In the 1960s, the United States and the Kuomintang of Taiwan Province Province used manned and unmanned high-altitude reconnaissance planes such as U-2 and Firebee, taking Taiwan Province Province and Thailand as frontier bases, and frequently conducted reconnaissance activities in Chinese mainland. All the planes installed by our army at that time could not meet the needs of catching the enemy at high altitude, so it was urgent to develop a high-altitude and high-speed interceptor, which was the origin of J-8. At this time, after successfully copying MIG-17 and MIG-19, China turned its attention to the advanced MIG -2 1. Due to the breakdown of Sino-Soviet relations, the drawings obtained by the relevant departments are incomplete, and many advanced technologies are used in the process, so it is difficult to copy them. To this end, the technicians worked hard to master the design and production essentials of the aircraft, which made a good auxiliary foreshadowing for the design and production of the J-8 fighter in the future.
Before the eighth project, the military and aviation industry departments had put forward many unrealistic fighter plans, such as Dongfeng 107 and Dongfeng 1 13. Hasty and reckless, causing unnecessary losses. Because of the lessons of failure, we were so cautious when designing the J-8 that we didn't dare to break through the MIG model in aerodynamic layout and shape. Under the consideration of the older generation of aircraft designers, such as Tang and Huang, and drawing lessons from the aerodynamic layout of the J-7, that is, MIG -2 1 and the design idea of E- 152, the J-8 was designed into a large double-engine J-7 by using off-the-shelf technology, which improved the ceiling and climb rate. We didn't jump forward in the top five, but walked. Although this practice was of great benefit to the rapid and stable development of the J-8 at that time, it doomed its future fate, which led to its failure to become a good flight platform and had many adverse effects on future modification. In the late 1970s, faced with the MIG -23 widely deployed in the Soviet Union and Vietnam and the shadow of backfire bombers that always hung over the country, the old J-6 and J-7 were no longer qualified for the new mission of future air combat. 1980, the state decided to develop the advanced performance 歼 8Ⅱ based on 歼 8Ⅰ. Designers adopted the development mode from Soviet Union Su -9/ 1 1 to Soviet Union Su-15, and changed it to air intake on both sides, thus lengthening the fuselage proportion. I haven't got rid of the MIG, and I can still see the MIG on it. Nose radome, engine air intake, foldable ventral fin, belly double-tube 23mm gun, etc. Following the design of MIG -23, the integral cover form of engine tail nozzle is greatly influenced by MIG-19. The shape of the main wing, landing gear and retracting mode are the same as those of MIG -2 1, and some small doors can also see the design of American F-86!
In fact, if we take air superiority as our responsibility, the design of J -8II is far-fetched, so we should adopt the plans of J -99, J-13, Qiang -6 and J-H -7. 歼 9 is a fighter developed almost simultaneously with 歼 8. Due to the high performance required at that time, the scheme was changed several times, and a prototype was never built, so it was forced to dismount at 1980. Liu Qiang is a variable swept wing attack aircraft, which was developed on the basis of MIG -23 in the late 1970s. Like the J -9, it is planned to adopt a high-thrust WS-6 turbofan engine equivalent to American F 1 10 and Russian AL-3 1/,and improve the air-to-air fighter. J 13 is an air superiority fighter developed in 1970s to replace J-6. Originally planned to use WS-6, it was later changed to WP- 15 engine based on the P29-300 engine used by MIG -23, and its fate was stillborn. JH -7 is a dual-engine heavy fighter-bomber designed and produced by Xi 'an Aircraft Design Institute and Xi 'an Aircraft Manufacturing Company. It was founded in the 1970s. It uses two Spey MK202 (domestic model called WS-9) turbofan engines, with good aerodynamic layout, long range and large bomb load. It is a good flight platform with considerable improvement potential. If the fire control system is improved and replaced by WS-6 or Russian-made AL-3 1, and the longitudinal design of telex * is adopted, it can be completely improved into a multi-role fighter similar to F- 15E or Su -30MKK, which has strong air-to-air and ground (sea) attack capabilities, and its modification prospect and significance are better than that of the J-8II developed later but put into use first. The 1970s was a period when a hundred flowers blossomed in the aviation history of China, during which many projects such as Yun-10, J-12 and Zhi -6 appeared, reaching the climax of the development of China combat aircraft in the later period. Unfortunately, due to the aviation industry departments or users, most projects were eventually dismounted. Fortunately, with the persistence of the design and production units, JH 7 survived. Throughout history, users have repeatedly hesitated about what kind of combat aircraft to equip, resulting in many advanced combat aircraft with good prospects for improvement being dismounted, and none of them kept their supporting advanced engines, resulting in the failure of design teams and brain drain. Because the operational thinking of the user department stays in a short distance and intercepts the invading enemy quickly and dispersedly under the guidance of the ground, they are keen on the continuity and inheritance of the so-called tactics and are eager to improve the relatively backward J-8, so they have to choose J-8 II. At that time, the J -8II was not the only choice, nor was it the best choice. However, the reality is reality after all, and our best wishes for China's advanced fighters can only stay in the memories of that glorious history.
