Su-47 "Berkut" - experimental multipurpose fighter

2024 Author: Matthew Elmers | [email protected]. Last modified: 2023-12-16 21:49

Description of the aircraft

At the end of September 1997, a historic event took place in the history of Russian aviation - the flight of a new experimental aircraft, the Su-47 "Berkut", took place, which could become a prototype of the fifth-generation domestic fighter. A predatory black bird with a white nose, breaking away from the concrete of the runway of the airfield in Zhukovsky, quickly disappeared into the gray sky near Moscow, announcing with the thunder of its turbines the beginning of a new stage in the biography of Russian fighter aircraft.

Research into the appearance of a fifth-generation fighter began in our country, as in the United States, in the mid-1970s, when the fourth-generation aircraft - the SU-27 and MiG-29 - were only making their "first steps". The new aircraft were supposed to have a significantly higher combat potential than their predecessors. Leading industry research centers and design bureaus were involved in the work. Together with the customer, the main provisions of the concept of the new fighter were gradually formulated - multifunctionality, i.e. high efficiency in the defeat of air, ground, surface and underwater targets, the presence of a circular information system, the development of cruising flight modes at supersonic speeds. It was also envisaged to achieve a dramatic decrease in the aircraft's visibility in the radar and infrared ranges in combination with the transition of on-board sensors to passive methods of obtaining information, as well as to modes of increased stealth. It was supposed to integrate all available information tools and create on-board expert systems.

The aircraft of the fifth generation was supposed to have the ability to carry out all-round bombardment of targets in close air combat, as well as to conduct multi-channel missile firing during long-range combat. Provided for automation of control of onboard information and jamming systems; increased combat autonomy due to the installation of a tactical situation indicator in the cockpit of a single-seat aircraft with the ability to mix information (ie, simultaneous output and overlapping on a single scale of "pictures" from various sensors), as well as the use of telecode systems for information exchange with external sources. The aerodynamics and onboard systems of the fifth generation fighter were supposed to provide the ability to change the angular orientation and trajectory of the aircraft without any noticeable delays, without requiring strict coordination and coordination of the movements of the control bodies. The aircraft was required to "forgive" gross piloting errors in a wide range of flight conditions.

It was planned to equip the promising aircraft with an automated control system at the level of solving tactical problems, which has an expert mode "to help the pilot".

One of the most important requirements for the Russian fifth generation fighter was "super maneuverability" - the ability to maintain stability and controllability at angles of attack of 900 or more. It should be noted that "super-maneuverability" originally figured in the requirements for the American fifth-generation fighter, which was created, almost simultaneously with the Russian aircraft, under the ATF program. However, in the future, the Americans, faced with the intractable task of combining low visibility, supersonic cruising speed and "super maneuverability" in one aircraft, had to sacrifice the latter (the maneuverability of the American ATF / F-22 fighter is probably only approaching the level achieved on the modernized aircraft Su-27, equipped with a thrust vector control system). The refusal of the US Air Force to achieve super-maneuverability was motivated, in particular, by the rapid improvement of aviation weapons: the appearance of highly maneuverable all-aspect missiles, helmet-mounted target designation systems and new homing heads made it possible to abandon the mandatory entry into the enemy's rear hemisphere. It was assumed that air combat would now be conducted at medium ranges, with the transition to the maneuverable stage only as a last resort, "if something was done wrong."

However, in the history of military aviation, they have repeatedly abandoned close maneuverable air combat, but later theoretical calculations were refuted by life - in all armed conflicts (with the exception, perhaps, of the fake "Desert Storm") fighters that entered combat at long ranges, such as as a rule, they transferred it to shorter distances and often ended with a marked cannon burst, and not a rocket launch. A situation is predicted when the improvement of electronic warfare systems, as well as a decrease in the radar and thermal signature of fighters will lead to a drop in the relative effectiveness of long and medium-range missiles. In addition, even when conducting long-range missile combat using weapons of approximately equal capabilities by both sides, the enemy who will be able to quickly orient his fighter in the direction of the target will have an advantage, which will make it possible to make fuller use of the dynamic capabilities of his missiles. Under these conditions, it is of particular importance to achieve the highest possible angular velocities of unsteady turn at both subsonic and supersonic speeds. Therefore, the requirement for super-maneuverability for the Russian fifth generation fighter, despite the complexity of the problem, remained unchanged.

As one of the solutions providing the required maneuvering characteristics, the use of a forward swept wing (KOS) was considered. Such a wing, which provides certain layout advantages over a straight swept wing, was tried to be used in military aviation back in the 1940s.

