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Published: 2010-10-28 05:15:21 +0000 UTC; Views: 19322; Favourites: 93; Downloads: 1083
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Description
The J-7 (Jian-7, or F-7 in its export name) is a Chinese copy of the Russian Mikoyan-Gurevich MiG-21 (NATO codename: Fishbed) supersonic jet fighter aircraft. Over 1,000 examples in different variants have been built by three aircraft manufacturers in Shenyang, Chengdu, and Guizhou since the production first began in the late 1970s. As well as serving with the PLA, the J-7 was also exported to Albania, Bangladesh, Burma, Egypt, Iran, Iraq, North Korea, Pakistan, Sri Lanka, Sudan, Tanzania, and Zimbabwe. The J-7 is still in production today and serves in the air forces of several countries, mostly as an interceptor fighter.The MiG-21/J-7 was designed as an interceptor fighter with secondary capability for ground attack. The aircraft’s simple controls, engine, weapons, and avionics were typical of Soviet-era military designs. The fighter has a small sized airframe with a rugged and powerful engine inside. With its delta wings the aircraft has an excellent fast-climbing performance, but any form of turning combat would led to rapid loss of speed. The pilot is buried deeply in the cockpit and has a poor cockpit visibility. The aircraft has a short range, and can only take IR-homing short-range air-to-air missiles for visual range combat, making it only suitable for point air defence.
In March 1961, the People’s Republic of China (PRC) and the Soviet Union signed the official agreement of a technology transfer package, which allowed China to build the MiG-21F-13 Fishbed-C) fighter, the Tumansky R-11F-300 turbojet engine, and the K-13 (NATO codename: AA-2 Atoll) air-to-air missile (AAM) locally under license. The production of the MiG-21 was carried out by Shenyang Aircraft Plant (now Shenyang Aircraft Corporation, SAC), while Shenyang Aero Engine Factory (now Shenyang Liming Aero Engine Company) was responsible for the production of the R-11F-300 turbojet engine.
Shenyang received few MiG-21 examples as well as some kits for assembly from the Soviet Union. However, the delivery of the technical documents was not completed due to the rapidly deteriorating relation between Beijing and Moscow. As a result, Shenyang had to build the MiG-21 by reverse-engineering. A significant amount of survey and testing on the aircraft was carried out. Although this process has caused some delay in the development programme, it enabled the Chinese engineers to fully understand the aircraft design, making it possible for future modifications and improvements.
The Chinese copy of the MiG-21 was originally named Type 62 and this was later changed to Jian-7 (J-7) in line with the PLAAF’s fighter aircraft designations. A successful static test of the J-7 was carried out in November 1965. The first J-7 (serial number ‘0002’) with 100% Chinese-made content made its maiden flight in January 1966. The Chinese copy of the Tumansky R-11F-300 turbojet engine, known as WP-7, was successfully tested in October 1965. The engine was certified for production in December 1966. The J-7 fighter was certified for production finalisation in June 1967.
Between 1966 and 1968, PLAAF J-7 fighters shot down six U.S.-made high-altitude unmanned aerial vehicles (UAV) over the Chinese territory. These scores were achieved with the aircraft 30mm cannon and unguided air-to-air rockets. The PLAAF J-7s also made several attempts to shoot the USAF unmanned reconnaissance aerial vehicles over the China mainland with their PL-2 (K-13/AA-2 copy) AAM but none was successful.
J-7I
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J-7I (Chinese Internet)
In the mid-1960s, the Chinese government ordered that the J-7 development and production facilities to be relocate to the remote southwest region. The J-7 production was reassigned to the newly built Chengdu Aircraft Manufacturing Plant (now Chengdu Aircraft Industry Corporation, CAC) in Sichuan Province. The WP-7 turbojet production was also handed over to Liyang Aerial Engine Company in Guizhou Province in 1968.
Chengdu modified the J-7 design from 1969 to 1975. The resulted J-7I variant was introduced in June 1976. The J-7I development was severely disrupted by the ‘Culture Revolution’. By the time this variant entered service, the J-7 fighter design had already become obsolete. Additionally, the J-7I suffered from some serious design flaws and was built in poor quality. As a result, the fighter only saw limited service with the PLA. The J-7I variant was entirely retired from active service in the early 1990s, with some examples converted into unmanned supersonic target drones.
