Even in the face of total devastation at the hands of the German invasion of World War 2 (1939-1945), French aviation industry rebounded rather effectively during the post-war years to lay the groundwork for some of the most impressive developments of the Cold War period. Even during the war, French aviation engineers continued work on various aircraft-related projects and some of these were realized in the immediate years following the close of World War 2 in Europe while others gestated for quite some time.
Further on, French industry began delving into more advanced concepts now that the smoke of total war had settled. Dassault Aviation, a concern finding its start in 1929 under the leadership of Marcel Dassault himself, managed to survive the war and introduced their MD 315 transport as soon as 1948. However, its greatest splash of the early Cold War years came with the introduction of the popular Mirage III interceptor of 1956. This fine platform was brought online during 1961 and 1,422 were ultimately produced, serving a bevy of foreign operators during its time aloft (some continued to fly with Pakistan).
With the Mirage III airframe at its disposal, Dassault engineers began pursuit of a Vertical Take-Off and Landing (VTOL) prototype during the early part of the 1960s. It was decided to utilize a combination propulsion method in which a primary turbojet would provide the power for forward motion and a series of smaller "lift" engines would provide the force needed to hover. A Bristol Siddeley Orpheus 3 series engine of 5,000lb thrust output became the solution for the former and eight Rolls-Royce RB.108 lift engines were used to satisfy the latter requirement. On the whole, the general appearance of the Mirage III airframe was retained including its forward cockpit, single vertical tail fin, and delta-wing planform. However, the fuselage had to be widened to accept the new internal engine arrangement (engines and related ductwork) and a large part of the fuselage was, in fact, reworked when compared to the original Mirage III series.
The primary forward-motion engine was to use existing side-mounted intakes, represented along the sides of the cockpit as semi-circular openings featuring fixed shock cones. The lift engines would require individual intake openings at their respective positions and these were fulfilled by Rolls-Royce-designed retractable components. During forward flight, these engines would be automatically faired over so as not to disrupt the aircraft's general air flow. Onboard fuel stores allowed for roughly twelve minutes of hovering flight time.
As finalized, the aircraft lost its Mirage III name and became the Dassault "Balzac V" with the official name of the sole prototype ultimately being "Balzac 001".
Ground running began in late July of 1962 and tethered testing followed in October of that year. At this time, the undercarriage remained fixed for simplicity's sake. On October 18th, the first untethered flight was accomplished and several more untethered flights followed before the end of the year and the aircraft was finally given a fully-fledged retractable undercarriage arrangement to test traditional horizontal flight envelopes - the first such flight recorded on March 2nd, 1963. On March 18th, the aircraft completed its first vertical-to-horizontal flight conversion test and landed in a conventional fashion on the runway. A successful horizontal-to-vertical landing action was made on March 28th. Modifications instituted during 1963-1964 added a unique short take-off capability by way of deflectors installed - the Balzac now showcases short-field take-off qualities.
The aircraft program proceeded with nary a setback until January 10th, 1964 when the aircraft turned over during a hovering action and landed on its dorsal spine. The pilot, Jacques Pinier, ultimately died from his injuries. The accident was blamed on a loss of control due to the autostabilization system. Despite being damaged and its test pilot killed, the Balzac airframe was saved to move the program along into 1965.
The Balzac completed some additional evaluation flights before a September 1965 accident once again threatened the project. At this point, the Balzac was part of a VTOL technology exchange between the French and the Americans. USAF pilot P.E. Neale was at the controls during a low hovering action which went awry. He managed to eject prior to the airframe crashing from a total engine flameout, but died when impacting the ground as he had ejected under the recommended altitude minimum. Unlike the first accident, this one was to claim both pilot and aircraft - ending the Balzac program in full.
Dassault was to continue further research into VTOL aircraft through its new Mirage IIIV offering. Two of the type were ultimately built and these based largely on the work already completed through the Balzac (including its independent lift/push engine arrangement). First flight was on February 12th, 1965 and the aircraft was developed along the lines of a new NATO VTOL aircraft requirement but was not adopted before the end.
Despite the loss of both life and aircraft - always the unwritten price to be paid for pioneering development aircraft - the Balzac provided important insight into VTOL flight for the French. For warplanners, the future was always full of supersonic fighter jets holding an inherent helicopter-like capability. While this would not be truly realized until the adoption of the British Harrier jet, it fell to aircraft like the French Balzac to help further the concept along, ensuring that the sacrifices emerging from such programs would never be forgotten and ultimately realized in fully-flying forms.