The first jet aircraft with a forward-swept wing was the German Junkers Ju-287 bomber. The car, which made its first flight in February 1944, was designed for a maximum speed of 815 km / h. In the future, two experienced bombers of this type went to the USSR as trophies.

In the first post-war years, our country conducted its own research of KOS in relation to high-speed maneuverable aircraft. In 1945, on the instructions of the LII, designer P. P. Tsybin began the design of experimental gliders intended for testing the aerodynamics of promising fighters. The glider climbed, towed by the aircraft, and dived to accelerate to transonic speeds, including the powder booster. One of the gliders, LL-Z, which entered trials in 1947, had a forward-swept wing and reached a speed of 1150 km / h (M = 0.95).

However, at that time, it was not possible to realize the advantages of such a wing, tk. KOS turned out to be especially susceptible to aerodynamic divergence, loss of static stability when certain values of speed and angles of attack were reached. Structural materials and technologies of that time did not allow the creation of a forward-swept wing with sufficient rigidity. The creators of combat aircraft returned to reverse sweep only in the mid-1970s, when in the USSR and the USA they began to study the appearance of a fifth-generation fighter. The use of KOS made it possible to improve controllability at low flight speeds and increase aerodynamic efficiency in all areas of flight modes. The forward-swept wing arrangement provided better articulation of the wing and fuselage, as well as optimized the pressure distribution on the wing and PGO. According to the calculations of American specialists, the use of a forward-swept wing on an F-16 aircraft should have led to an increase in the angular rate of turn by 14%, and the radius of action by 34%, while the take-off and landing distance was reduced by 35%. The progress of aircraft construction made it possible to solve the problem of divergence through the use of composite materials with a rational arrangement of fibers, which increases the rigidity of the wing in the given directions.

However, the creation of the CBS posed a number of complex tasks, which could be solved only as a result of large-scale research. For these purposes, in the United States, by order of the BBC, the Gruman X-29A aircraft was built. The machine, which had the Duck aerodynamic design, was equipped with a KOS with a sweep angle of 35╟. The X-29A was a purely experimental machine and, of course, could not serve as a prototype for a real combat aircraft. In order to reduce the cost in its design, components and assemblies of serial fighters were widely used (the nose of the fuselage and the front landing gear - from the F-5A, the main landing gear - from the F-16, etc.). The first flight of the experimental aircraft took place on December 14, 1984. Until 1991, the two aircraft built made a total of 616 flights. However, the X-29A program did not bring laurels to its initiators and is regarded in the United States as unsuccessful: despite the use of the most modern structural materials, the Americans did not manage to fully cope with aerodynamic divergence, and KOS was no longer considered an attribute of promising Air Force fighters and The US Navy (in particular, among the many layouts studied under the JSF program, there were no forward-swept aircraft).

In fact, the American strategic cruise missile Hughes AGM-129 ASM, designed to arm B-52 bombers, was the only aircraft with a KOS that entered the series. However, in relation to this aircraft, the choice of a forward-swept wing was primarily due to considerations of stealth: the radar radiation reflected from the leading edge of the wing was shielded by the rocket body.

Work on the formation of the appearance of a domestic maneuverable aircraft with KOS was carried out by the largest aviation research centers of the country - TsAGI and SibNIA. In particular, at TsAGI, a model of an aircraft with a KOS, made on the basis of the MiG-23 aircraft, was blown through, and in Novosibirsk the layout of the SU-27 with a forward-swept wing was studied. The existing scientific groundwork allowed the Sukhoi OKW to tackle the unprecedentedly difficult task of creating the world's first supersonic combat aircraft with a forward-swept wing. In 1996, a photograph of a model of a promising fighter with a KOS, shown to the leadership of the Russian Air Force, came to the pages of the aviation press. Unlike the American X-29A, the new machine was made according to the "triplane" scheme and had a two-fin vertical tail. The presence of a brake hook suggested the possibility of a ship-based fighter. The wingtips housed air-to-air missile launchers.

In the summer of 1997, the prototype of the fifth generation fighter of the Sukhoi Design Bureau (as well as its "rival" MAPO-MIG, known as "1-42") was already on the territory of the Gromov Flight Research Institute in Zhukovsky. In September, high-speed taxiing began, and on the 25th of the same month, the plane, which learned the working index of the Su-47 and the proud name "Berkut", piloted by test pilot Igor Votintsev, made its first flight. It should be noted that the Russian aircraft lagged behind its American rival - the first experienced Lockheed-Martin F-22A Raptor (Eagle-Burial) fighter by only 18 days (the Raptor made its first flight on September 7, on September 14 it again took off, after which flights were stopped until July 1998, and the F-22A was put on completion).

