NBMR-1

NBMR-1
The winning entry, Fiat G.91 lightweight strike fighter
Project for	Development of military aircraft
Issued by	NATO
Date initiated	1953
Prototypes	Breguet Taon Br.1001 Dassault Mystère XXVI Fiat G.91
Date concluded	1958
Outcome	G.91 officially declared winner
Successor programs	NBMR-3

NATO Basic Military Requirement 1 (NBMR-1) was a document produced by a North Atlantic Treaty Organisation (NATO) committee in the 1950s detailing the specification of future combat aircraft designs. The requirement was for a "light weight tactical strike fighter (LWTSF)" capable of operating from rough airfields, delivering either conventional or tactical nuclear weapons, and being simple to maintain.

Specification

In December 1953, NATO Supreme Command issued specifications for a new light tactical support aircraft. Aircraft manufacturers within NATO countries were invited to submit their designs for this requested Light Weight Strike Fighter role. The competition was intended to produce an aircraft that was light, small, expendable, equipped with basic weapons and avionics and capable of operating with minimal ground support. These specifications were developed for two reasons: the first was the nuclear threat to large air bases, many cheaper aircraft could be better dispersed, and the other was to counter the trend towards larger and more expensive aircraft.

The technical requirements were:

• 1,100 m (3,600 ft) takeoff distance over a 15 m (49 ft) obstacle
• Capability to operate from grass strips and roads
• Maximum speed of Mach 0.95
• Range of 280 km (170 mi) with 10 minutes over the target
• Armoured protection for the pilot and the fuel tanks
• 4 × 12.7 mm (0.50 in) or 2 × 20mm or 30mm guns
• A maximum of 2,200 kilograms (4,900 lb) empty weight and 4,700 kilograms (10,400 lb) max weight

The challenge of providing an engine that matched the requirements of lightness and power, reliability and ease of maintenance was solved by using the Bristol Siddeley Orpheus turbojet. The development of the Orpheus was funded from the US Mutual Weapons Development Program which was a way for the US to support weapons procurement for members of the NATO alliance.

Submissions and selections

Designs were submitted by manufacturers from many NATO countries, including France, Italy and the United States. The designs were required within two months of the competition. The special committee had to choose from eight projects, including the Aerfer Sagittario 2 (Italy), Breguet Br.1001 Taon (France), Dassault Mystère XXVI (France), Fiat G.91 (Italy), Northrop N-156 (USA) and Sud-Est Baroudeur (France). Although its development is considered a factor which motivated NATO to issue the requirement, the Folland Gnat itself was not evaluated in the competition. These designs were assessed starting on 18 March 1953 by AGARD under the leadership of Theodore von Kármán.

Project selections took 18 months to complete. The first result was announced on 30 June 1955: the winning projects were, in order: the Breguet Br. 1001 Taon, Fiat G.91 and a third, the Mystère XXVI, three prototypes of this design were also ordered. The G.91 first flew on 9 August 1956 at the Caselle airfield, Turin, in the hands of Chief Test Pilot Riccardo Bignamini. Dassault flew the Mystère XXVI, now named Étendard VI, piloted by Gérard Muselli on 15 March 1956 at Melun Villaroche Aerodrome, followed by the Breguet Taon on 26 July 1957.

The final selection of the competing designs was planned for late 1957, accordingly in September 1957 the three rival aircraft types met for evaluation trials, at the Centre d'Essais en Vol at Brétigny-sur-Orge in France,. During the trials the Italian aircraft performed impressively and, in January 1958, the Fiat G.91 was officially declared the winner.

Outcome

Following a meeting of NATO Defence Ministers in April 1958 it was agreed that the G.91 would be the first NATO lightweight strike fighter, it would be followed in 1961 by the Breguet Taon. A production meeting was planned for May 1958 to discuss the production of the aircraft with financial support from the United States. The Americans agreed to provide some of the finance for the French, German and Italian aircraft and pay for the planned Turkish aircraft.

Given the large economic and commercial interests at stake, there was a certain amount of controversy surrounding this decision. After the loss of the G.91 prototype due to aeroelastic vibration on 20 February 1957, the French government preferred to pursue development of the locally-designed Étendard. The British government similarly ignored the competition to concentrate on Hawker Hunter production for the same role. The Italian government also ordered the G.91 for the Italian Air Force before the results of the competition were known.

In the end, the German German Air Force (Luftwaffe) placed the largest order based on the competition. The Luftwaffe was originally to have received fifty G.91R and twenty G.91T two-seaters from the Fiat production lines and a further 232 G.91R manufactured under licence in Germany by the Dornier, Messerschmitt and Heinkel companies (Arbeitsgemeinschaft G.91.) The licence production was subsequently increased to 294 aircraft, bringing the total to 344. The G.91R/3 equipped four newly formed Leichte Kampfgeschwader ("light attack wings"), often replacing former Republic F-84F Thunderstreak units.

The G.91 was to be replaced in the 1960s by the winner of the NBMR-3 competition for VSTOL aircraft but that did not result in a common aircraft design. In the end, the last G.91s were retired by Germany in 1982 and Italy in 1995 respectively, while the final Dassault-Breguet Super Étendard, the ultimate derivative of the unsuccessful Étendard VI, will serve with the French French Naval Aviation (Aéronavale) until 12 July 2016.

See also

• Light fighter
• Lightweight Fighter program

References

Citations

Bibliography

• Angelucci, Enzo and Paolo Matricardi. Combat Aircraft 1945–1960. Maidenhead, Berkshire, UK: Sampson Low Guides, 1980. ISBN 0-562-00136-0.
• Crosby, Francis. Fighter Aircraft. London: Lorenz Books, 2002. ISBN 0-7548-0990-0.
• Ferrari, Massimo. "Addio G.91R" (in Italian). RID magazine, August 1992.
• Jackson, Paul A. German Military Aviation 1956-1976. Hinckley, Leicestershire, UK: Midland Counties Publications, 1976.ISBN 0-904597-03-2
• Niccoli, Riccado. "Fiat G.91, NATO's Lightweight Fighter" International Air Power Review. Volume 7, Winter 2002.