As you know, today in the armament of the air forces of the most developed countries of the world, one cannot find a single 5th generation multipurpose fighter in a two-seat version. Almost all existing aerospace corporations-leaders and design bureaus specializing in the development and serial production of promising stealth tactical aircraft systems focus their efforts on fine-tuning single-seat modifications with the most saturated, convenient and easy-to-use cockpit information field.
The main emphasis is on the development of large wide-format windshield indicators and helmet-mounted target designation devices that allow just one pilot to perfectly navigate the most difficult tactical air conditions. For example, to this day, helmet-mounted target designation systems such as Shchel-ZUM, Sura, Sura-K were installed on multipurpose fighters of the 4/4 + / 4 ++ generations (from MiG-29 to Su-35S) and "Sura-M", intended only for visual guidance of a round capture marker at a target, followed by its capture and launch of R-73 and R-27ET missiles in close air combat.
In the coming years, it will be replaced by a fundamentally new system "Hunter" from JSC "Ryazan State Instrument Plant" (part of "KRET"). The software for the Hunter's helmet-mounted indicators, in addition to various target acquisition markers, will have the ability to project the terrain in front of the pilot's eyes when flying in adverse weather conditions at extremely low altitudes (including at night). The image of the relief transmitted through the elements of the fuselage of the combat vehicle will be formed on the basis of data obtained from the synthetic aperture mode of the radar, as well as various optoelectronic complexes of the OLS-K type (optoelectronic sensor for viewing the lower hemisphere of the MiG-35) or "Mercury" (low-level container surveillance and sighting system with infrared sighting channel). Also, at the moment of close combat or, for example, shifting the gaze to the missile-hazardous direction after the irradiation warning system is triggered, the Hunter will allow the pilot to see the familiar sign-graphic information on the helmet-mounted display, represented by altitude, flight speed, direction, overload, and artificial horizon. All these data are duplicated from ILS and MFI on the dashboard
In the United States, a similar NSC for the 5th generation F-35 fighters was named HMDS (Helmet-Mounted Display System), in addition to being used as part of the Lightning avionics, by 2017 it is planned to gradually integrate it into the weapons control system of air superiority fighters F -22A "Raptor", which will allow their pilots to carry out safe piloting in the mode of following the terrain, as well as dogfight "over the shoulder" with AIM-9X "Sidewinder" missiles. But, as they say, two pairs of eyes are better than one, and therefore two-seater fighters have a number of tactical and ergonomic advantages noted in Phantoms, Super Tomkats, Super Hornets, MiG-35 and Su-30SM.
Multifunctional indicators on the dashboard of the systems operator are duplicated with those installed in the cockpit and almost always have advanced capabilities for working with the modes of radar and optoelectronic systems, as well as with equipment for exchanging data on tactical situations. During long and complex aerial operations with multiple refuelings in the air, crew members can take turns, providing a delay in fatigue for several more hours. In air combat, the psychological load on the pilot is significantly reduced, who can concentrate on piloting the car, while the operator, without being distracted by the controls of the fighter, can fight the enemy, focusing on the work of the airborne radar, OLS, as well as the helmet-mounted target designation system … All these advantages were taken into account when creating a two-seat Su-30 based on the Su-27UB, which was originally conceived as a multipurpose air defense interceptor capable of hovering over a theater of operations for hours, gaining air supremacy while simultaneously searching for and destroying enemy small cruise missiles and other means air attack.
It is worth noting that in most air missions of the 21st century, where in some parts of the theater of operations there can be from tens to hundreds of sea and ground air defense systems, electronic warfare systems, as well as enemy fighters, it is the "Sparks" that are potential contenders for the role of the dominant part of tactical aviation. And it is no coincidence that in the military doctrine of India, a large percentage of promising FGFA fighters planned for serial production is assigned to two-seat modifications. But today I would like to tell you about a very interesting version of the radical modernization of the Chinese JH-7 / 7A Flying Leopard two-seat multipurpose fighter-bomber to a very effective and advanced stealth version of the JH-7B. Considering that the series of produced aircraft exceeds 240 units, the JH-7B "Flying Leopard" aircraft fleet may temporarily become the largest among the 5th generation two-seat tactical fighters.
