J-9: The J-9 project ran in parallel with the J-8 project but used a completely new airframe. The design target maximum speed was Mach 2.4 at above 20,000 metres altitude. In order to achieve this target the J-9 was fitted with an 8,500kg thrust turbojet engine and the 601 Institute initially used a tailless delta design. Development at this point shifted to the newly built 611 Institute and the Chengdu Aircraft Factory. At the beginning of the 1970s, the 611 Institute proposed a new design using a canard ahead of the delta wing (not dissimilar to the Swedish Viggen), but because it required new materials and know-how plus engine performance problems it wasn't until 1975 before the design could be completed. The new J-9 design was quite advanced with air intakes on the fuselage sides featuring variable inlet geometry to alter the compression mixture. It used a 12,400 kg wet thrust turbofan engine and featured a Type 205 radar (search range about 70km) and four PL-4 radar-guided air-to-air missiles. The J-9 plan was discontinued in 1980. However, the effort was not totally wasted as the J-9 development enabled Chinese engineers to gain experience with the canard layout type, experience that would prove useful in the J-10 project.
Source: china-defense.com