○○○○○○○○○○○○○○○○○○○○○○○○○○○○○967 Our army has failed in developing J 12. This aircraft is a single-engine light supersonic fighter developed in 1960s. Because of its short voyage and lack of all-weather combat capability, it dismounted in the late 1970 s. Throughout the 1960s and 1970s, the most innovative of all the aircraft that have been tested in China is the J 12. Sadly, selfie is a backward mode. However, there are several achievements worthy of special mention, such as: getting rid of the shackles of Soviet fighters and adopting lower monoplane, leading edge flap and integral windshield. And the prominent tail shaping after washing. These design concepts and technologies, which existed as early as the 1960s and 1970s, have not been applied to the future development and improvement of the J -8II. In contrast, the design style of J -8II is far less than J-12. Looking back at the design policy of the J -8II, it should be a fighter with all-weather combat capability, over-the-horizon air combat and all-round confrontation with MIG -23. In fact, the aerodynamic layout, especially the triangular wing, has limited the further development of the J-8.
Historically, the United States, Europe, the Soviet Union and other countries have equipped many delta-wing aircraft. American F- 102, F- 106 and Mirage III are all tailless delta wing fighters. Its advantage is that transonic drag is small, which is beneficial to supersonic flight, but it also has many disadvantages. The first two are interceptors, which can be used in China. Phantom III is replaced by Phantom F 1, which is not much better than the former, but the take-off performance is improved by using swept wings. Later, Mirage 2000 adopted technologies such as telex * longitudinal relaxation of static stability, which gave the tailless delta wing a new life. The magic lion developed by Israel on the basis of Mirage 5 is equipped with duck wings to improve its flight performance. Since 1990s, all the new fighters developed in Europe have adopted canard and delta wing layout. China's newly developed J 10 also adopts this layout. At that time, only the Soviet Union developed a series of delta-wing fighters such as MiG -2 1, Su -9, Su-1,Su-15. Among them, Su Huoyi has designed interceptors, and only MIG -2 1 is a frontline fighter. As a simple, efficient and low-cost daytime fighter, it is an important mode for the Soviet Union to develop into a fighter with twice the speed of sound because of its unique political and economic reasons. Although there are many unsatisfactory places, it is a fighter with twice the speed of sound, which is rare in the Eastern camp, and it has spread all over the world. From the point of view of technology and application, delta wing fighter has irreplaceable advantages and is the mainstream of combat wing type. The pure delta wing, that is, the conventional delta wing aircraft without modification, is no longer the development direction. Pure delta wings are suitable for interceptors flying at high altitude and high speed, rather than multi-role fighters and air superiority fighters. Delta wings must be modified to become excellent fighters. In order to make up for the deficiency, Sukhoi Design Bureau improved Su-15 into a double delta wing aircraft, and Cheng Fei Company improved the 歼 7 into a double delta wing 歼 7 mg or 歼 7 E with leading edge flaps. The improved J-7 fighter is a domestic fighter with the strongest combat capability. The flight performance of the J -8II is much inferior, and its only advantage is its long range. This may be the only advantage that the navy sees. Looking around the world, whether military or civil aircraft, there is no pure delta wing after the 1970s (for example, F- 15 adopts twisted tangent delta wing, and F- 16 adopts telex * longitudinal tangent delta wing). The reason is that the pure delta wing is only beneficial to the development of high-speed performance, not conducive to the development of low-speed performance, and the maneuverability and use economy are poor. As the main fighter of China in 1990s, the J-8II inexplicably kept its pure delta wing unchanged. Although it is beneficial to high-altitude and high-speed flight, the poor flight performance caused by it is not conducive to shortening the length of the fuselage, and the consequences are incalculable. It not only affects the flight, but also directly leads to the slender fuselage. Adopting pure delta wing layout is the first congenital deficiency of 歼 8Ⅱ. A large number of new materials are used, and the technological level has been improved.