The J-7I differed to the original J-7 design by adding a second cannon inside the left wing-root, and replacing the original three-position nose inlet centre-body with a fully translating design. The aircraft carries two indigenous PL-2 (K-13/AA-2 copy) IR-homing short-range AAM under the wings.
Some of the retired J-7I fighters have been converted by the PLAAF into unmanned target drones for weapon tests and training roles. The pilot seat on these aircraft has been removed and replaced by radio control equipment. The J-7 target drone can fly at supersonic speed and simulate typical manoeuvres of modern combat aircraft.
F-7A
The F-7A is the export variant of the J-7I. It is powered by an improved 58.8kN thrust WP-7B turbojet engine replacing the original 56.39kN thrust WP-7. The engine also featured an increased overhaul time. The break chute was relocated at base of rudder to improve the landing performance and shorten run. This variant was supplied to Albania and Tanzania in the 1970s.
J-7II
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J-7II (Chinese Internet)
As the J-7I could not meet the PLA requirements, in the late 1970s Chengdu introduced a further improved variant J-7II, which eventually became the first variant of the J-7 series to have been built in significant numbers.
The J-7II features four important improvements:
First, the aircraft had its ejection escape system replaced. The ejection seat on the J-7 and J-7I was a direct copy of the Soviet-design on the MiG-21F-13. The system had the canopy automatically engaged to the seat at the beginning of the ejection and was then separated after the ejection. The system was highly unreliable and had claimed several lives of PLAAF pilots. The J-7II had the old escape system replaced by an indigenous open ejection escape system, which featured a new HTY-2 rocket ejection seat with better safety and reliability records. Over 300 ejection tests both on the ground and air demonstrated improved ejection capabilities at zero altitude and low-speed conditions (250~850km/h). The new rocket ejection system worked successively in six real ejections in 1985.
To fit the new ejection seat, the original front-hinged one-piece cockpit canopy replaced by a fixed three-piece front windscreen and a rear-hinged canopy.
The second improvement involved the replacement of the original WP-7 engine with an improved WP-7B, which had increased thrust (12.8% higher thrust and 70% higher afterburner thrust) and an average overhaul time of 200 hours.
The third improvement was a 720 litre centreline drop tank replacing the previous 480 litre for increased fuel capacity and extended range.
Finally, the drag chute bay was modified to deploy the drag chute at a higher landing speed for shorter landing distance. The aircraft was able to deploy its drag chute less than one meter above ground, reducing the landing distance to less than 800m.
The J-7II first flew in December 1978 and was certified for design finalisation in September 1979. It is one of the most popular variants in the J-7 series.
F-7B
The F-7B was the export version of the J-7II. The aircraft made its first flight on 16 May 1982. This variant is capable of carrying two Chinese indigenous PL-2 French Magic R.550 short-range AAMs under the wings. The F-7B also features a further improved ejection seat and better cockpit avionics. 90 examples were exported to Iraq and 22 examples to Sudan in the 1980s.
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J-7IIA (Chinese Internet)
J-7IIA
The improved J-7IIA first flew on 7 March 1984. This variant is generally similar to the J-7II, but with improved avionics based on Western technologies. The nose probe was relocated from beneath intake to top lip of intake, offset to starboard.
J-7IIH
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J-7IIH (Chinese Internet)
The J-7IIH (later renamed J-7H) was the later production variant of the J-7II. First flying in March 1985, the aircraft was fitted with new utility pylons that can carry both air-to-air missiles (AAM) and free-fall bombs. The pylons were rewired to fire the indigenous PL-8 IR-homing short-range AAM. Other improvement included enhanced landing gear and improved powerplant with extended service life.
F-7M Airguard (F-7MP)
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F-7M Skyguard (Chinese Internet)
During the honeymoon period of the China-Western relations in the early 1980s, the Chinese Ministry of Aeronautics (MoA) decided to import 100 sets of the British GEC-Marconi avionics to upgrade the existing PLAAF J-7II fleet. Chengdu Aircraft Manufactory Factory was responsible for the integration of the British avionics with the J-7II airframe. The project was later cancelled due to changing requirements but Chengdu continued the upgrade independently. The resulted F-7M for the export market made first flew in August 1983 and was certified in November 1984. The aircraft turned out to be a huge success in the export market, with 164 examples sold to Bangladesh, Iran, Myanmar and Zimbabwe since 1985. The improved F-7MP made its first flight on 9 June 1988.
