The Shenyang J-8’s layout with the nose air intake did not permit installation of a modern fire control radar, severely limiting the aircraft’s usefulness as an interceptor. Also, a need was perceived to enhance the fighter’s manoeuvrability – a realisation brought about by the service entry of fourth-generation fighters abroad. Hence in 1980 the No. 601 Research Institute (SARI) began exploring a radical redesign of the interceptor. Designated Shenyang J-8 fighter II, the new aircraft followed the trend set by such fighters as the McDonnell F-4 Phantom II and the MiG-23.
The J-8 fighter II was, in effect, a new aircraft, as 70% of the airframe structure and systems were reworked. The fuselage was area-ruled; the nose was occupied by an ogival radome large enough to accommodate the scanner of a powerful radar. The engines now breathed through lateral two-dimensional air intakes with boundary layer splitter plates. Speaking of which, the powerplant was also new; the J-8 fighter II was powered by two WP-13A-II turbojets rated at 4,350 kgp (9,590 Ibst) dry and 6,720 kg (14,815 Ibst) reheat.
Another change concerned the tail unit; the twin ventral fins of the J-8 gave place to a single large fin whose design was borrowed from the MiG-23 (several examples of which, as the reader remembers, had been obtained from Egypt by then). The ventral fin folded hydraulically to starboard to provide adequate ground clearance, deploying concurrently wing landing gear retraction. The number of external stores hardpoints was increased to seven by adding an extra pain inboard of the main gear units. Overall, the Shenyang J-8 fighter II bore a certain resemblance to the Sukhoi Su-15 (NATO reporting name Flagon).
The J-8 fighter II was equipped with a Type 208 pulse-Doppler fire control radar. The armament composed PL-2B, PL-5B/C/E and PL-8 IR- homing AAMs; a single Type 23-111 cannon with 200 rounds was retained.
The actual design work started in 1982 under the direction of Gu Songfeng and He Wenzhi; the development effort was quite extensive, involving 11,000 hours of wind tunnel research by the end of May 1984. The manufacturing drawings were issued to the Shenyang Aircraft Co. by May 1983 and the factory immediately began tooling up for production and manufacturing the prototypes. The first prototype (c/n J8II-01) was completed in March 1984 and made its maiden flight on 12th June, piloted by Qu Xueren; later the machine was serialled ‘840612 Black’. The development process was unbelievably short by Chinese standards, lasting a mere 17 months.
Flight tests showed that the aircraft had markedly higher performance than the J-8/J-8 I thanks to the higher thrust/weight ratio. Handing was also clearly improved, especially directional stability (poor directional stability had been one of the Finback-A’s greatest flaws). Manoeuvrability was improved only slightly because the aircraft had a G limit of 6.9. The biggest problems arose with the mission avionics, first of all the Type 208 radar, which took a long time to reach an acceptable level of performance (its detection range was only 60 km/37 miles).
In October 1988 the J-8 fighter II (also known as the J-8B) was cleared for production and service. The aircraft was operated both by the PLAAF and the PLANAF, receiving the NATO reporting name Finback-B. It was offered for export as the F-8B but found no takers.