SNCAC NC 1080

TheSNCAC NC 1080 was a Frenchjet-engined interceptor developed in the late 1940s bySNCAC for use aboardaircraft carriers. It was intended to compete for anAéronavale (French Naval Aviation) contract and first flew in 1949. The aircraft used an innovative system offlight control surfaces that proved to be a failure during flight testing and had to be modified before it could fly again. Its development was troubled by other design flaws and the company's merger withSNCAN that same year. Further development was cancelled after a fatal crash destroyed the soleprototype in 1950.

SNCAC NC 1080
The prototype of the NC.1080 in 1950
General information
Type	Interceptor
National origin	France
Manufacturer	SNCAC (Société Nationale de Constructions Aéronautiques du Centre)
Status	Cancelled
Number built	1
History
First flight	29 July 1949

Development and description

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After the end of World War II, Aéronavale had only two small aircraft carriers:Dixmude, which was loaned by the Americans, andArromanches, which had been leased from the British, but planned tolay down its own larger PA-28 design in 1947. All of its aircraft werepiston-engined and had been rendered obsolete by the advent of jet-propelled aircraft during the war. The French lacked an indigenousturbojet design andlicensed the BritishRolls-Royce Nene to facilitate their development of jet-propelled aircraft.^[1] Aéronavale issued a requirement for a jet-powered interceptor on 29 March 1946 and then issued arequest for proposals on 8 June. The aircraft had to exceed a speed of 900 km/h (559 mph) at all altitudes, have a climb rate in excess of 25 m/s (82 ft/s) atsea level, and an armament of three 30-millimeter (1.2 in)autocannon with the possibility of carrying bombs or unguidedair-to-ground rockets. TheNord 2200 andArsenal VG 90 were the other competitors for the contract for 90 aircraft.^[2]

The single-seat SNCAC NC 1080 had alow-mounted single-spar wing that wasswept back at an angle of 22° 30'. Its circular-sectionfuselage was built in two parts and the fuel tank was housed in the forward section with a total capacity of 1,950liters (429 imp gal; 515 U.S. gal). It was fitted with aradar in the nose,tricycle landing gear and folding wings. Air for the 22.2-kilonewton (5,000 lb_f) Nene 102 engine was provided by semi-elliptical intakes on the sides of the fuselage and usedboundary layer suction to smooth the airflow.^[3] Most unusually, the aircraft lackedailerons and lateral control was intended to be provided by "compensators", combinationdouble-slotted andblown flaps designed by Pierre-Marcel Lemoigne, andspoilers in the wings; the spoilers were also intended to act asdive brakes when deployed below the wings.^[4] The entire aft fuselage could be removed to allow access to the engine. Thecockpit was armored and the pilot was provided with anejection seat.^[5]

Construction and flight testing

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Aéronavale awarded SNCAC a contract on 31 December 1946,^[6] but cancelled it two years later under budgetary constraints. The company decided to continue work at its own expense, still hoping for a production order.^[5] The prototype was completed in March 1949 with temporary fixed landing gear and it was trucked toToussus-le-Noble Airport, but flight testing was delayed by the late delivery of the retractable landing gear.^[7]Taxiing trials began on 23 June and a few short hops were made during high-speed taxiing two days later. These revealed problems withlateral stability which caused the aircraft'svertical stabilizer andrudder to be heightened and small plates to be added at thewingtips.^[8]

While these modifications were being made, SNCAC went bankrupt in July and merged withSNCAN (later Nord Aviation). The NC 1080 made its officialmaiden flight on 29 July from the airfield atMelun Villaroche while its fate was being decided. The flight demonstrated that thewind-tunnel testing of the prototype's novel control surfaces had been grossly inadequate as the spoilers and compensators were almost entirely useless and it was still only marginally stable laterally. The test pilot found the aircraft almost impossible to turn, but was able to land atBrétigny-sur-Orge Air Base after eight minutes of flight only because it was almost straight ahead from Melun Villaroche. SNCAN considered terminating the program after the flight, flying its own competitor for the requirement, but it was awarded a contract by Aéronavale later that year to continue development.^[9]

SNCAN's engineers replaced the spoilers with ailerons and moved the wingtip plates to the tips of thehorizontal stabilizers. The prototype was flown back to Melun Villaroche on 16 December and it resumed flight testing in January 1950. The following month servomotors were installed to boost the aileron controls and the boundary layer suction system was removed. The manufacturer's trials were completed in March after 19 more flights and the aircraft was flown back to Brétigny-sur-Orge on 31 March to begin its official trials at theCentre d'essais en vol (Flight Test Center). It reached a speed of 720 km/h (450 mph) and a speed ofMach 0.64 in a dive during flights on 6 April. The following day the NC 1080 entered aspin at an altitude of 3,000 m (9,800 ft), had its anti-spin parachute torn away, and crashed, killing the pilot, Pierre Gallay. Witnesses saw pieces fly off the aircraft, but the subsequent investigation was unable to determine why it crashed. Without another prototype available to continue development, the program was cancelled and a license-built version of the Britishde Havilland Sea Venom was ultimately selected to satisfy Aéronavale's requirement.^[10]

Specifications

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Data fromX-Planes of Europe II: Military Prototype Aircraft from the Golden Age 1945–1974^[11]

General characteristics

Crew: 1
Length: 12.87 m (42 ft 3 in)
Wingspan: 12 m (39 ft 4 in)
Wing area: 28.4 m² (306 sq ft)
Gross weight: 7,800 kg (17,196 lb)
Fuel capacity: 1,950 liters (429 imp gal; 515 U.S. gal)
Powerplant: 1 ×Rolls-Royce Nene 102 centrifugal-flow turbojet engine, 22.2 kN (5,000 lbf) thrust

Performance

Maximum speed: 977 km/h (607 mph, 528 kn) at 5,000 m (16,000 ft) (designed)
Maximum speed: Mach 0.85
Range: 1,300 km (810 mi, 700 nmi) (designed)
Service ceiling: 12,700 m (41,700 ft) (estimated)
Rate of climb: 28 m/s (5,500 ft/min) atsea level (intended)
Time to altitude: 11 minutes, 20 seconds to 9,000 m (30,000 ft)

Armament

Guns: 3 × 30 mm (1.2 in) autocannon (planned)

References

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^Gaillard, pp. 14–15
^Carbonel, pp. 100–101
^Buttler, pp. 91, 93
^Gaillard, pp. 16–17
^^a ^bCarbonel, p. 104
^Gaillard, p. 16
^Gaillard, p. 17
^Buttler, p. 90
^Buttler, pp. 90–92; Gaillard, p. 18
^Buttler, pp. 91–92; Gaillard, pp. 18–19
^Buttler, pp. 90, 93

Bibliography

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Buttler, Tony.X-Planes of Europe II: Military Prototype Aircraft from the Golden Age 1946–1974. Manchester, UK: Hikoki Publications, 2015.ISBN 978-1-90210-948-0
Carbonel, Jean-Christophe.French Secret Projects 1: Post War Fighters. Manchester, UK: Crecy Publishing, 2016ISBN 978-1-91080-900-6
Gaillard, Pierre (April 1995). "Les trois premiers chasseurs embarqués à réaction français, 1 — Le NC 1080" [The First Three French Carrier Jet Fighters, 1 — The NC 1080].Le Fana de l'Aviation (in French) (305):12–19.ISSN 0757-4169.