Let's try to get an idea of the new aircraft of the Sukhoi Design Bureau, based on photographs of an experimental aircraft, as well as a few materials about the Su-47, published on the pages of the Russian and foreign press.

"Berkut" is made according to the "longitudinal integral triplane" aerodynamic design, which has become a trademark feature of the aircraft of this OKW. The wing smoothly mates with the fuselage, forming a single bearing system. The features of the layout include developed wing influxes, under which unregulated air intakes of the engines are placed, having a cross-sectional shape close to a sector of a circle.

The airframe of the aircraft is made with extensive use of composite materials (CM). The use of advanced composites provides an increase in weight efficiency by 20-25%, a resource - by 1.5-3.0 times, a material utilization factor of up to 0.85, a decrease in labor costs for manufacturing parts by 40-60%, as well as obtaining the required thermophysical and radio technical characteristics. At the same time, experiments carried out in the United States under the F-22 program indicate a lower combat survivability of CFRP structures in comparison with structures made of aluminum and titanium alloys.

The wing of the fighter has a developed root part with a large (about 750) right angle sweep along the leading edge and a cantilever part with a forward sweep smoothly mating with it (about 200 along the leading edge). The wing is equipped with flaperons, which occupy more than half of the span, as well as ailerons. Perhaps, in addition to the front, there are also deflectable socks (although the published photos of the Su-47 do not allow us to make an unambiguous conclusion about their presence).

The all-moving front horizontal tail (PGO) with a span of about 7.5 m has a trapezoidal shape. Its sweep angle along the leading edge is about 500. The rear horizontal tail of a relatively small area is also all-turning, with a sweep angle along the front, except for about 750. Its span is about 8 m.

The two-fin vertical tail with rudders is attached to the center section of the wing and has a "camber" outward.

The canopy of the Su-47 cockpit is almost identical to that of the Su-27 fighter. However, on the model of the aircraft, the photograph of which appeared on the pages of foreign press, the flashlight is made flawless, like that of the American Raptor (this improves visibility, helps to reduce radar signature, but complicates the ejection process).

The main one-wheeled landing gear of the Su-47 are attached to the fuselage and retracted forward in flight with the wheels turning into niches behind the engine air intakes. The front two-wheel support retracts into the fuselage forward in the direction of flight. The chassis base is approximately 8 m, the track is 4 m.

The press reported that the prototype aircraft was equipped with two engines of the Perm NPO Aviadvigatel D-30F6 (2x15500 kgf, dry weight 2x2416 kg), which were also used on MiG-31 interceptor fighters. However, in the future, these turbofan engines will obviously be replaced by fifth-generation engines.

There is no doubt that the new machine uses the most modern on-board equipment created by the domestic industry - a digital multichannel EDSU, an automated integrated control system, a navigation complex, which includes an INS based on laser gyroscopes in combination with satellite navigation and a "digital map", which have already found application on such machines as Su-30MKI, Su-32/34 and Su-32FN / 34.

The aircraft is likely to be equipped (or will be equipped with) a new generation of integrated life support and crew ejection systems.

To control the aircraft, as well as on the Su-47, it is likely that a lateral low-speed control stick and a strain-gauge throttle are used.

The location and size of the antennas of the boron radio-electronic equipment testifies to the desire of the designers to provide all-round visibility. In addition to the main radar, located in the nose under the ribbed fairing, the fighter has two rear-view antennas installed between the wing and engine nozzles. The socks of the vertical tail, wing overflow and VGO are also probably occupied by antennas for various purposes (this is evidenced by their white color, which is typical for domestic radio-transparent fairings).

Although there is no information about the airborne radar station used on the Berkut aircraft, indirectly about the potential capabilities of the radar complex of the fifth generation fighters, which can be created on the basis of the Su-47, can be judged by the information published in the open press about the new airborne radar, developed since 1992 by the "Phazotron" association for promising fighters. The station is designed to be placed in the nose of an aircraft of the "weight category" Su-35/47. It has a flat phased array antenna and operates in the X-band. According to NGO representatives, in order to expand the coverage area in the vertical and horizontal planes, it is planned to combine electronic and mechanical scanning, which will increase the field of view of the new radar by 600 in all directions. The detection range of air targets is 165-245 km (depending on their RCS). The station is capable of simultaneously tracking 24 targets, ensuring the simultaneous use of missile weapons against eight enemy aircraft.

"Berkut" can also be equipped with an optical location station located in the forward fuselage, in front of the pilot's canopy. As in the SU-33 and SU-35 fighters, the station fairing is shifted to the right so as not to limit the pilot's view. The presence of an optical location station, which probably includes television, thermal imaging and laser equipment, as well as a rear-view radar station, distinguishes the Russian car from the American analogue of the F-22A.

