www.China-Defense.com

J-7M: After Deng's reform and opening-up policies, China was able to acquire more sophisticated technologies from the West and thus could improve earlier designs. In order to boost its export prospects, the Chengdu Aircraft Factory used an English Marconi fire control system to improve the J-7-II design. After the upgrade it was known as the J-7M and featured an increased payload, additional underwing pylons, a head-up-display, a Martin Baker zero-zero ejection seat and strengthened structure. The J-7M was successfully test flown in 1984 and exported to Pakistan and other developing countries.

J-7-III: A major modification to the original J-7 design featuring a new fuselage, an enlarged dorsal fuel tank, an all-weather radar, engine thrust increased from 6,100kg to 6,600kg, enhanced range and speed performance. The design stressed all-weather operational capability, improved low altitude flight performance and air-to-ground strike capability over a decent range - all weaknesses in existing PLAAF fighters exposed in the 1979 conflict with Vietnam. After successful test flights in 1984 the J-7-III began to equip PLAAF units in small numbers. Most sources suggest the J-7-III was not entirely successful being too heavy and losing agility compared to other J-7 variants. Casual observers may mistake the J-7-III for a Russian MiG-21MF (possibly because the J-7-III was derived from a MiG-21MF obtained from Egypt).

J-8-II: A significant improvement over the original J-8-I, the key design breakthrough was moving away from the nose intake to fuselage side intakes, allowing room for a large radar antenna in the nose. The Type-208 radar is reportedly look-down capable and can guide semi-active radar homing AAMs. The J-8-II is powered by two WP-13-II turbojets (each 6600kg thrust) giving it improved low altitude performance and good air-to-ground load carrying ability. Development began in 1980. A prototype successfully flew in 1984, the design was finalised in 1988 and the J-8-II entered PLANAF service in 1992. Despite a long gestation, successful development of the J-8-II was an important milestone for the Chinese aviation industry.