The Nord 1500 Griffon was an experimental ramjet-powered interceptor aircraft designed and built by French state-owned aircraft manufacturer Nord Aviation. The Griffon was developed to become a Mach 2 follow on to the supersonic Nord Gerfaut research aircraft. Development of the aircraft began in earnest after the receipt of a letter of intent in 1953 for a pair of unarmed research aircraft.
The design featured an innovative dual propulsion turbojet-ramjet configuration; the former being used to takeoff and attain sufficient speed to start the latter.The Griffon I was flown for the first time on 20 September 1955. Initially powered by a 4100kg thrust SNECMA Atar 101G21 turbojet, it was flown later with a 3800kg thrust Atar 101F.
At the completion of initial testing the airframe was modified to accept a 3500kg thrust Atar 101E3 turbojet within the ducting of an integral ramjet of Nord design, the turbojet being located just forward of the ramjet burners.
Performance was disappointing as it failed to exceed the Mach 1.3 of the Griffon I as the ramjet was still not receiving enough air to fully power it. The Griffon II subsequently had the intake enlarged yet again and reached Mach 1.85 on its first test flight afterwards.The Griffon II set a speed record of 2,320 kilometres per hour (1,440 mph) on 5 October 1959.