In accordance with the canons of stealth technology, most of the onboard armament of combat vehicles created on the basis of the Berkut will obviously be placed inside the airframe. In conditions when the aircraft will operate in airspace that does not have a powerful anti-aircraft missile cover and against an enemy that does not have modern fighters, it is permissible to increase the combat load by placing some of the weapons on external hardpoints.

By analogy with the Su-35 and Su-47, it can be assumed that the new multifunctional vehicle will carry ultra-long and long-range air-to-air missiles, in particular the UR, known as the KS-172 (this two-stage missile capable of developing hypersonic speed and equipped with a combined homing system, capable of neighing air targets at a distance of more than 400 km). The use of such missiles is likely to require external target designation.

However, the "main caliber" of a promising fighter, obviously, will be medium-range missile launchers of the RVV-AE type, which have an active final homing radar system and are optimized for placement in aircraft cargo compartments (it has a low aspect ratio wing and folding lattice rudders). NPO Vympel announced successful flight tests on the Su-27 aircraft of an improved version of this rocket, equipped with a haze ramjet engine (ramjet engine). The new modification has an increased range and speed.

As before, short-range air-to-air missiles should also play an important role in aircraft armament. At the MAKS-97 exhibition, a new rocket of this class, the K-74, was demonstrated, created on the basis of the UR R-73 and differing from the latter by an improved thermal homing system with a target capture angle increased from 80-900 to 1200. The use of a new thermal homing head (TGS) also made it possible to increase the maximum target destruction range by 30% (up to 40 km). Development of the K-74 began in the mid-1980s, and began flight tests in 1994. The rocket is currently ready for serial production.

In addition to creating an improved seeker for the UR K-74, NPO Vympel is working on a number of other short-range missiles, also equipped with an engine thrust vector control system.

Probably, the 30-mm GSh-301 cannon will also be retained as part of the onboard armament of promising fighters.

Like other domestic multifunctional aircraft - Su-30MKI, Su-35 and Su-47, the new aircraft, obviously, will also carry strike weapons - high-precision UR and KAV air-to-surface class for engaging ground and surface targets, as well as radar enemy.

The capabilities of the defensive system, which can be installed on a promising fighter, can be judged by the exhibits demonstrated at the MAKS-97 exhibition. In particular, the Aviakonversiya enterprise demonstrated a combined decoy target (KLC) for protection against missiles with radar, thermal and laser homing heads. Unlike the passive protection devices used on domestic and foreign combat aircraft, the KLC is effective in all wavelengths used in the homing heads of air-to-air and surface-to-air missiles. KLC is a combustion zone formed away from the protected aircraft due to the use of a directed stream of gases. A flammable liquid is introduced into the jet (in particular, it can be the fuel used by aircraft engines), sprayed to obtain a fuel-gas mixture, which is then ignited. Combustion is maintained for a predetermined length of time.

The thermal radiation of the combustion zone is a false target for ammunition with seeker, operating in the infrared range. The spectral composition of the burning cloud is identical to the spectral composition of the radiation of the protected object (the same fuel is used), which does not allow the TGS to distinguish a false target by spectral features, and finding a false target at a fixed distance from the real object does not allow the TGS to select it by trajectory features.

To protect against ammunition with a radar guidance system, plasma-forming additives are used in the KLC, leading to an increase in the reflection of radio waves from the combustion zone. Such additives form free electrons at the combustion temperature. When their concentration is high enough, the burning cloud reflects radio waves like a metal body.

For the laser wavelength range, finely dispersed powders of substances of the working bodies of lasers are used. In the process of burning, they either emit electromagnetic waves at the same frequency at which the target illumination laser works, or, without burning, are carried out of the combustion area and, during the cooling process, emit electromagnetic waves of the required range. The radiation power must correspond to the power of the signal reflected from the protected object when illuminated by the enemy's laser. It is regulated by the selection of substances added to the flammable liquid and their quantity.

In a number of publications, without reference to the sources, the characteristics of the new aircraft are published. If they correspond to reality, then "Berkut", as a whole, is in the "weight category" of the Su-27 fighter and its modified versions. Advanced aerodynamics and thrust vector control system should provide promising Su-47 followers with superiority in close maneuverable air combat over all existing or predicted potential adversaries. All other fighters, upon meeting with the Russian Berkut and the American Gravedigger Eagle, have a very modest chance of returning to their airfield. The laws of the arms race (which, of course, did not end after the "self-dissolution" of the USSR) are cruel.

At one time, the appearance of the battleship "Dreadnought" made all previously built battleships obsolete. History is repetitive.