The Dassault Balzac V was a French vertical takeoff and landing (

VTOL A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wi ...

) testbed of the early 1960s. It was built by

Dassault Aviation Dassault Aviation SA () is a French manufacturer of military aircraft and business jets. It was founded in 1929 by Marcel Bloch as Société des Avions Marcel Bloch or "MB". After World War II, Marcel Bloch changed his name to Marcel Da ...

from a prototype Mirage III aircraft to test the configuration for the Mirage IIIV. The sole example was badly damaged during an accident that occurred during its second flight test and was not repaired.

Design and development

Since the

Rolls-Royce RB162 The Rolls-Royce RB.162 is a lightweight British turbojet engine produced by Rolls-Royce Limited. Developed in the early 1960s, it was specially designed for use as a lift engine for VTOL aircraft but was also used in a later variant of the Ha ...

lift engines specified for the Mirage IIIV were not expected to be available before 1963, Dassault modified the first Mirage III prototype to serve as an interim VTOL testbed. Eight Rolls-Royce RB108 lift engines were installed, each with an average maximum takeoff thrust of 9.83 kN (2,210 lbf). The Mirage III's Snecma Atar G.2 propulsion engine was replaced with an unreheated (non-afterburning)

Bristol Siddeley Orpheus The Bristol Siddeley Orpheus was a single-spool turbojet developed by Bristol Siddeley for various light fighter/trainer applications such as the Folland Gnat and the Fiat G.91. Later, the Orpheus formed the core of the first Bristol Pegasus ...

BOr 3 with a

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...

of 21.57 kN (4,850 lbf). The lift engines were grouped in tandem pairs around the aircraft's

center of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...

on either side of the propulsion engine's intake duct, with each pair in a row separated by the main undercarriage wheelbays.

Operational history

The Balzac V began tethered hovering on 12 October 1962 and achieved the first free hover only six days later, two months ahead of schedule. The first accelerating transition from vertical takeoff to horizontal flight took place on its seventeenth sortie on 18 March 1963. The aircraft crashed on 10 January 1964, on its 125th sortie, during a low-altitude hover. During a vertical descent the aircraft experienced uncontrollable divergent wing oscillations, the port wing eventually striking the ground at an acute angle with the aircraft rolling over because of the continued lift engine thrust. The loss was attributed to loss of control because the stabilising limits of the three-axis autostabilisation system's 'puffer pipes' were exceeded in roll. Although airframe damage was relatively light, the ''Centre D'Essai en Vol'' test pilot, Jacques Pinier, did not eject and died in the crash. The aircraft was rebuilt, and resumed flight testing on 2 February 1965. On 8 September 1965, the aircraft suffered another fatal crash, once again while in a low altitude hover. The aircraft was being evaluated by

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Si ...

Major P. E. Neale, as part of a Franco-American information exchange on VTOL programmes. Major Neale made an unsuccessful ejection outside the ejection seat's escape envelope. The findings of the accident investigation were never made public. It was speculated that hydraulic control difficulties coupled with excessive use of the lift engines resulted in fuel starvation and the flameout of all nine engines. Once again, the damage was not irreparable, but this time the aircraft was not rebuilt, as flight development of the Mirage IIIV prototype was already underway. The Balzac V gained its name from the co-incidence of its serial number (001) with the telephone number (BALZAC 001) of a well-known Paris movie advertising agency (Publicité Jean Mineur).Fricker, John. "Mirage might have beens 2: Balzac - Dassault's first VTOL variant". ''Air International'' 45 (5), November 1993: pp. 268–274.

Specifications (Balzac V)

References

Bibliography

* Breffort, Dominique and Andre Jouineau. "The Mirage III, 5, 50 and Derivatives from 1955 to 2000." ''Planes and Pilots 6''. Paris: Histoire et Collections, 2004. . *Buttler, Tony and Jean-Louis Delezenne. ''X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974''. Manchester, UK: Hikoki Publications, 2012. * * Green, William. ''Macdonald Aircraft Handbook''. London. Macdonald & Co. (Publishers) Ltd., 1964. * Pérez, San Emeterio Carlos. ''Mirage: Espejismo de la técnica y de la política'' (in Spanish). Madrid: Armas 30. Editorial San Martin, 1978. .

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