As early as in the imitation process of MIG -2 1, we have mastered new technologies such as chemical milling and integral panel processing, and started to try the application of new materials. Later, after several years of efforts, composite materials have been used in the development of J-8. Mainly used for flat tail and heavy straight tail, hollow turbine blades have been used in WP-7 engine. Subsequently, China made a test flight of the all-composite vertical tail on the Wu Qiang plane. The extensive application of Dolphin Helicopter in the imitation of composite materials is a good promotion for the large-scale application of composite materials in domestic aircraft, so the application level of new technologies and new materials has reached an unprecedented level in the J-8II.
Except JH-7, the technical level of JH-8 II is the best among all domestic combat aircraft. For example, the WP- 13 engine used in the 歼 8 II uses a large number of titanium alloys and its processing technology, which greatly improves the economy and service life. All-plastic vertical tail plate and Lauren paper honeycomb structure further reduce the weight of the aircraft.
The J -8II has been widely used in navy and air force since it was put into production. It is the last fighter of the second generation in China, following the J -5, J -6 and J -7 in China. The output greatly exceeds that of 歼 8 and 歼 8 I, and the number of equipment is second only to 歼 7. In terms of long-range and all-weather operations, the first three fighters can't reach it. Only imported No.27 or J 1 1 can surpass J-8II in performance, and the latter has unique advantages in quantity and tactical application.
During the 50th anniversary parade of People's Republic of China (PRC), 28 J -8II planes flew over Tiananmen Square. Among them, 24 aircraft were arranged separately, thus becoming the largest fleet formation in the history of our army, and the other four J -8II oil receivers and two H -6F tankers. Although there are also 28 J-7 s, there are 20 separate formations, and the remaining 8 are J-7 EB of Bayi Air Show Team and long-range bombers, which form the first echelon. The above facts are sufficient to illustrate the important position of the J -8II in our aviation.
歼歼 歼 Ⅱ is the second tactical aircraft with air intake on both sides, and it is the first fighter with air intake on both sides. Since then, China fighter has abandoned the simple nose air intake form and started to have modern appearance characteristics. However, as a cross-century fighter of our army, it has a long fuselage due to insufficient optimization design. The main reason is related to the conventional layout of pure delta wings.
