Dassault Mirage IIIV
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| Mirage IIIV | |
|---|---|
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| Type | VTOL fighter aircraft |
| Manufacturer | Dassault Aviation |
| Maiden flight | February 1965 |
| Primary user | French Air Force |
| Produced | 1965-1966 |
| Number built | 2 |
| Developed from | Dassault Mirage III |
The French Dassault Mirage IIIV (three vee) fighter aircraft was one of the most interesting offshoots of the Dassault Mirage III family tree. A vertical take-off and landing (VTOL) fighter, the IIIV featured eight small vertical lift jets straddling the main engine. The design was in response to a mid-1960s NATO specification for a VTOL strike fighter.
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[edit] Balzac V
Since the Rolls-Royce RB.162 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 RB.108 lift engines were installed, each with an average maximum take-off thrust of 9.83 kN (2,210 lbf). The Mirage III's SNECMA Atar G.2 propulsion engine was replaced with an unreheated Bristol Orpheus BOr 3 with a thrust of 21.57 kN (4,850 lbf). The lift engines were grouped in tandem pairs around the aircraft's center of gravity on either side of the propulsion engine's intake duct, with each pair in a row separated by the main undercarriage wheel bays.
The Balzac began tethered hovering on October 12, 1962 and achieved the first free hover only six days later, two months ahead of schedule. The first accelerationg transition from vertical take-off to horizontal flight took place on its 17th sortie on March 18, 1963.
The aircraft crashed on January 10, 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, Jaques Pinier, did not eject and died in the crash.
The aircraft was rebuilt, and resumed flight testing on February 2, 1965. On September 8, 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 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 flame-out 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 (Vertical) 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).[1]
[edit] NATO competition
Four designs were submitted, the Mirage IIIV design, the Fokker-Republic D.24 Alliance, the BAC 584 and the Hawker P.1154, to NATO in January 1962 in competition for the AC/169 specification for a supersonic V/STOL strike fighter to meet NATO Basic Military Requirement 3. In May that year the resulting judgement that the P.1154 was the technically superior, but when considering as well the financing and work-sharing opportunities the Mirage IIIV was judged its equal in merit[citation needed]. NATO was not in the position to fund the full development of either winner leaving it up to the individual member countries[citation needed].
[edit] Mirage
In the meantime, the Balzac had led to the actual Mirage IIIV, which was twice as big. Two prototypes were built. The first Mirage IIIV performed its first hovering trial in February 1965. The IIIV had the general layout of earlier Mirage fighters, but it was longer and had a bigger wing, and, like the Balzac, nine engines: a single SNECMA-modified Pratt & Whitney JTF10 turbofan, designated TF104, with thrust of 61.8 kN (13,900 lbf), and eight Rolls-Royce RB.162-1 engines, each with thrust of 15.7 kN (3,525 lbf), mounted vertically in pairs around the centreline. The TF-104 was originally evaluated on a special-built trials machine, the Mirage IIIT, which was much like a Mirage IIIC except for the change in engine fit.
The TF104 engine was quickly replaced by an upgraded TF106 engine, with thrust of 74.5 kN (16,750 lbf), before the first prototype made its initial transition to forward flight in March 1966. It later attained Mach 1.32 in test flights.
The second prototype featured a TF30 turbofan for forward thrust of 82.4 kN (18,500 lbf), and first flew in June 1966. In September of that year, it attained Mach 2.04 in level flight, but was lost in an accident on 28 November 1966. The Mirage IIIV never was able to take off vertically and successfully go supersonic in the same flight; the thirsty and heavy lift jets prevented it[citation needed].
The loss of the second prototype effectively killed the program, and in fact killed any prospect of an operational Mach 2 vertical take-off fighter for decades. The British Hawker P.1154 had been cancelled in 1965 by the government just as the prototypes were being built, though its subsonic brother, the Hawker-Siddeley Kestrel VTOL attack aircraft was flying in tri-partite trials with the UK, US and West Germany. The French preferred the Mirage IIIV, and the international cooperation needed to make the P.1154 a reality never materialized.
Some of the P.1154 work contributed to the final operational vertical take-off fighter based on the Kestrel, the highly successful Harrier. The Mirage IIIV was never a realistic combat aircraft. The eight lift engines would likely have been a maintenance nightmare, and certainly their weight imposed a severe range and payload penalty on the aircraft. Apparently the program was all but dead even before the loss of the second prototype[citation needed].
A piece of the technology of the IIIV was re-used in the extremely successful Mirage IIIF, later Mirage F1. The cockpit and ancillary electronics found a home in what has become one of the most successful French interceptors after the illustrious Mirage III[citation needed].
[edit] Specifications (Mirage IIIV)
Data from[citation needed]
General characteristics
- Crew: 1
- Length: 16.30 m (53 ft 6 in)
- Wingspan: 8.80 m (28 ft 10 in)
- Height: m (ft)
- Wing area: ()
- Empty weight: 6,750 kg (14,880 lb)
- Powerplant:
- 1× Pratt & Whitney TF106 turbofan, 17,600 lbf (78.5) kN
- 8× RollsRoyce RB162 turbofans, 4,400 lbf (19.6 kN) each
Performance
- Maximum speed: (Mach 2)
[edit] See also
Related development
Comparable aircraft
Related lists
[edit] References
- ^ Fricker, John (November 1993). "Mirage might have beens 2: Balzac - Dassault's first VTOL variant". Air International 45 (5): 268–274.
[edit] External links
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