes would be situated above the fuselage, while their exhaust pipes would be situated in apertures with blanking caps which would be closed during normal raid flight.
The new aircraft, used part of the wing from Mirage III 001 Balzac and a fuselage designed and built in collaboration with Sud-Aviation. It was an experimental single-seater for the study and development of the vertical take-off Mirage III V. It carried neither weapons nor operational equipment.
The technical difficulties had been effectively separated out: since the conventional flight performance of the Mirage III was well documented, it only remained to study the vertical take-off and landing and the transitional stages. This was the beginning of modern flight controls (absence of linkage and redundancy). Balzac V 001 was also the first aircraft to transmit flight data to the ground by telemetering.
At Melun-Villaroche on October 12, 1962, René Bigand made the first stationary flight. The aircraft was attached by nylon cables fixed to the front lifting point and the main landing gear. A second tethered flight was made on the same day and a third on the 15th. On October 18, the first low-level free flight was made, and on the 25th, during its third free flight, the aircraft remained in hovering flight, for more than two minutes. On March 18, 1963, for its 17th sortie, it made its first transition accelerating from vertical flight to horizontal flight and on the 29th the first complete cycle: vertical take-off, horizontal flight and vertical landing.
The aircraft was subsequently tested by several pilots from the light Test Center and the US Air Force. All of them confirmed the quality of the technical performance, but emphasized that the configuration was highly complex. This analysis, which the Corporation shared, was tragically illustrated by two fatal accidents.
The vertical program was shelved in 1966. If the officially-dictated formula was indeed attractive, it was hard to put into practice. The lift jets were costly and unable to deliver enough thrust. Also, this type of aircraft’s limited warhead capabilities and range, paired with its need for substantial ground logistics, hampered its versatility.
|Unladen weight||5 360 kg|
|Max. Speed Top Mach||0.90|
|Type||Lift : 8 RR RB 108 / Propulsion 1 Bristol Orpheus 3|
|Lift : 8 RR RB 108 / Propulsion 1 Bristol Orpheus 3||8x 1000 kgp – 1×2200 kgp / 8×9.8 kN 1×21.6 kN|