After the J-6 was put into mass production and delivered to the military services, another supersonic fighter, the J-7 with M 2.0 maximum speed was manufactured based on the Soviet MiG-21. The Chinese began development of the J-7, based on incomplete technical data of the Soviet MiG-21F, in the 1960s. License production of the J-7 was carried out by the Shenyang Aircraft Factory starting in 1964. The J-7 design consisted of a delta wing and an all- movable horizontal tail surface. The J-7 could reach Mach 2.05, had a service ceiling17,500 m, and a maximum range1,530 km. The J-7 incomparison to the J-7 was comparatively easier to control, had a faster climb-rate, and had performed better in transonic and supersonic situations.