The SNCASO Trident was a French mixed-propulsion interceptor built during the 1950s. It was powered by a single SEPR rocket engine, which was augmented by wingtip-mounted turbojet engines. This is the first of two prototype Trident I's built. Three prototypes and six pre-production Trident II were ordered and an fourth incomplete, pre-production Trident III was also produced. Only six of these nine Trident IIs 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.