As the second congenital deficiency of the J -8II, the slender fuselage should not be shortened. Measured by its length, its empty weight is only 9,820kg, and its maximum takeoff weight is only 17.8t, which is similar to the single-engine MIG -23 with short fuselage length, but lower than the MIG -27' s 20.6t The cub fighter has an empty weight of 7,285kg, and its maximum takeoff weight is16.5t.. Phantom 2000 has an empty weight of 7500 kg and a maximum takeoff weight of 17 ton. Both values are lower than our machines, but their geometric dimensions are much smaller. The empty weight and maximum takeoff weight of F- 16 vary with different production batches. The empty weight is about 7.0-9.3 tons, and the maximum takeoff weight is -23. 1 ton, which has been close to the level of heavy fighter by light fighters, with small size and heavy weight. The European gust that appeared in the 1990s is similar to the European fighter typhoon, which is F- 16. By comparison, it can be found that the empty weight and maximum takeoff weight of the J -8II are not commensurate with its length, just like a tall and thin boxer, with extremely thin strength. The maximum takeoff weight of foreign fighters with the same or similar size as the J -8II is about 25-35 tons, and only domestic fighters that meet this value are J -7H. The reasons for this situation are: first, the engine thrust is small; Second, the wing shape and high lift design are unreasonable, and the landing gear strength is not enough; Third, western aircraft try to use composite materials and widely used titanium alloys to reduce weight. Because of the well-equipped electronic equipment and large-capacity internal fuel tank, the take-off weight is often relatively large, and the small take-off weight of 歼 8II can only indicate that there is less effective space. We can boldly guess that if WS-6 is used to refit 歼 8Ⅱ, it is necessary to increase the take-off weight, improve the fire control radar, and profoundly change the airfoil and aerodynamic layout. However, this is not consistent with the user's habit. Users are used to using light and simple maintenance aircraft instead of using sophisticated and complex combat systems. It is not impossible to shorten the fuselage when using the existing WP-7 or WP- 13 engines. Now, for example:
The air intakes of 1, MIG -23 and MIG -3 1 are located on both sides of the cockpit or in the back row. Fighters with normal layout, such as F-4, F-5, F- 15, F-22, Jacques -38, Super Flag, Harrier, Wu Qiang, Mirage 2000 and other tailless delta-wing aircraft, also have air inlets in the front, and the wings are further forward without flat tails, thus further shortening the fuselage.
2. For fighters with closely coupled canard layouts such as Saab-37 and JAS-39, not only the air intakes are on both sides of the cockpit, but also the front canard is placed close to the air intakes, which shortens the fuselage compared with the conventional layout; The MIG-19, MIG -2 1 and other wings are very forward, which can also shorten the fuselage.
3. In order to shorten the rear fuselage, F-15, F-22, Lightning and other fighters specially modified the trailing edge of the wing to make the root of the trailing edge move forward, which is convenient for placing the horizontal tail forward. If Su -27, MiG -3 1 and other aircraft use delta wings, it is necessary to lengthen the rear fuselage.
4. In order to shorten the fuselage length, many designers choose to expose the engine tail nozzle and move the vertical tail forward to shorten the total length of the aircraft. Some planes, such as typhoons and gusts, have their radomes in front of the cockpit. Some aircraft, such as F- 15, F-22 and F-35, have greatly shortened fuselage and relatively backward horizontal tail. F-22 also reshaped the horizontal tail of YF-22, which is similar to the main wing, which is not only more conducive to invisibility and shortening the total length, but also avoids man-machine collision during maintenance.
In short, designers rack their brains to shorten the fuselage!
On the other hand, the above measures to shorten the fuselage length were not applied to the J-8 II, but became the fighter with the largest slenderness ratio after the 1980s, which really made people feel helpless. In weapons and equipment, there must always be big and small. For example, warships, foreign warships always surpass us in size and displacement, and so do tanks. In terms of aircraft, we are always much lighter than others. As a result, like the Soviet Union, it was criticized as "stupid and big". If the optimal design is adopted, the total length of η 8Ⅱ can be shortened completely. The designer of the J -8II once said that the purpose of deliberately lengthening the length of the J -8II fuselage is to increase the fuel tank of the front fuselage to balance the center of gravity of the aircraft, which is also one of the reasons for the increase in the length of the aircraft. The solution to this problem can be to move the lower auxiliary fuel tank forward, that is, like early models such as F/A- 18, Saab-37, F-5 and Su -7, instead of increasing the length of the front fuselage. By analogy, it can be concluded that the fuselage length of the J -8II can be shortened. In this way, it is possible