J-8 (Jian-8 Fighter aircraft 8) / F-8
The J-8 was the first PLAAF fighter aircraft of domestic design, with design work beginning in 1964. Work on two prototypes began early in 1967 at the Shenyang Aircraft Factory (later Shenyang Aircraft Company, or SAC), the first of these flying on 5 July 1969. Development was suspended as a result of the "cultural revolution" and not resumed until 1977.
The overall configuration is a rather straightforward enlargement of the MiG-21/J-7 layout to accomodate two engines. Although it resembled Mikoyan's experimental Ye-152A, contrary to some early reports, it was not based on that aircraft. Production began in December 1979, with about 100-150 units of the first configuration entering service. Design work on the improved J-8-II began in 1980, with production beginning in the late 1980s. As with the cancelled "Super 7" upgrade to the single-engine J-7, the J-8-II completely reworked the front end of the aircraft, adding a much larger radar and ventral air inlets, along with various other less pronounced improvements. The best that can be said of the J-8 is that once upgraded it would be no more than an advanced obsolete aircraft, comparable in configuration and aerodynamic performance to the Su-15 FLAGON.
Developed by Design Institute 601 and the Shenyang Aircraft Factory, the J-8’s design of focused around five aspects: high altitude, high speed, extended range, high climb rate, and enhanced fire power. Overall, the J-8 was superior to the J-7. The J-8 could reach Mach 2.2, had a maximum ceiling of 20,000 m, a range of 2,000 km, and could climb at 200 m / s. The J-8 was armed with two cannons and two air-to-air missiles, accompanied with a more powerful radar with increased search distance. The J-8 characteristically has a nose inlet, a highly sweptback, low aspect ratio delta wings, low tail planes, and two ventral fins.
As for the powerplant of the J-8, two proposals were made. The first proposal suggested the use of a newly designed afterburning, turbofan engine. This suggestion was risky as the engine would have to be developed alongside the aircraft and could potentially be unsuccessful. The second proposal involved using improved versions of the WP7A engines. The WP7A’s performance was lower than the former, but it had already been proven before to be a proven and reliable engine. As a result, the WP7A engines were selected instead.
The J-8’s research and design peaked in the summer of 1965. The design of the aircraft was completed in 1967. In the research, the Chinese made gains in the design of aircraft flying at high mach speed, mostly in regards to the directional stability of the aircraft. J-7’s were utilized for the supersonic research, in which the data from the research served as a foundation for further J-8 development.
The improvement of the engines was previously hampered by a problem with the hollow blades of the engine. Additionally, the blades could not withstand the high temperatures needed for the turbo inlets to operate at. As a solution, newly developed superalloy, air-cooled hollow blades were utilized in the aircraft, allowing the turbo inlet temperature to be raised substantially.
The trial production of the J-8 began coincided with Great Cultural Revolution. Production of the J-8 was hampered, as factory workers were prevented from working due to the violence in 1967. Production continued at a slow pace, and few test aircraft were built. As a result, certification of the J-8 lagged as testing took 10 years, beginning in 1969. The lag was also due to the fact that much of the new technology developed for the J-8 was unproven, there was an insufficient number of test aircraft, and the team responsible for the development of the aircraft lacked experienced personnel.
The testing of the J-8 was not without obstacles. Such problems included the vibration created when the aircraft flew at transonic and supersonic speeds, which was corrected by modifying the aft fuselage’s geometry. Another problem involved the overheating of the aft fuselage at supersonic speeds, which was solved by improving the cooling valves. The test flights of the J-8 also had issues of in-flight shut down, which was remedied with the addition of a throttle retainer block and an angle of attack compensation device. The J-8 was finally certified in March 1980.Acting as China's agent, by 1987 the US Air Force had appointed Grumman prime contractor for the update, awarding it two contracts, one worth $145 million for systems definition and development, to be completed by February 1992, and one worth $100 million for program management and support, to be completed by January 1995. For $500 million China would get US avionics to update 50 F-8-IIs (plus five spare sets), to produce a fleet of beyond-visual-range interceptors. The update will introduce a new radar, headup display, mission computer, inertial navigator, air data computer, and digital databus. Kits will be supplied for installation by the Chinese. China would not be free to export the updated F-8-II, however. The US Government placed a ban on third-country technology transfer that would effectively block the export of this aircraft and its US avionics. The update went ahead, however, because China needed a capable interceptor to deter Soviet reconnaissance overflights of northern China. However, the subsequent quenching of US-Chinese relations in 1989 led to a complete cessation of cooperation in the military field.
During the 1990s two trainer programs were initiated in China -- the J-8 intermediate trainer and the JJ-7A advanced trainer. The J-8 program was hampered by US government's refusal to sell more TFE-731-2A turbofans, but problem was later solved by using indigenous (WS-11) or Ukrainian (AI-25TL) engines and J-8 finally entered series production.
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