Seven GEC-Marconi designed items were incorporated into the avionics of the F-7M, including the Type 956 HUDWAC (head-up display and weapon aiming computer), the Skyranger air-to-air ranging radar with anti-jamming capability, an air data computer, a radar altimeter, an identification of friend or foe (IFF), and secured radio communications.
The aircraft also features eight domestic improvements including the improved electrical power unit for the new avionics; two additional under-wing stores stations; improved WP-7B(BM) engine; bird-proof windscreen; strengthened landing gear; ability to carry Magic R550 and the Chinese PL-7 AAM; and nose probe relocated from beneath intake to top lip of intake, offset to starboard.
F-7P Skybolt
The F-7P Skybolt was a modified version of the F-7MP specially tailored for the Pakistani Air Force (PAF). This variant was embedded with 24 modifications to meet the specific requirements of the PAF, including the ability to carry four AIM-9 Sidewinders AAMs and fitment of the U.S. Martin-Baker Mk 10L ejection seat. Later variants F-7MP featured improved cockpit layout and navigation system incorporating Collins AN/ARN-147 VOR/ILS receiver, AN/ARN-149 ADF and Pro Line II digital DME-42. Avionics (contract for up to 100 sets delivered to China from early 1989). On later variant the original British GEC-Marconi Skyranger radar was replaced by a Italian FIAR Grifo 7 fire-control radar (range of more than 55km).
J-7C
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J-7C (Chinese Internet)
As the J-7I and J-7II both lack the capability to combat in all-weather, day/night conditions, Chengdu began to develop an improved all-weather variant in the early 1970s. The project was initially proposed in 1972, but it did not enter full-scaled development until the late 1970s. The development and production responsibilities were shared between Chengdu Aircraft Factory (now CAC) and Guizhou Aircraft Factory (also known as Base 011, now Guizhou Aviation Industries Group Co, GAIGC). Chengdu was responsible for the aircraft’s fuselage as well as flight testing. Guizhou was responsible for the aircraft’s wings and the landing gear. The aircraft received official designation J-7III (later renamed J-7C).
The J-7III variant was to be based on the Soviet MiG-21MF (NATO codename: Fishbed-J), which was the all-weather, multirole fighter version of the MiG-21 family. China obtained an example of MiG-21MF from Egypt in February 1979. The aircraft was then handed to Chengdu for reverse-engineering. The development began in May 1979 and was completed by May 1980. J-7III was the first Chinese-made aircraft to have used computer aided design (CAD) and system engineering management in its development. Static testing of the airframe was completed in April 1984, and the aircraft made its first flight on 26 April 1984.
Despite sharing the same designation with previous J-7 models, the J-7III was largely a new design, with 80% of its parts being newly developed. The aircraft is generally similar to MiG-21MF in aerodynamic design, though its avionics, armaments, and powerplant were all indigenous designs.
J-7III was the first Chinese-made fighter to be fitted sophisticated avionics suite for all-weather operations. The enlarged nose inlet cone accommodated a JL-7 multi-purpose pulse Doppler (PD) fire-control radar, which had a maximum detecting range of 30km against airborne targets. Based on integrated circuit technology, the JL-7 radar could work in air-to-air or air-to-ground mode. In air-to-air mode its functions included air target search, manual target acquisition, identification of friend or foe, target tracking using optical gun sight or head-up display (HUD), tail attack. In air-to-ground mode the radar could perform rangefinding and ground attack using optical sight.
The aircraft was originally fitted with a SM-8 (HK-03D) optical sight, but this was replaced by a HK-13A head-up display (HUD). Other avionics included KJ-11 autopilot, ADS-1 air data computer, WL-7 radio compass, 264A radio altimeter, XS-6A beacon marker receiver, Type 481 data transmission/navigation system, Type 506 HF radio, Type 605A IFF, Type 930-II radar warning receiver (RWR), and GT-1 and chaff/flare dispenser.