to become a new type of semi-fighter, rather than simply lengthening the original quasi-fighter to achieve the design goal. With the background of Lenovo's birth, poor aerodynamic layout and slender fuselage, it can be concluded that Lenovo's J-8II design is a failure. Of course, lengthening the fuselage is beneficial to reduce flight resistance and increase longitudinal stability. Due to the lack of optimal design, including the longitudinal system and pylon layout, the J -8II has grown up among lightweight athletes, and its fists and feet are weak. Foreign fighters, especially western fighters, use a lot of composite materials and titanium alloys. And do everything possible to reduce the weight of the plane. Fighters with shorter fuselage length and similar empty weight have much larger take-off weight, range and bomb load than 歼 8II, and the airborne equipment is very complete, which only shows that 歼 8II has poor lift effect, too little effective space and unreasonable overall design. Some people think that the slender 歼 8Ⅱ is inseparable from its use of two engines. It is true that the use of two engines is an important factor that leads to the lengthening of the fuselage, but it is not an absolute factor that is more slender. By optimizing the design, the total length can be completely controlled. In foreign countries, there are many examples of multiple fighters equipped with engines of the same model or similar models. In addition to heavy A-5, F-11,Su -24, etc. Other types of twin-engine aircraft have no obvious increase in fuselage length except the take-off weight (the turbojet 13 adopted by J8II is actually an improvement of turbojet 7). For example, the same turbofan engines are F/KOOC-0/00 and F/KOOC-0/0, F-/KOOC-0/6 is the single engine captain/KOOC-0/5.09 meters, and F-/KOOC-0/5 is the double engine captain/KOOC-0/9. On the basis of the two engines, replace the F-20 with an F404 turbofan engine, with the captain14.42m.. Similarly, the X-29 of an F404 is16.44m, X-3 1 yes14.85m, and JAS-39 is14m. The length of double-engine YF-22 with F- 1 19 engine is19.56m, the length of F-22 is shortened to18.92m, the length of YF-23 is 20.5m, and the length of single-engine X-32 is/kloc-0. The length of Mirage 2000 with M53 engine is 14.36m, that of Mirage 4000 with double engines is 18.70m, that of gust A with improved M53 M88 is 15.8m, and that of gust C is shortened to15.3m. These designs are from the 20th century. The previous models mainly used F 104 of J79 engine, captain 16.69m, twin-engine F-419.20m: single attack aircraft A4 of J52 engine12.29m, and double attack aircraft A-616. Egyptian engine single-shot hunter fighter length 13.93 meters, double-shot lightning interception length 16.84 meters; The length of MIG -29 equipped with two RD-33 engines is16.28m, and that of FC- 1 length14m equipped with improved RD-33 in China ... Through the comparison of examples, it is clear that the fighter's length is indeed related to the number of engines used, but it will not cause obvious fuselage lengthening. The 歼 8 was developed from 歼 7, using the same or similar engines. The length of 歼 7 is13.95m, the length of 歼 8 including pitot tube is 21.52m, and 歼 8 II is 21.59m.. Compared with the aircraft mentioned above, the growth rate is too large, but the take-off weight is too small, which is a pity.
If we hadn't simply enlarged the J-7 at the beginning, but carefully revised the aerodynamic layout and some details according to the tactical objectives, and selected the best scheme from many schemes, the J-8 aircraft would never be like this. In addition to the lack of optimized design and modification of the wing, fuselage and aerodynamic layout, there are other problems, such as simple wing lift device, poor landing gear retraction form, small cockpit, too big and stupid ventral fin and so on. It should be pointed out that some designs of the 歼 8II are too simple because the thrust of the engine is too small, but it is precisely because of the small thrust that it is necessary to shorten the fuselage, reduce the weight and increase the lift of the aircraft, which is precisely a major problem of the 歼 8II.
The high-lift device and landing gear retraction form of the J-8 are inherited from MIG -2 1, and there are simple flaps on the wing, neither leading edge flaps nor F- 15 wing torsion like lightning. Because the main landing gear strut is under the wing, it inclines inward and forwards into the fuselage, and the pylon inside the wing can only carry combat missiles, while the pylon near the main landing gear strut cannot carry large auxiliary fuel tanks, which is not conducive to increasing the load and voyage. If the wing shape and lift mode are changed, and the main hanger extends vertically inward into the fuselage, the load capacity of the wing 歼 歼 II will be improved. The layout and practice of F-4, Typhoon and Mirage 2000 are proof. As for the narrow cockpit, the tail wing on the fuselage, the wing knife on the wing and the anti-vibration counterweight on the horizontal tail wing are all common faults that imitate MIG aircraft. The foldable ventral fin introduced by MiG -23 is not helpful to reduce the weight and operating cost of the aircraft. The engine has small thrust and high fuel consumption.
