Nord 1500 Griffon

https://en.wikipedia.org/wiki/Nord_1500_Griffon

The Nord 1500 Griffon was an experimental ramjet-powered fighter aircraft
designed and built in the mid-1950s by French state-owned aircraft manufacturer
Nord Aviation. It was part of a series of competing programs to fill a French
Air Force specification for a Mach 2 fighter.

Design of the Griffon originated in a late 1940s requirement for a high speed
interceptor. Engineers at Arsenal de l'Aéronautique instigated studies into
swept and delta wings using supersonic gliders, the Arsenal 1301 and Arsenal
2301. Results from these flight tests favoured the delta configuration, which
was incorporated into design studies using a variety of powerplants. By this
time Arsenal had been privatised as SFECMAS - Société Française d'Etude et de
Construction de Matériel Aéronautiques Spéciaux. Powered by a large ramjet with
turbojet sustainer, the Griffon was renamed from the SFECMAS 1500 Guépard
(Cheetah) after SFECMAS was merged with SNCAN to form Nord Aviation.

Two prototypes were ordered initially in a letter dated 24 August 1953, with the
final contract, (No. 2003/55) in 1955. Although intended to eventually fulfil a
requirement for a light interceptor capable of operation from 1,000m grass
runways, the two prototypes were ordered without military equipment for research
purposes only.

Constructed mainly of light alloys, the Griffon comprised a large tubular
fuselage which supported the middle set delta wings, fin with rudder and the
forward fuselage, which extended forwards over the turbo-ramjet air intake. The
forward fuselage housed the single-seat cockpit and carried small delta canards
on either side of the cockpit. The tricycle undercarriage retracted into the
wings and the underside of the air intake.

The design of the Griffon featured a dual turbojet-ramjet powerplant, with the
turbojet enabling unassisted takeoffs (ramjets cannot produce thrust at zero
airspeed and thus cannot move an aircraft from a standstill) and the ramjet
producing extra thrust at airspeeds above 1,000 km/h (600 mph). To reduce risks
in using the relatively new turbo-ramjet powerplant, the first Griffon (Nord
1500-01 Griffon I) was completed with only the 3,800 kgf thrust ATAR 101F
turbojet component.


Role
Research fighter

National origin
France

Manufacturer
Nord Aviation

First flight
20 September 1955 (Griffon I), 23 January 1957 (Griffon II)

Number built
2

First flown by Andre Turcat on 20 September 1955, the Griffon I proved to be
underpowered but plans to install the planned ramjet component were never
realised. Despite the lack of power the Griffon I still managed to reach M 1.17.
Flying with the Griffon I ceased in April 1957 in favour of the ramjet-equipped
Griffon II. Visible differences between the two aircraft were limited to the
smaller intake and two-position exhaust nozzle of the Griffon I.

After proving the aerodynamic aspects and systems of the Griffon, the 1500-01
was retired in April 1957. Flying continued with the Griffon II after its first
flight on 23 January 1957. With Major André Turcat at the controls, the Griffon
II reached a top speed of Mach 2.19 (2,330 km/h or 1,450 mph) in 1958, thus
proving the soundness of the basic design. However, the aircraft met several
technical difficulties, such as kinetic heating, due to the lack of
temperature-resistant materials, such as Inconel or titanium, in the parts of
the airframe experiencing the highest temperatures. The ramjet was found to work
well at high speed, but was unstable at medium speeds.

Production of operational versions, dubbed Super Griffon did not take place as
it was found that the requirements could be met and exceeded with less complex
and cheaper aircraft such as the Dassault Mirage III.

Specifications (Nord 1500-2 Griffon II)

General characteristics
Crew: 1
Length: 14.54 m (47 ft 8 in)
Wingspan: 8.1 m (26 ft 7 in)
Height: 5 m (16 ft 5 in)
Wing area: 32 m2 (340 sq ft)
Gross weight: 6,745 kg (14,870 lb)
Powerplant: 1 × SNECMA ATAR 101E-3 turbojet engine, 34.3 kN (7,700 lbf) thrust
Powerplant: 1 × Nord Stato-Réacteur ramjet, 68.0 kN (15,300 lbf) thrust

Performance
Maximum speed: 2,330 km/h (1,450 mph, 1,260 kn)
Maximum speed: Mach 2.19
Wing loading: 210 kg/m2 (43 lb/sq ft)



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