The aircraft was powered by an improved WP-13 turbojet developed by Guizhou Liyang Aero Engine Company. The engine was rated at 4,100kg dry and 6,600kg with afterburning. Like MiG-21MF, J-7III had an enlarged dorsal spine to accommodate additional fuel. As a result, the aircraft had its cockpit canopy redesigned with a fixed three-piece windscreen and a (right) side-hinged canopy. The enlarged dorsal spine further reduced the aircraft’s already poor cockpit visibility. Therefore the pilot had to rely completely on a single canopy mirror for rear vision. The aircraft's escape system had a HTY-4 rocket ejection seat.
J-7III carried four PL-2 or PL-5 IR-homing, short-range air-to-air missiles under the wing stations. The centreline fuselage station is pumped to carry a 480 litre or 760 litre drop tank. Alternatively it could be used to carry integrated bomb pylon, navigation pod, targeting pod, reconnaissance pod, or EW/ECM pod. For air-to-ground attack the aircraft carried 57mm, 90mm or 130mm rocket launcher pods under the wing stations. Fixed weapon included a Type 23-III 23mm twin-barrel cannon with 200 rounds.
Despite PLAAF’s high hope in the J-7III fighter, the aircraft later proved trouble prone. The JL-7 fire-control radar was unreliable and lacked features such as ‘beyond-visual-range’ (BVR) combat and ‘look-down, shoot-down’ which were commonly found on Western and Russian fighters introduced in the same age. The modification in the airframe design also increased the aircraft’s external profile and overall weight considerably, resulting in degraded manoeuvrability. The fighter only saw limited service (20~30 examples) with PLAAF under the designation J-7C. Painted in the special camouflage colour scheme, these J-7Cs were used as dedicated night fighters in PLAAF 15th Air Division based at Zhangjiakou, Hebei Province.
J-7D
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J-7D (Chinese Internet)
In response to J-7C’s weaknesses, Chengdu and Guizhou introduced the improved J-7D (originally named J-7IIIA or J-7IV) in the early 1990s. The improvements focused on the avionics, including the JL-7A fire-control radar, HK-13A HUD, JD-3II tactical aircraft navigation (TACAN) system, Type 563B inertial navigation system (INS), KJ-8602 radar warning receiver, and TKR-122 VHF radio. The powerplant was replaced by an improved WP-13F1 turbojet with increased thrust. The J-7D fighter was capable of firing the more advanced PL-7 and PL-8 short-range AAM, but still lacked the BVR combat capability.
Development of J-7D began in 1988, and the aircraft first flew on 20 August 1991. The production was approved in November 1994 and the fighter achieved initial operation capability with PLAAF in 1995. By then the PLAAF had already decided to allocate its resources to more capable fighters such as Su-27/30 and J-8B. As a result only 20~30 examples of the J-7D were built before the production finally stopped in 1999.
Unlike other members of the J-7 family, the J-7C and J-7D have not been offered to the export market.
J-7E
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J-7E (Chinese Internet)
The J-7E was the third-generation derivative of the Chengdu Aircraft Industrial Corporation (CAC) J-7 family. First introduced in the early 1990s, the aircraft was based on the airframe of the J-7II, but with redesigned wings and upgraded avionics. The fighter was also prompted to the international market under the designation F-7MG, and is serving with the Pakistani Air Force (PAF) under the designation F-7PG. The J-7E production began in the early 1990s and stopped in 2002. A further improved domestic variant designated J-7G was introduced in 2002.
As Chengdu’s attempt to reverse engineer the MiG-21MF Fishbed-J all-weather fighter was not entirely successful, the company went back to the J-7II (MiG-21F-13 Fishbed-C) design in the late 1980s to develop an improved variant J-7E for the PLA. The J-7E first flew in May 1990 and the flight testing had been completed by 1992. The J-7E began to serve with the PLA Air Force (PLAAF) and PLA Naval Air Force (PLANAF) in 1995. The export variant F-7MG upgraded with Western avionics was first revealed during the 1996 Zhuhai Air Show.