Engine is one of the two bottlenecks restricting the development of aircraft in China, and J-8II is no exception. Two WP-7 engines are installed on the JVIII. JVIII II modified WP- 13 is an improved version of WP-7, which is an imitation of P 1 13 turbojet engine developed by the Soviet Union. Both belong to the technical level of the 1950s, and the domestic model of the former is WP-7. The two have only slight changes and are universal. WP- 13 dead weight 1306kg, afterburner thrust 63.45kN, thrust-to-weight ratio 5.28, fuel consumption rate of take-off phase 2.2kg/kg/ hour, and fuel consumption rate of cruise phase 0.99kg/kg/ hour. Although we always insist on improving WP- 13, the improvement is not significant due to technical limitations. Due to the small thrust of the engine, the takeoff weight of the J -8II is limited, and the high fuel consumption rate further shortens the range of the aircraft.
Since 1970s, the advanced turbofan engines have been used in the third generation fighters in the west. Compared with turbojet engine, it has the advantages of large thrust, low noise and low fuel consumption. In 1980s, the turbofans of western fighters were basically realized, and even the countries and regions around China basically realized the turbofans of main fighters. However, we still rely on the financial resources given by the Soviets in the 1950s and 1960s to equip the main fighters in the 1990s. This alone has seriously restricted the performance of our military aircraft. At present, similar military engines in the west have developed to miniaturization, with smaller geometric size and lighter weight, but higher thrust and thrust-to-weight ratio, and thrust vector engines have appeared. The engine control technology adopts full digital control system, and the longitudinal and vertical restrictions are getting smaller and smaller. In contrast, the overall level of China's engines is still backward. Shortly after the establishment of the J -8 project, we began to develop WS-6 turbofan engines with the same thrust as AL-3 1 F-10010, and implemented the WS-8 plan to improve WP-6 to WS-5, mapping and imitating Boeing 707 and 707. However, even the test run of 1982 has achieved the expected goal. It is hard to imagine that at the same time that AL-3 1 and F- 100 were developed, we actually had similar turbofan engines, but we dismounted because there was no supporting aircraft. The successful imitation of WS-9 stopped at first without using the plane, which led to the finalization of the JH -7, which had no engine and a small number, greatly affecting the combat effectiveness of our army. When WS-6 dismounted, the engine was almost in a finalized state and only needed to be put into production. WS-6 used to be our promising engine, which not only improved the combat effectiveness of our army, but also greatly improved the overall level of the aviation industry. Its dismantling, as well as the dismantling of the ninth and tenth fighter planes, has held back China's aviation industry.
The purpose of developing the J -8II is to install a large fire control radar in the nose radome to achieve all-weather, over-the-horizon air combat and interception capabilities. However, judging from a large number of photos published by the 歼 8Ⅱ, the 歼 8Ⅱ M plan and the current improvement, it is impossible for the 歼 8Ⅱ to be equipped with downward-looking pulse Doppler radar. Its fire control radar is at most equivalent to the high-altitude lark of MIG -23 or the early model of F-4. China's medium-range air-to-air missile PL- 1 1 is an imitation of Italian Aspide. Judging from the fact that HQ-7 ship-to-air missile finally replaced HQ-6 1 ship-to-air missile in China missile frigate, PL- 1 1 has average performance, but it seems that the fire control radar of J-8II is not suitable for it. This conclusion can be seen from the fact that the J -8II only carries combat missiles but not PL- 1 1 missiles. The design concept of the J-8 is a high-altitude and high-speed interceptor. As an interceptor, it is characterized by advanced fire control radar and medium-range air-to-air missile, but in this respect, J-8 and J-8 II are not enough. There is no outstanding flight performance when performing combat missions. It is the third congenital deficiency of the J-8II to improve the interceptor that mainly intercepts bombers into a fighter that mainly controls air superiority, and the backwardness of avionics is the second bottleneck that restricts the development of China aircraft. China has successfully developed a pulsed Doppler radar. I don't know why JH-8 II is not equipped except JH-7. It is a good choice to equip the plane with this kind of radar.
