Su-27 - answer of Russia to creation in USA of a fighter F-15 intended for a gain of domination in an air and having unique battle(dashing) possibilities. The journal “Interavia” has named Su-27 “ as the most capable fighter in the world ”. The beginning of the biography Su-27, machine of the fourth generation, is dramatic. Creating an equivalent F-15, the designer collective led by M. Simonov did not possess all completeness of datas about American F-15. When in the summer of a 1977 the
flight tests of a new plane(airplane) designated N-10 have begun was clarified: the tactical-characteristics of F-15 are higher, than it was supposed. And is significant.
Under the insisting the designers N-10 have sent in a museum of aircraft. The realization of the project of a new plane(airplane) - smaller began, than N-10, in sizes more accomplished on aerodynamics, arrangement, is valid capable to argue with F-15 for domination in an air. Later, by the way, the prototype SU-27 just at F-15 has selected a number of the important world(global) records. Su-27 (for stages N-10) was developed as the first domestic “unstablis” plane(airplane) with an electroremote control system. To pilot the machine to the pilot the electrocommand system with “ by brain centre ”, always by ready rational image helps to correct operations of the person, to correct an own error.
This system, expressing by language of the founders of the machine, is spreaded on volume of a plane(airplane) by the channels and extremely is hardy. Su-27 is excellent armed, far sees by locator. The machine is equipped with drives created in NPO “Saturn” of the name A. Lulka. AL-31F - first in country a two-contour drive of such class appropriate on parameters to maximum world(global) reachings. It(he) of a modular construction, with interchangeablis blocks, that simplifies and makes cheaper repair. The resource(safe life) of a drive is lifted up to resource(safe life) of a plane(airplane). The interest in West calls also two-place training-battle Su-27UB, as on “pair” a system of the weapon and management by him(it) completely is saved. Signifies, the battle(dashing) use of a fighter is possible and in such variant.Control system of arms: coherent the system of target destination is impulse - Doppler radar, optic-electronic helmet locator.
Su-27SK FIGHTER: HIGH POWER GUARANTEED
Formally, the development program of the Su-27SK fighter, a version of the Su-27 aircraft, was launched in 1969, though the conceptual studies and work substantiating its higher performance at Air Force research institutes and in industry date back to a much earlier period. Since then 30 years have elapsed and it would be interesting now to rate the machine from the viewpoint of the present-day standards, analyze the prospects for ideas which originated in the late 1960s and realized in the creation of the baseline aircraft and its version, the Su-27SK.The worldwide practise of developing air combat complexes favors the correct formulation of the concept of an air complex (AC) as an essential precondition for its "longevity." Thirty years is clear proof that the correct choice was made for the conception of the
Su-27 fighter. The main purpose behind the development was to gain air supremacy. In formulating the operational/tactical concept of the air complex, emphasis was placed on making the best use of its fighter qualities, while limiting the attack potential to unguided weapon systems.
This concept has retained its relevance despite the stress made on the attack potential in the new versions of fourth-generation fighters. In the opinion of military specialists, air complexes must be multirole, that is, they should be effective against ground targets while fully satisfying "fighter requirements." This becomes obvious from analyzing the concepts of such aircraft as F-22A, Rafale and others, which use both guided and unguided weapons for their ground target attacks.
However, the mere availability of the guided weapons, enabling highly accurate selective engagement of ground targets, is far from being sufficient for effective execution of attack missions. To withstand a serious counteraction of hostile ground-based air defense systems, it is necessary to enhance the fighter survivability (i. e. its ability to evade or withstand enemy attacks) by reducing its radar signature, increasing the composition and mass of combat survivability enhancement means, extending the frequency range and increasing the energy potential of the electronic countermeasures (ECM) equipment, assuring the low-altitude flying capability, etc. Moreover, to successfully achieve these and related ends, it would be effectual to have another crewmember aboard the aircraft to operate the search-and-attack systems. The necessity of meeting this condition is confirmed by both foreign and domestic practises (F/A-18E, Su-30MK, etc.). There is also information concerning plans to develop two-seat versions of the Rafale and EF-2000 aircraft. Implementing these measures usually results in degrading the air complex's fighter capacity, reducing its effectiveness in both short- and long-range air combats and virtually changing the fighter concept, turning it into a strike aircraft with an increased fighter potential.
The analysis of employment of aircraft in military conflicts taking place in the world for the last three decades shows that the task of gaining air supremacy has not become obsolete, rather it has grown significantly. Hence the concept of the Su-27 aircraft, whose performance characteristics have been optimized on the basis of the priority solution of this very task, still remains up-to-date. The effectiveness of the solution will depend on how the aircraft performance fits current demands, which, in turn, will depend on the engineering efficiency of the air complex and its systems.
The engineering efficiency is characterized by a number of criteria describing the degree of correspondence of the air complex to the level of combat aircraft development of the period under consideration.
