China was receiving aircraft and technical help from the USSR. When Egypt and China seemed to be looking to the US for assistance, relations with the USSR ended. To keep aircraft development going in China, Egypt sent a Mig-21MF in return for a Romeo Class SSK sub. China reverse engineered the Mig-21MF and developed the J-7C/D. Externally the J-7D was almost identical but had some improved avionics and weapons controls, many J-7Ds were just upgraded J-7Cs. This J-7D originally was an operational night fighter under the Beijing MR (Military Region) at Huairen Air Field.
Work on the Chengdu J-7 111 began in 1981 with the first flight taking place in 1984 but it wasn’t until 1992 that the PLAAF began to be equipped with them. The delay was caused by the problems the development of the WP-13 engine and its certification. The Chinese Chengdu J-7 III and the Mig-27MF have an almost identical physical appearance making the shape of the parachute brake covers one of only a few visible differences. The Chengdu J-7 III also has blown flaps. There were over 2,450 J-7 variants manufactured.