Despite the classic design of the plane, similar to the Western tactical strike fighters of the beginning of the 70s, even the first version of the JH-7 QUALITATIVELY EXCEEDED THEM IN BASIC TECHNOLOGIES
To begin with, let's get acquainted with the history of the origin of the JH-7 "Flying Leopard", which goes back to the period of close cooperation between the Aviation Design Institute No. 603 (PRC) with the Yugoslav Air Force Technical Institute and the Romanian National Institute of Science and Technology in 1972 - 1973 … It was then, after the military conflict on Damansky Island, that Beijing was looking for points of contact with Eastern European states that did not show sympathy for the USSR. The purpose of the search was to temporarily replace the lost stable military-technical cooperation with the USSR, which was restored only in the early 90s. As you remember, it was by the end of this crisis period (in 1987) that the drawings of the Israeli prototype of the Lavi multipurpose fighter, designed on the basis of the F-16A / C purchased from the USA, fell into the hands of Chinese specialists, which resulted in the appearance of the light MFI J- 10A.
As for the cooperation of the above institutions, the Chinese worked here just flawlessly: they took the design drawings of the airframe of the Yugoslav-Romanian light subsonic attack aircraft J-22 "Orao" 1). The design of various elements of the airframes of the British Tornado ADV fighter-interceptor and the Jaguar fighter-bomber, which also took as a basis the reduced Orao airframe, played an important role in the refinement. The nose section with the JH-7 cockpit, as well as the air intakes were identical to the nose design of the Jaguar, the tail section with the nozzles of the turbojet engines and one vertical stabilizer repeated the design of the Tornado. Considering that, unlike the assault Yugoslav-Romanian "Orao", the JH-7 was developed by a supersonic machine, the center section of the high wing is shifted closer to the tail section to ensure optimal aerodynamic focus at supersonic speeds. The JH-7 glider allows for a more or less high-speed steady turn, which is facilitated by the all-turning large elevators and a wing with an area of 52.3 m2. At least the Flying Leopard is significantly more agile than the British-French Jaguar. In addition, the well-calculated layout of the volumes and geometry of the engine nacelles of the Chinese strike fighter at that time allowed the installation of powerful British turbojet engines WS-9 Rolls-Royce Spey 202/203 with an afterburner thrust of 7711 kgf (total thrust of 2 engines 15422 kgf), purchased from the UK, and previously installed on deck modifications of the F-4K ("Phantom FG. Mk1").
With a normal takeoff weight of the JH-7 of 21.5 tons, a very decent thrust-to-weight ratio of 0.71 was obtained (the Jaguar had about 0.66, the shock Tornado GR.4 had 0.7), and this was already then inspired the idea of endowing the JH-7 with the qualities of an air superiority fighter, but such ideas were voiced only after 2010. Prior to this, the aircraft had come a long way from the start of small-scale production by the facilities of the Xi'an Aircraft Corporation XAC in 1987, with the subsequent transfer of 18 aircraft to the Chinese fleet and the "freezing" of the program, to the resumption of large-scale production, around 2002, already with new improved by-pass turbojet engines -Analogues of the British "Speyev" WS-9 "Quinling" from the "Xian" company. The total thrust of the two Chinese units was already 18400 kgf, which gave the upgraded fighter-bomber a thrust-to-weight ratio of 0.86. For this indicator, the level of the domestic high-precision strike fighter-bomber Su-34 with AL-31FM1 engines was even slightly exceeded. In the period from 1995 to 2001, a comprehensive modernization of prototypes was carried out from the JH-7 version to the updated version of the JH-7A.
Before the final decision was made regarding the installation of the WS-9 engine on the twin, the cockpit was armored, the first pilot's visual view was improved by installing a new three-section canopy with an uninterrupted frontal segment, and a second ventral aerodynamic keel was added. The structural elements of the wing and fuselage have also been strengthened, giving the updated JH-7A airframe a larger G-limit.