Aerodynamics. Some aircraft experts maintain that perfect aerodynamics of an aircraft are directly linked to the beauty of its outlines. Apart from determining the shape of the airframe delighting laymen and specialists alike, the integral aerodynamic configuration with a lifting fuselage and developed root extensions guarantees a high level of aerodynamics. It is usually evaluated in terms of the maximum aerodynamic quality characterizing the potential of the aerodynamic configuration chosen for the newly developed aircraft and the maximum lift ratio setting the limit for its load-carrying capacity. In these respects the Su-27SK has no rivals in the world among the fourth-generation fighters and is only second to 10 - 15% of advanced fighters currently under development.
The realization of the longitudinal static instability at subsonic speeds, deflection of the leading edges and trailing edge high-lift hardware of the wing adaptively to the flight regime (in angle of attack and Mach number) reduce the trimming losses, increase aerodynamic quality, enhance the load-carrying capacity and decrease the induced drag during evolutions.
Design. The airframe of the Su-27SK fighter is rated at a maximum operational overload of +9g, which is close to the value of the pilot's physiological g-tolerance, and is unlikely to be exceeded in the nearest future. The airframe structure makes extensive use of titanium alloys and strengthened grades of steel. The relative mass of the structure is an indication of the structural cleanness of any aircraft and is equal to about 0.29 for the Su-27SK, which is on a par with the best world standards.
The Su-27SK has been designed to achieve the maximum possible level of combat survivability, that is the capability of an aircraft to proceed with the assigned mission after being hit by the enemy. The two-engine powerplant with independent fuel supply lines for each engine, three-spar wing, redundant aircraft control and hydraulic systems, protection of the pilot's cockpit with equipment units, and explosion-proof design of fuel tanks are just a few items in a long list of measures aimed at solving this problem.
Powerplant. The powerpant comprises two AL-31F double-flow turbojet engines developing a maximum reheat thrust of 12,500 kgf. The engine's specific thrust is 10% higher than that of its American counterpart, the F-100-PW-100. The AL-31F is the world's only series-produced engine for combat aircraft with the active control of the gap between the blades and casing of the turbine; this characteristic markedly increases the efficiency of the latter and fuel efficiency of the engine.
The feature that sets the engine apart is the high level of gas flow stability, which allows it to operate reliably under extreme conditions ranging from irregular air flow at the inlet to the air intake surge and assures safe flight at high angles of attack as well as when the aircraft slips into a spin.
In its design the AL-31F employs many unique engineering innovations determining the potential for increasing the thrust and service life. The realization of these novel ideas will extend its life well into the next two to three decades. An example of these innovations is a vectorable thrust engine.
Control system. The Su-27SK is equipped with an analog-type fly-by-wire system with a quadruple redundancy, assuring control of the longitudinally unstable aircraft. In the last few generations of fighters these have been phased out by digital systems. However, along with the undisputable advantages, the fly-by-wire systems have some disadvantages that prompted the designers to resume employment of analog systems as a backup or combine these to enhance reliability and quality of aircraft control. The Su-27SK aircraft is controlled by an automatic flight control system (AFCS) integrated with the navigation system and command guidance equipment. The AFCS stabilizes the angular position and altitude of the aircraft, levels it off, allows a programmed climb and descent, controls the aircraft in altitude, speed and heading as it is being vectored to air targets, returning to the home airfield, and making the landing approach. The novel concepts and technological solutions involved in the Su-27 enabled it to achieve a high flight performance which today allows it, even without modernizing its major systems, to meet the most stringent requirements placed on modern aircraft.
The integrated configuration with large wing extensions provides, apart from the high aerodynamic efficiency, agreeable conditions for operation of the powerplant at high angles of attack, markedly increases the interior spaces for fuel, which, in turn, makes it possible to achieve the unique flight range without carrying the drop tanks (1,400 km near the ground and 3,900 km at a high altitude in cruising flight conditions). The unique aerodynamic characteristics combined with the optimal choice of such aircraft parameters as the specific wing loading and thrust-to-weight ratio, plus employment of the fly-by-wire system, allow the Su-27SK to outmaneuver its foreign counterparts, including the new generation of European fighters. A stunt like the "Pugachev cobra" could only be reproduced by the American F-16 fighter after significant modifications.
Implementing promising developments in the Su-27SK is the precondition for its "longevity" and expediency of continuous modernization. Among the factors for allowing continuous improvement of the air complex performance characteristics through its modernization is a high level of the structural cleanness, which provides a reserve for installation of more sophisticated equipment and armament. This has been confirmed by experience gained in developing the latest versions of the Su-27 fighter.
Avionics. The avionics of the Su-27SK comprises an airborne radar, optronic fire control system, flight-navigation complex, ECM and communications facilities allowing the aircraft to perform its missions both during the day and at night, in all weathers and in the face of enemy ECM background. Compared to its main foreign counterpart, the F-15C "heavy" tactical fighter, the Su-27SK is on a par with the latter in avionics and surpasses it in composition and capability of the optronic fire control system. The Russian fighter's avionics offers an equal and, in some cases, better performance than similar European new-generation fighters.
The high effectiveness of the Su-27SK is largely due to its advanced weapon control system (WCS) assuring automatic all-aspect detection and tracking of air targets in a free space and against the earth background, engagement of the targets by its air-to-air missiles and gun fire from short and long distances, and destruction of ground targets by its unguided weapons.
