The SNCASO SO.9000 Trident was a French mixed-power interceptor aircraft built by aircraft manufacturer SNCASO during the 1950s. As part of a wider effort to re-build French military power during the late 1940s and to furnish France with advanced, new domestically produced designs, a request for a supersonic-capable point-defence interceptor aircraft to equip the French Air Force was issued to SNCASO. In response, the firm designed the mixed-propulsion Trident, powered by a single SEPR rocket engine, which was augmented by wingtip-mounted turbojet engines, and the Air Force ordered two prototypes.
The two SO.9000 Trident Is demonstrated the feasibility of the design concept despite the loss of one aircraft during flight testing and the Air Force ordered a batch of three prototype SO.9050 Trident II fighters in 1954, and a batch of six pre-production aircraft in 1956 to further develop the aircraft so it could serve as a short-range interceptor. Only six of these nine aircraft were ultimately completed, of which all three prototypes were damaged or destroyed in accidents before the programme was cancelled in 1958 despite their record-setting performance.