Airborne electronic weapons have also been improved in accordance with the requirements of the first decade of the 21st century. Its main element is a multifunctional airborne radar with a slotted antenna array JL-10A. Despite the weak energy potential (the detection range of air targets with RCS of 3m2 is only 85 - 100 km), the station is multi-channel, and is capable of detecting and tracking 15 air targets on the way. The number of targets "captured" for firing is: 2 - for air-to-air missiles with a semi-active radar seeker of the PL-10/11 type and 4-6 for modern missiles with an ARGSN of the PL-12/15 type. There is information that the multi-channel JL-10A became possible thanks to the purchase from the Iranian Air Force in the 80s. an AN / AWG-9 radar kit from the F-14A "Tomcat" fighter-interceptor control system. And this is fully consistent with reality, because the replacement of the radar was carried out in the 90s, in complete secrecy. Nevertheless, the radio-electronic technologies existing at that time in the Celestial Empire did not allow the Chinese 607th CLETRI Institute to realize the JL-10A operating range at the level of the American AN / AWG-9 station (240 km). Later, the element base of the Chinese radar was supplemented with an information and control bus of the MIL-STD-1553B standard, which allows integrating numerous types of Chinese and foreign weapons of the "air-to-surface" and "air-to-ship" class.
On the JH-7A hangers, various Chinese-developed electronic reconnaissance containers were seen more than once, used for operational programming in the air and launching anti-radar missiles of the YJ-91 type (analogue of the Kh-31P) at radio-emitting targets. Also, photos were provided from the container suspended electronic warfare stations and the container optical-electronic complex with a laser designator for illuminating enemy ground targets to guided aerial bombs with a semi-active laser homing head of the TG-250/500/1000 type. The system for receiving and displaying telemetry information on the MFI allows pilots to use guided bombs with a television homing head of the YJ-88KD type.
Reinforced airframe design allowed to increase the JH-7A combat load from 6500 to 7500 kg, as well as to expand the number of suspension points from 6 to 11. Heavy subsonic anti-ship missiles C-801, C-802 and C-802A (range up to 180 km), it is possible to integrate promising supersonic anti-ship missiles of the YJ-18 type with a flight range of 220 to 540 km and a speed of 2650 - 3200 km / h, which turns these tactical fighters into "aircraft carrier killers." The JH-7A "Flying Leopard-II" has a decent combat radius of 1,650 km, allowing for strike operations and interception of air targets within the Spratly archipelago, the Philippines, Taiwan, Japan and South Korea without air refueling. For example, the participation of light multipurpose J-10A fighters in combat missions within these states is difficult, since the range without refueling and PTB is only 800 km. In the meantime, in the course of the development of the Flying Leopard-II program, at the 603rd Institute, as well as at the XAC aircraft manufacturing plant, a preliminary study of the appearance of the next generation tactical fighter based on the JH-7A began. The new vehicle was named JH-7B. At least 4 variants of the airframe design were considered.
The first is a classic vysokoplane with a trapezoidal wing and a reverse sweep along the trailing edge. A single-section vertical tail unit (one stabilizer) was used, as it was implemented on the Tornado, F-111A and Typhoon. The shape of the unregulated air intakes is exactly the same as that used on the F-35, which ensures a maximum speed of no more than 1900 km / h. It should be noted that on the JH-7 and JH-7A versions, small unregulated air intakes also did not allow exceeding the speed of 1800 km / h, which was observed in SEPECAT "Jaguar" and MiG-27 fighter-bombers. The double sweep stabilizer has a characteristic kink along the leading edge (on the JH-7A it was a smooth transition) at 1/3 of the height from the root. This was done, apparently, to parallelize the angle of the keel with the angle of the ribs of the nose of the fuselage to reduce the radar signature of the JH-7B when irradiated by ground-based radar systems of enemy anti-aircraft missile systems, especially during low-altitude flight and the location of enemy radars in corners +/- 15 - 30 degrees relative to the heading direction of the fighter. As can be seen in the image, to further reduce the RCS, the cockpit has a three-section canopy with two narrow bindings without additional small windows, as is done on the existing versions of the Flying Leopard (JH-7 / 7A), as is done on a flying prototype of a Japanese promising fighter ATD-X "Shinshin".