A significant amount of new technologies has been adopted in the J-7E/F-7MG’s development and production, including computer aided design and manufacturing (CAD/CAM), numerical control processing, laser/electromagnetic tests, composite materials, and water jet cutting. These technologies enabled the 1950s-era design to be built in the 1990s quality standards, thus improving the aircraft’s performance and capabilities.
Improvements on the J-7E mainly focused on aerodynamic performance and avionics. The original delta wing plan-form was with a new “double-delta” design similar to that of the Russian Su-15 and Swedish Saab J-35 Draken. The new wings retain the existing leading-edge sweep angle of 57° inboard but have reduced sweep angle of 42° on the outboard wing, which also has a leading-edge flap fitted. This design offered an excellent solution to the inherent low aspect ratio problem of a slender delta. The slighting larger wingspan and 8.17% more wing area also gave an increased internal fuel capacity (from 2,080kg to 4,165kg) and much enhanced manoeuvrability.
The aircraft’s performance was further enhanced by the introduction of an improved Liming (LMC) Wopen-13F turbojet rated at 44.1kN dry and 66.7kN with afterburning, giving a thrust-to-weight ratio of about 0.9 in clean, take-off configuration compared with 0.8 of J-7B. The sea-level climbing rate has increased from 155m/s to 195m/s; the ferry range has increased from 1,500km to 2,200km; the G limit has increased from 7g to 8g. The maximum instantaneous turn rate of the J-7E is 25.2 degree/sec, and the maximum sustained turn rate at 1,000m altitude is 16 degree/sec. According to CAC’s advertisement, compared with the J-7B, the overall aerodynamic performance of J-7E has increased by 43%, and the combat effectiveness has increased by 84%.
Avionics suite of the aircraft includes the Type 226 ranging radar, JT-1 head-up display (HUD), KW8602 radar warning receiver (RWR), Type 8430 air data computer, JD-3 tactical aircraft navigation (TACAN), KG-8605 internal radar noise jammer, and Type 941-4AC chaff/flare dispenser.
Fixed weapon includes one 30mm Type 30-1 cannon with 60 rounds fitted in lower starboard side of the fuselage. Four under-wing stores stations can carry up to 2,000kg of disposable stores (each unit rated at 500kg), typical weapons are PL-5 or PL-8 short-range AAMs, free-fall weapons such as 500, 250, 100 and 50kg bombs, and multiple rocket launcher pods each carrying twelve 55mm or seven 90mm unguided rockets. Centre fuselage station and two outboard wing stations are pumped to carry 720 litre drop tanks.
F-7MG
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F-7MG (Chinese Internet)
The F-7MG is an export fighter aircraft developed by Chengdu Aircraft Corporation (CAC) based on the J-7E. The project was jointly funded by CAC, Shenyang Liming Aero Engine Group (LMC), and China Aviation Technology Import and Export Corporation (CATIC). Liming was also responsible for the development and production of the improved WP-13F turbojet engine, while CATIC was responsible for the marketing of the aircraft.
The F-7MG was based on the J-7E airframe, but upgraded with Western avionics. The fighter was fitted with an X-band British Marconi Electronic Systems Super Sky Ranger pulse-Doppler fire-control radar. The Super Skyranger was an improved variant of the Skyranger radar used on the F-7M fighter. It has the ‘look-down/shoot-down’ capability and five working modes. The radar can track up to 8 targets simultaneously while attacking one of them.
Marconi head-up display (HUD) and fire-control computer are fitted as standard. The HOTAS (hands on throttle-and-stick) cockpit design allows the pilot to fly the aircraft without taking his eyes off the horizon and HUD, thus improving his situational awareness. If necessary, the fighter can also be integrated with a helmet-mounted display (HMS). The fighter has been added with a second 30mm Type 30-I cannon carrying 60 rounds fitted in the lower port side of the fuselage.
Other avionics include a stores management system, which helps the pilot to establish the status of stores including configuration, fusing, and weapon codes. A voice warning system, colour video recorder, elaborating cockpit lighting are also among the improvements. The colour electronic flight control system (EFCS) includes two displays, one for the altitude and the other for the heading and navigation sub-systems, such as Automatic Direction Finding (ADF), VHF Omni-directional Range (VOR), Tactical Aid to Navigation (TACAN), and Instrument Landing System (ILS), etc.