As a new fighter of our army, the 歼 -8II carries no more weapons than the 歼 -72, mainly a 23mm double-barrel gun with 2-4 combat missiles for air combat missions. Carry two rocket launching nests and 4- 10 bombs to carry out ground attack missions. At present, there are no reports of carrying precision guided weapons and anti-ship weapons. In the HNA sequence, Wu Qiang does not have the ability to carry C80 1 anti-ship missiles. Although JH-7 can carry 2-4 pieces, its equipment is too small. JH-8 II can't carry and launch C80 1, which greatly reduces its combat capability as a naval aircraft.
The reasons for the lack of operational flexibility and inflexibility of the J -8II are related to the small bomb load and range. More importantly, the fire control radar of this aircraft is backward, which restricts its operational potential. This may be the reason why China develops modern science.
As early as the beginning of the service of the J -8II, some insiders claimed that the aircraft completely surpassed the MIG -23 in performance. The design goal of J-8Ⅱ is to resist the challenge of MIG -23, the last second-generation fighter in the Soviet Union, and draw many lessons from the later design. MiG -23 entered service nearly 20 years earlier than J -8II, and its designer was the famous MGO Design Bureau. When designing this aircraft, there were several generations or batches of world-famous fighters, including MiG-17/ 19/2 1 copied by China. In order to develop MIG -23, they have done a lot of pre-research on related technologies and mastered many new technologies. More importantly, the Soviet Union made every effort to develop its air superiority over NATO. After service, the performance of MIG -23 has been continuously improved. It is not only equipped with medium-range air-to-air missiles, but also has a certain ability to look down and shoot down. The maximum speed and maneuverability at high altitude are superior to our plane. P29-300 turbojet engine is not only powerful and full of vigor, but also the acme of its kind, reaching its peak. The previous generation P 13 engine WP- 13, which imitates P29-300 in China, cannot be compared with it. Moreover, the number of MIG-23 is far more than that of 歼 8 II, which has not only qualitative advantages, but also quantitative advantages. Up to now, there is still a lot of room for improvement. Our plane is designed to catch up with MIG -23. After the successful imitation of MIG -2 1, it is difficult to develop an aircraft that can catch up with MIG -23 when the industrial strength, especially the aviation industry, lags behind the Soviet Union. Moreover, our design can't get rid of the influence of the Soviet Union, lacking enthusiasm for high-performance fighters, and making mistakes constantly. The small aspect ratio, conventional delta wing layout and backward design ideas seriously restrict the potential of the J -8II, making it unable to fully compete with the MIG -23. As the last second-generation fighter in the world, the J-8II not only lags behind MIG -23, but also is in the downstream compared with other major second-generation fighters such as F- 104, F-5, F-4, Mirage III, Mirage F 1 and Saab -37. Those remarks that the J -8II surpasses other second-generation fighters, has some characteristics of the third-generation fighters, and surpasses some performances of F- 16 and Mirage -2000 are unfounded and unfair. The last modification of F- 104, the world's first fighter with twice the speed of sound, is already an excellent interceptor, capable of launching medium-range missiles programmed by sparrows or spiders, and its interception performance exceeds that of J -8II. After the 1980s, the F-4 has been greatly improved, and its performance completely exceeds that of the later 歼 8Ⅱ and 歼 8Ⅱ M.. Even without upgrading, its operational flexibility and comprehensive operational capability still far exceed our aircraft. The combat capability of the F-5 is roughly equivalent to that of the J-8II, and its final improved F-20 has reached the level of the third generation fighter because it is equipped with AN/APG-67 pulse Doppler radar and external management system, vitrified cockpit and F404 turbofan engine. It was only because the Reagan administration released the export restrictions of the high-performance fighter F- 16 that it was forced not to formally produce it. Saab -37 is the same as F-4. F- 16 and Mirage -2000 are typical third-generation light fighters, each with its own strong points, which are excellent in interception, combat and ground attack.