The J-8 originated from a PLA requirement for a fighter with performance and combat capability superior to that of the MiG-21. Shenyang's decision to use twin engines, and the company's long association with the 'tailed delta' MiG-21-type configuration, ensured that the new aircraft looked like a scaled-up MiG-21; as such, it bore an astonishing resemblance to Mikoyan's Ye-152A 'Flipper'. The requirement was proposed in 1964, and development was in full swing by 1965. The two prototypes were completed in July 1968, at the height of the Cultural Revolution but, remarkably, the flight test programme went ahead, albeit at a slow pace. The first J-8 made its maiden flight on 5 July 1969, and certification followed 10 years later. Engine shutdowns, high temperatures in the rear fuselage and transonic vibration were the only problems. These were quickly solved, and the 10-year gap before certification was almost entirely due to political interference and disruption to the factory by the repression of many of its key workers.
The original J-8 had a small ranging radar in the intake centrebody, and retained the single-piece forward-hinging canopy of the original J-7. The aircraft was armed with a single 30-mm cannon and up to four underwing PL-2 air-to-air missiles. Any production was very limited.
The J-8I was designed as an all-weather fighter derivative of the basic J-8, and featured a new Type 204 Sichuan SR-4 radar in an enlarged intake centrebody. The 30-mm cannon was replaced by a twin-barrelled 23-mm 23-III cannon, and provision was made for four rocket pods as an optional alternative to the PL-2 missiles. The J-8I retained the same 59-kN (13,450-lb st) WP-7B engines as the basic J-8 (also used in the Chengdu F-7M) but introduced some aerodynamic refinements, with small fences above the wing, revised wingtips and relocated airbrakes. The aircraft also introduced a two-piece canopy, with an upward-hinging rear transparency and a fixed windscreen. This marked the replacement of the highly unpopular Type I ejection seat with the Type II, which was more reliable and which could be used at ground level at speeds in excess of 140 kt (160 mph; 259 km/h). Prototype assembly was completed in May 1980, but the aircraft burned out during its first engine run after a fuel or hydraulic pipe fractured due to resonance. The second prototype was hurriedly completed and made the type's maiden flight on 24 April 1981. Certification was granted in July 1985. J-8 and J-8I production totalled about 100 aircraft, and some of the original J-8s are said to have been converted to the later standard.
Although the J-8I marked a great improvement over the original 'Finback', there was clearly scope for a more radical redesign. This led to the development of the J-8II 'Finback-B', which was given the go-ahead in May 1981. The new variant had relocated lateral air intakes to feed its 69-kN (15,430-lb st) WP-13B turbojets, leaving the nose free for a radar antenna of the largest possible diameter. The engine intakes bear a striking similarity to those of the MiG-23 Flogger, which should come as no surprise, since some of Egypt's MiG-23s were shipped to China in exchange for J-7 deliveries. The original aircraft's twin ventral strakes were replaced by a MiG-23-style folding fin. Seventy per cent of the airframe was changed by comparison with the original J-8, as were 30 per cent of the contractor-supplied parts.
The operational requirement for the new variant was approved in September 1980. The extensive use of CAD/CAM reduced design and development time to the minimum, the first of four prototypes flying on 12 June 1984. There has been small-scale batch production of the J-8II, but the type may not have entered service. An export version, designated F-8B, is powered by a pair of WP-13B turbojets and introduces a pulse-Doppler look-down radar and digital avionics, with a HUD and two HDDs.
On 5 August 1987 Grumman received a $501.8 million contract to design, develop and test an avionics upgrade for the J-8II under the Foreign Military Sales Program. Sponsored by the USAF's Aeronautical Systems Division, the contract covered installation of the new avionics package in two J-8II airframes supplied by China, and the provision of 50 shipsets for local installation, with development to be completed by February 1991 and delivery of the modification kits to be completed by January 1995. The new avionics package included a modified Westinghouse AN/APG-66 radar, with a constant wave illuminator to give compatibility with semi-active radar homing missiles like the AIM-7 Sparrow. The aircraft would also receive a modern HUD, a US ejection seat and a Litton LN39 INS, plus a bubble canopy and frameless wraparound windscreen. The massacre in Tiananmen Square in June 1989 led to an immediate halt on work on the project, and the expulsion of many of the Chinese engineers.
Development restarted, but flight test and kit delivery would have required a change in State Department policy; with deliveries unlikely, China pulled out of the project, leading to its cancellation. The cancellation of the Peace Pearl upgrade may have killed off the J-8. The PLAAF has taken delivery of Su-27 Flankers, and seems more likely to purchase further examples, and perhaps MiG-29s, than to procure an indigenous alternative lacking sophisticated modern avionics and which represents an 'F-4-generation' aircraft.

Nation of Orgin: China
Consructor: Shenyang Aircraft
Type: Interceptor
Crew: One
Length 70 ft 10 in / 21.6 m
Height 17 ft 9 in / 5.4 m
Wing Span 30 ft in / 9.3 m
Max t-o weight: 39,200 lb / 17,800 kg
Engine: two Liyang Wopen-7B afterburning turbojets rated 14,815 lbst each
Maximum speed: 1,450 mph / 2,340 km/h / Mach 2.2
Range: 700 nm
Ceiling: 20200 m (66,275 ft)
Armament: 2 23mm Cannon; 7 hardpoints for PL-2 AAM, PL-7 AAM, bombs, rockets and drop tanks