F-7PG
The F-7MG fighter is serving with the Pakistani Air Force (PAF) as the F-7PG. The PG variant is generally same as the MG variant but its avionic configuration has been tailored to meet the PAF requirements. As the Marconi Super Skyranger radar did not meet the PAF requirements, the F-7PG is fitted with an I-band Italian FIAR Grifo-7 pulse-Doppler fire-control radar (37km range), which was optimised to fire the U.S.-made AIM-9L all-aspect short-range AAM, making a lethal combination in air-to-air combat.
The PAK pilots first test flew the F-7MG fighter at Chengdu’s test site in 1997. Following the flight evaluations, the PAF ordered 46 F-7PGs and nine FT-7PG. The PAF was so impressed with the aircraft’s performance that it ordered an additional 11 F-7PGs subsequently.
J-7G
With the success of F-7MG/PG series export fighter, Chengdu quickly developed its domestic equivalent J-7G with similar design upgrades. The J-7G is equipped with an I/J-band KLJ-6E Lieying (“Falcon”) pulse-Doppler fire-control radar allegedly based on the Israeli EL/M2001. A new one-piece front windscreen replaced the original three-piece design for better cockpit visibility. Other improvements include a new Type III IFF, an indigenous zero-height, zero-speed ejection seat, and improved electronic countermeasures (ECM) suite.
The J-7G firs flew in June 2002 and entered the PLAAF service in 2004. The J-7G production is expected to last for few years before the J-10 and J-11B fighter can enter service in significant numbers. 16 examples of the J-7G fighter were delivered to the PLAAF 37th Air Division (serial number 5XX8X) based at Urumqi, Xinjiang. An additional 32 aircraft were delivered to the PLAAF 12th Division (serial number 2XX3X) in November 2006. An unarmed version designated J-7GB replaced the earlier J-7EB in the PLAAF August 1st Aerobatic Demonstration Team.
J-7EB and J-7GB
The J-7EB is the unarmed variant of the J-7E specially designed for the PLAAF August 1st Aerobatic Desmontration Team. The aircraft has its two 23mm internal cannons removed and carries a smoke generator under the centre fuselage station. The aircraft has now been replaced by the J-7GB derived from the J-7G.
J-7 Export
Country
Variants
Quantity
Notes
Albania F-7A 12
Egypt F-7A 90 Delivered in the early 1980s
Tanzania F-7A 16 Delivered in the early 1980s
Iraq F-7B 90 Delivered in the mid-1980s
North Korea F-7B 40 Delivered in the early 1980s
Sri Lanka F-7BS
FT-7 4
2 Delivered in the 1990s
Sudan F-7B 22 Delivered in the 1990s
Bangladesh F-7M
FT-7
F-7BG
FT-7BG 14
2
12
4 F-7M and FT-7 delivered in 1989;
F-7BG and FT-7BG delivered in 2006
Burma F-7M 24
Iran F-7M 18 Delivered in the mid-1980s
Burma F-7M 24
Namibia F-7NG
FT-7NG 12 in total Delivered in 2006
Nigeria F-7NI
FT-7NI 12 in total Delivered in 2006
Zimbabwe F-7M
FT-7 22
2 Delivered in the late 1980s
Pakistan F-7P Skybolt
FT-7P Skybolt 80
15 F-7P and FT-7P delivered in 1988~90
Pakistan F-7PG
FT-7PG 57
9 F-7PG and FT-7PG delivered in 2001~02
Last update: 25 December 2008
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Comments: 8
arenafighter [2010-11-03 03:40:03 +0000 UTC]
Cool! might build a Model of it,If i can find one!
👍: 0 ⏩: 0
S7alker117 [2010-10-28 10:18:40 +0000 UTC]
Nice model.
This one actually has a very elegant wing, compared to the original MiG-21. I would say the chinese realy improved the fighter.
👍: 0 ⏩: 0
BlacktailFA [2010-10-28 08:25:54 +0000 UTC]
Good job on the Cranked-Delta J-7 --- I've never seen a schematic of it before!
👍: 0 ⏩: 0
Stealthflanker [2010-10-28 07:11:46 +0000 UTC]
This is so far.. in my opinion.. the most refined version of MiG-21's
👍: 1 ⏩: 0