The following is a list of variants and specifications for variants of the Chengdu J-7, which differed considerably between models in its 48-year production run. Production of the J-7 ceased after delivering 16 F-7BGIs to the Bangladesh Air Force in 2013.
Development Production of the J-7 lasted nearly half a century, beginning in November 1964 when Shenyang Aircraft Factory (SAC) started components manufacturing for aircraft, and eventually ended in May 2013. State certification of the first J-7 for series production was received on December 28, 1966, after the Cultural Revolution started. As a result of the political turmoil, early production J-7s suffered from quality issues that persisted into the 1980s, long after the end of the Cultural Revolution. More than 2,400 have been built in the many different models listed below.
Type 1962/62 series Due to the Sino-Soviet split, Soviet-built MiG-21s were not used in China, and the few that were imported beforehand were referred to as Type 1962. Designation Type 62 was subsequently used to refer to MiG-21F-13s assembled in China under license from Soviet-supplied kits. Type 1962: 12 imported MiG-21F-13 delivered and entered Chinese service by November 1962. These jets are the early production series models of MiG-21F-13 equipped with APU-28 missile launching rails (MLRs). Type 62: 15 Chinese assembled MiG-21F-13 from kits supplied by Soviet Union. The first batch of 10 was delivered in PLAAF in September 1964, followed by the remaining 5 in the 2nd batch delivered in February 1965, and all jets are the later production series models equipped with APU-13 MLRs, replacing earlier APU-28 MLRs.
J-7 series
The J-7 series was the first group of the J-7 produced. These were reverse-engineered from the MiG-21F-13 kits supplied by the USSR. However, due to the Chinese aerospace industry's inability to manufacture some of the components, the design underwent four significant changes. The initial production of J-7 was seriously affected by the political turmoil at the time, namely the Cultural Revolution, which delayed the planned production run. Due to the urgent need for the fighter, planned improvements for the early models were scaled back to allow production to begin sooner, allowing modifications to be made later when the technologies matured. J-7: First domestically built model. Fuselage was 7% stronger than MiG-21F-13 in terms of endurance to stress, achieved via more material, but this also means that the heavier J-7 was slightly less maneuverable than MiG-21F-13. J-7 was equipped with Chinese copy of SRD-5 ranging radar designated CL, short for Ce-jÜ Lei-da (测距雷达, meaning "range-finding radar" in Chinese). The range of the CL radar was only 3 km, significantly shorter than the 7 km range of the original SRD-5 on the MiG-21F-13. Production began in 1967, though only 11 J-7s were produced before production switched to improved models. F-7A: Another 12 were built and given to Albania for free as military aid. By this time, China was able to produce the APU-13 MLR of late production models of MiG-21F-13, which replaced the early APU-28 on the first 11 J-7s. The APU-13 became standard on all future J-7 variants. The completion of these last 12 J-7s marked the end of the initial production run in 1970, with a total of 23 built. After production ended, production of future models of J-7 was transferred to Chengdu Aircraft Corp (CAC) and Guizhou Aircraft Industry Corporation (GAIC). J-7 ASST: Like the original MiG-21, the J-7 also sometimes had stability problems at high altitude when traveling near Mach 2. In an attempt to avert this problem, an automatic stabilizing system was developed by Xi'an Flight Control Research Institute (also known as the 618th Institute) upon PLAAF request. A single J-7 was converted as an Automatic Stabilizing System Testbed for trials conducted between 1970 and 1971. However, the project proved to be too ambitious for the Chinese aerospace industry at the time and thus subsequently cancelled. J-7 drone: Retired J-7s were converted into aerial target drones. Subsequently, the same conversion was also carried out for later variants after they were retired. Some of these drones were destroyed by the Chengdu J-10 during weapons trials.
