J-7B/J-7II (Fishcan) Chinese Fighter Aircraft

J-7B: Renamed J-7II. In Jun 1991, PLAAF discovered heat isolation pads in the pressure accumulator compartment in the rear section of the fuselage of J-7IIs were burnt or melted due to high temperature, so all J-7IIs were grounded. CAC spent half a year to investigate and discovered over two dozen components were affected by the increased temperature of the new engine, and these components were operating outside the temperature range they were originally designed for. Fuselage was subsequently redesigned/reworked/repaired to fix the problem, and rework/repair lasted from January thru May 1992 to fix all J-7IIs in PLAAF and PLANAF. Experience gained was also adopted for all future productions of J-7s after January 1992, and the problem never occurred again afterward. The completion of J-7B marked the final satisfactory closure of the upgrade program originally started more than a decade and half ago with J-7I during Cultural Revolution, which lasted around a decade after the end of Cultural Revolution. The Chengdu J-7 (Chinese: 歼-7; third generation export version F-7; NATO reporting name: Fishcan is a People's Republic of China license-built version of the Soviet Mikoyan-Gurevich MiG-21. Though production ceased in 2013, it continues to serve, mostly as an interceptor, in several air forces, including the People's Liberation Army Air Force. In the 1950s and early 1960s, the Soviet Union shared most of its conventional weapons technology with the People's Republic of China. The famous MiG-21, powered by a single engine and designed on a simple airframe, was inexpensive but fast, suiting the strategy of forming large groups of 'people's fighters' to overcome the technological advantages of Western aircraft. However, the Sino-Soviet split abruptly ended the initial cooperation, and from July 28 to September 1, 1960, the Soviet Union withdrew its advisers from China, resulting in the project being stopped in China. Soviet Premier Nikita Khrushchev unexpectedly wrote to Mao Zedong in February, 1962, to inform Mao that the Soviet Union was willing to transfer MiG-21 technology to China, and he asked the Chinese to send their representatives to the Soviet Union as soon as possible to discuss the details. The Chinese viewed this offer as a Soviet gesture to make peace, and they were understandably suspicious, but they were nonetheless eager to take up the Soviet offer for an aircraft deal. A delegation headed by General Liu Yalou, the commander-in-chief of the People's Liberation Army Air Force (PLAAF) and himself a Soviet military academy graduate, was dispatched to Moscow immediately, and the Chinese delegation was given three days to visit the production facility of the MiG-21, which was previously off-limits to foreigners. The authorization for this visit was personally given by Nikita Khrushchev, and on March 30, 1962, the technology transfer deal was signed. However, given the political situation and the relationship between the two countries, the Chinese were not optimistic about gaining the technology, and thus they were prepared for reverse engineering. Russian sources state that several complete examples of the MiG-21 were sent to China, flown by Soviet pilots, and China also received MiG-21Fs in kits, along with parts and technical documents. Just as the Chinese had expected, however, when the Soviets delivered the kits, parts and documents to Shenyang Aircraft Factory five months after the deal was signed, the Chinese discovered that the technical documents provided by the Soviets were incomplete and that some of the parts could not be used. China set about to reverse-engineer the aircraft for local production, and in doing so, they succeeded in solving 249 major problems and reproducing eight major technical documents that were not provided by the Soviet Union. One of the major flaws was with the Hydraulics systems, which grounded up to 70% of aircraft in some squadrons until the systems were upgraded. Another major upgrade was modifications to the fuel storage to make the aircraft more stable. The MiG-21 carries most of its fuel in the forward fuselage, causing the center of gravity to shift and become unstable after about 45 minutes of operation. The J-7 has redesigned fuel tanks and significantly larger drop tanks in order to maintain a more stable center of gravity, and therefore better Longitudinal static stability. The cockpit was also revised to replace the Soviet ejection seat, which was found to be unacceptable. The forward opening canopy was replaced by a standard canopy hinged to the rear and jettisoned before the seat ejected. Otherwise, the re-engineering effort was largely successful, as the Chinese-built J-7 aircraft showed only minor differences in design and performance from the original Soviet MiG-21. In March 1964, Shenyang Aircraft Factory began the first domestic production of the J-7 jet fighter, which they successfully accomplished the next year. However, the mass production of the J-7 aircraft was severely hindered by an unexpected social and economic problem—the Cultural Revolution—that resulted in poor initial quality and slow progress, which, in turn, resulted in full-scale production only coming about in the 1980s, by which time the original aircraft design was showing its age. In 1987 the J-7E was released, having a greatly improved wing, among other improvements. It was roughly 45% more maneuverable, and its takeoff and landing performance was greatly increased. It was also equipped with a helmet mounted sight, as well as being the first MiG-21 to be equipped with HOTAS and a multipurpose display. Many of the electronic components were British in origin, such as the gun sight and the multi purpose display. The aircraft is capable of using PL-8/Python 3 missiles with both the helmet mounted sight or the radar fire control, but the two are not connected. The pilot may use only one system at a time. In the mid 1980s Pakistan requested an aircraft with greater radar capabilities. Both the standard radar and the British Marconi radar were plagued by ground clutter, but China did not have any experience with air to ground radar at the time. In 1984 Pakistan provided assistance by having their American trained F-16 pilots provide training on proper operation of ground attack radar, which enabled the Chinese to develop the J-7M. In the late 1980s the J-7MP and J-7PG introduced significant upgrades to the radar system by converting to an Italian FAIR Grifo-7 radar. This more than tripled the effective range of the radar, as well as greatly increased the angle which the radar could detect target. The J-7 only reached its Soviet-designed capabilities in the mid 1980s. However, the fighter is affordable and has been widely exported as the F-7, often with Western systems incorporated, like the ones sold to Pakistan. There are over 20 different export variants of the J-7, some of which are equipped to use European weaponry, such as French R.550 Magic missiles. The Discovery Channel's Wings Over The Red Star series claims that the Chinese intercepted several Soviet MiG-21s en route to North Vietnam (during the Vietnam War), but these aircraft did not perform in a manner consistent with their original specifications, suggesting that the Chinese actually intercepted down-rated aircraft that were intended for export, rather than fully capable production aircraft. For this reason, the Chinese had to re-engineer the intercepted MiG-21 airframes in order to achieve their original capabilities. China later developed the Shenyang J-8 based both on the expertise gained by the program, and by utilizing the incomplete technical information acquired from the Soviet Ye-152 developmental jet. In May 2013, J-7 production has ceased after decades of manufacturing. The last 12 F-7BGIs were delivered to the Bangladesh Air Force.