The second version is represented by a mock-up on a wooden stand, captured in one of the design institutes of the Middle Kingdom. Before us is a similar glider with a high wing, but auxiliary aerodynamic planes have appeared - the front horizontal tail on the upper ribs of the air intakes,as well as 2 tail stabilizers with a 25-30-degree camber angle to reduce the radar signature of the vehicle. The air intakes here are similar to the first option, but the cockpit canopy is completely uninterrupted and fully complies with the American school of stealth technology. This variant is a single-seat fighter. Judging by the appearance of the fuselage, internal weapons compartments could also be provided.
The third version has a straight swept wing, as well as structural ribs offset to the center of the fuselage nose. This arrangement of ribs is implemented in the American 5th generation fighters of the F-35 family. According to the sketch, this version also provides a two-keel oblique vertical tail with trapezoidal stabilizers of an isosceles type, the analogs of which are present in the stealthy F-22A "Raptor" fighter. The three-section canopy with a minimum (double) cover is very similar to the cockpit canopy of the Japanese ATD-X fighter jet.
The fourth version of the JH-7B is considered today the closest to being embodied in hardware. It represents the first version, but with an inclined two-fin tail. The estimated area of a large trapezoidal wing with a reverse sweep for this machine can reach 65 m2 versus 52.3 m2 for the JH-7A, a span of 15.5 m against 12.8 m, respectively. Considering that the modified JH-7B airframe will be represented by the presence of a large number of elements made of composite materials, the mass of an empty vehicle can remain at the level of 15-16 tons, and the normal take-off weight will not exceed 22, 5-23 tons, this indicates a sharp decrease normal wing loading of a smaller area: it can range from 325 to 350 kg / m2. Such parameters are typical for the T-50 PAK-FA, YF-23 "Black Widow II" and "Mirage-2000-5". The JH-7B will have the maneuverability of modern Super Hornet or F-35C fighters. In addition to the wing area, this will be facilitated by influxes at the root parts of the wing, as well as increased to about 1, 1 thrust-to-weight ratio after installing more high-torque versions of the WS-9A, or the Chinese turbojet engine LM WS6 with a total thrust of 24600 kgf. One of the 10 prototypes of this engine was successfully tested back in 1982, but due to the "freeze" of the promising fighter program, during the crisis period in relations with the USSR, the LM WS6 project of Liming Engine Manufacturing also had to be scrapped.
The upgraded JH-7B will receive more capacious fuel tanks: the fuel mass will increase to 8000-8500 kg, together with a larger wing area, this will give a 20-25% greater range, which can exceed 2000 km. The aggregate combat potential for accomplishing the air-to-sea, air-to-surface and air-to-ship missions can in some respects surpass even the data of the acclaimed stealth striker J-20, especially considering the fact that the double JH-7B with a maximum pilots' dashboards stuffed with display equipment will be able to work much faster than a single J-20; and the maneuverability in close air combat in the latest version of the Flying Leopard will be much higher. It is certainly possible to flatter oneself excessively with this machine in the 21st century, but very carefully, because “half a foot” it is still in the “4 ++” generation. The bulk of the guided air combat missiles will be located on the outer underwing hardpoints. A similar situation will develop with anti-ship and anti-radar missiles, and therefore even the EPR of the J-20 multipurpose fighter in this case should not even be dreamed of: at best, this figure (with suspensions) for the JH-7B will be 1 - 1.5 m2, without them - within 0.5 - 0.7 m2. Enemy radar systems will be able to detect and operate at such a target from distances limited by only 15 - 25% compared to other Chinese fighters of the 4 + / ++ Su-30MKK or J-10A / B generation.
At the same time, after the complete modernization of the entire aircraft fleet from 240 JH-7A to version "B", the capabilities of long-range tactical operations, including gaining air superiority over the near seas, will significantly increase in the Celestial Empire.