J-7I series
The J-7I was an improvement over the earlier J-7, with production commencing in March 1969 following the formal order placement on August 25, 1968. However, the original goal proved to be too ambitious for the Chinese aerospace industry at the time, especially during the political turmoil of the Cultural Revolution. The program only succeeded after general designer Tu Jida obtained the permission to drastically reduce the originally planned six major upgrades to merely three. J-7I: Improved J-7 with an additional gun added on the portside at the cost of 100 liters of fuel. A variable intake nosecone replaced the three-stage fixed unit on J-7 and featured a thicker intake wall. A CL-2 ranging radar with 5 km of range replaced the earlier CL radar on J-7. Production ended in 1981 after a total of 147 were delivered, including upgraded versions such as J-7A and J-7IG, but excluding export versions. In the 1960s, as soon as the PLAAF received the PL-2 air-to-air missile (AAM), J-7Is attempted to use the missiles to intercept USAF reconnaissance UAVs. However, since the PL-2's fuse was designed to target larger aircraft, these attempts were largely unsuccessful. The J-7I had more success shooting down an unknown number of USAF UAVs with guns and other air-to-air rockets. J-7I for North Korea: 40 late production version of J-7I were provided to North Korea as military aid. These can be distinguished from earlier versions of J-7I's in that the drag chute is moved to the base of the fin under the rudder, which since became the standard for all future J-7 models. J-7A: Improved J-7I with new wing pylons allowing 480 liter wing tanks to be carried under wings to make up the loss of fuel capacity that came with the new gun. J-7IG: Further improvement of J-7A. The G is for Gai (改), meaning "modified" in Chinese. The inefficient forward-hinged canopy, which was jettisoned with the ejection seat of Soviet design, was replaced by a rearward-hinged canopy jettisoned before the ejection of the new Chinese HTY-2 ejection seat. This model served as the basis for the J-7II. F-7A: Export version of J-7I for Egypt with a new engine WP-7II (涡喷-7乙, WP is short for Wo-Pen, abbreviation for Wo-Lun Pen-Qi, 涡轮喷气, meaning turbojet in Chinese), with mean time between overhaul (MBTO) increased from 100 hours to 200 hours. The CL-2 ranging radar is replaced by a more capable Type 222 radar, which is used on the J-7II. The Type 602 IFF, specially designed for export, replaced the original YD-3 IFF. The Type XU-1 low fuel warning system and Type Hang-Jia (航甲)-11-10 gun camera were both deleted. English language flight instruments replaced the Chinese instruments on the J-7. The F-7 utilized the original Soviet-type ejection system, where the forward-hinged canopy jettisoned with the ejection seat. Twenty were delivered between late 1981 and early 1982 to the Egyptian Air Force (EAF). Egypt would subsequently resell them to Iraq. J-7I reusable drone: Reusable range instrumentation drone converted from retired J-7Is to support AAM development. Development lasted from 1990 to 1998, during which time communication systems, pilot seats/ejection systems, armaments, and other systems not required for uncrewed flight were removed. Remote sensing, remote control, automatic flight control systems, and range instrumentation systems are needed to measure and record the off-distance of AAM. After repeated usage, these drones would be used as target drones, with all aircraft eventually meeting this fate. The reusable aerial range instrumentation drone was the one model in the J-7I series not designed by general designer Tu Jida.
J-7II series The J-7II series has the second-highest model count within the series. The general designer of most of the J-7II series models is also the designer of its predecessor, the J-7I, Tu Jida. J-7II: Improved J-7IG that can carry a 720-liter belly tank. Other improvements include the removal of the small window behind the canopy and the installation of a new WP-7II batch 02 engine. Thrust is increased from 39 kN to 42 kN (57.5 kN to 61 kN with afterburner), while fuel consumption is reduced by 2%, and service life of the engine is increased to 300 hours. However, the temperature of exhaust is also increased from 700 to 800 °C, accordingly when in operation the engine temperature is also increased by 100 °C. This fact was gravely overlooked, eventually causing problems to occur half a decade after J-7II production had finished, resulting in the grounding of all J-7IIs equipped with the same engine. When production ceased in 1986, a total of 375 J-7IIs were built. J-7B: Renamed J-7II. In June 1991, PLAAF discovered burnt or melted heat isolation pads in the pressure accumulator compartment in the rear section of the fuselage of J-7IIs stemming from high temperatures, due to which all J-7IIs were grounded. CAC spent half a year investigating and discovered over two dozen components that were affected by the increased temperatures of the new engine, and that these components were operating outside the temperature range for which they were originally designed. The fuselage was subsequently redesigned to fix the problem. This was begun in January 1992, but it took until May of the same year to rebuild all J-7IIs in PLAAF and PLANAF service. Lessons learned were also adopted for all subsequent production of J-7s after January 1992. The completion of the J-7B marked the final satisfactory closure of the upgrade program originally started more than a decade and half ago with J-7I during the Cultural Revolution, which lasted around a decade after its conclusion. F-7IIC: J-7II export version for Egypt. The C stands for Chu-Kou-Xing (出口型, "export version" in Chinese). Other improvements over the F-7A included being capable of carrying a 720-liter belly tank, and wing pylons rewired for French R.550 Magic AAM. The inefficient forward-hinged canopy jettisoned with the ejection seat of the Soviet design was replaced by a rearward-hinged canopy jettisoned before the ejection of a domestic Chinese design. To avoid confusion with a later model also designated F-7C, some Chinese documents also use the designation F-7W, with W standing for Wai-Mao-Xing (外贸型, "foreign trade version" in Chinese), but this designation was not used internally in CAC/GAIC. By the end of 1982, 40 were delivered to the EAF. A further 15 were later delivered to the USAF as aggressors to simulate MiG-21s. 4 were also given to Zimbabwe as military aid, and Pakistani pilots initially piloted them.