The powerful airborne pulse-Doppler radar enables the aircraft to detect and simultaneously track up to ten air targets of the "tactical fighter" type at ranges of up to 120 km. The fighter is also armed with a state-of-the-art optronic fire control system comprising an infrared direction finder with a high-altitude effective range compared to that of the airborne radar, laser range finder, head-up display and helmet-mounted target designator sending virtually instant inputs into the missile homing heads as the pilot turns his head within a wide range of angles. The airborne radar operates in conjunction with the optronic fire control system to exchange the target designation data, which markedly improves the target detection probability and target tracking reliability, especially in enemy ECM environment. The WCS software enables the crew to identify air threats, classify each threat, and select the right weapon to destroy the air target that is the most dangerous in a given tactical situation.
The integrated navigation and communications systems, forming part of the avionics equipment, allow the aircraft to be navigated in all phases of its flight and landing approach in both automatic and director modes and provide radio communications with the ground control stations and other aircraft at distances of up to 1,500 km. The communications equipment is used for exchange of coded information during air combat as well as command guidance from the ground for intercepting air targets.
Armament. To attack air targets, the Su-27SK can carry up to six
R-27E medium-range air-to-air missiles with semi-active radar and infrared homing heads, up to six R-73E short-range combat missiles or various combinations of the same, on its ten hardpoints.
The R-27E missile can attack all types of air targets from short and long distances and in all weathers, from all directions and against the earth background, with the enemy using his ECM and maneuver capabilities. The missile intercepts air targets flying at speeds up to
3,500 km/h and altitudes ranging from 0.02 to 27 km. It is equipped with an inertial radio-updated navigation system and semi-active radar or infrared homing heads. A significant advantage of the Su-27SK armament complex is that it can simultaneously carry the R-27E missiles fitted with different types of homing heads, which enhance the effectiveness of execution of combat missions in the enemy ECM environment.
The R-27E missile is a short-range weapon allowing highly accurate head-on and tail-on attacks against air targets in air combat from all directions. By its effectiveness which derives from the performance characteristics (maximum g-load, target designation angle, angular rate of air target autotracking, minimum launching range for a maneuverable target), the missile outperforms the world's best analogs.
The aircraft also carries aerial bombs of up to 500 kg, including concrete-piercing bombs, clusters, unguided airborne rockets. Such a complement of attack weapons has been accepted largely for gaining air supremacy, and among the several ways to achieve this would be pinning enemy aviation down to the ground (destroying airfield components, dropping mines on them, destroying aircraft and ground installations, disrupting communication and control).
Thus, the avionics and armament of the Su-27SK fighter are presently used as the effective means of accomplishment of its main combat mission - gaining air supermacy through destruction of the enemy aviation both in the air and on the ground.
Operation. The maintainability characteristics of the Su-27SK and its operating performance are crucial for development of and especially promotion of Russian fighters on the combat aircraft world market. According to available evidence, the characteristics of the Su-27SK are on a par with those of foreign fourth-generation tactical fighters. However, in term of the strategy of operation, they are inferior. During their lifetime, the Russian fighters require a considerable amount of scheduled maintenance service and repairs.
Naturally, if a fighter designer does not expect his aircraft to take part in future combat, the additional expenses associated with preventive maintenance and various repairs are simply a waste of money. But if you presume that your aircraft will take part in combat operations, notably large-scale ones, then the availability of a streamlined overhaul facility and well-trained maintenance personnel will not be regarded as a burden incurring additional expenses, but an advantage, since establishing an overhaul facility network usually takes considerable time which may be short during a war.
Effectiveness. Normally,what is meant by the combat effectiveness is the degree of fitness of an aircraft for successfully completing assigned missions. As stated above, the main mission of the Su-27SK is to gain air supremacy.
From the viewpoint of striking distance, the Su-27SK fighter, noted for its unique "load - range" performance, is on a par with the world's best. Interacting with ground and air control stations, the fighter can fly missions involving the interception of air targets to their full operational depth. The long flight range of the aircraft also enables rapid concentration of fighter aviation efforts in the most dangerous directions and its employment where airfields are rare and communications poor.
The conclusive phase of any fighter mission is the air combat, the results of which are used for appraising the effectiveness of the fighter. The equipment and armament of the Su-27SK, meeting the world's best standards or surpassing them, allow the aircraft to boast an appropriate effectiveness in long-range air combat. According to various estimates, the Su-27SK is in no way inferior to its foreign analog, the F-15C. Concerning short-range air combat, the Su-27SK with its unsurpassed agility, unique target designation system and armament, R-73E missiles, not only outperforms all current foreign counterparts, but will be second to none among the promising new-generation fighters.
The overall evaluation of combat effectiveness of the Su-27SK compared to its foreign counterparts, averaged over a great number of combat missions and conditions for their fulfillment, indicates that it outperforms the F-15C tactical fighter in combat potential factor by approx. 10 percent.
From a brief analysis one concludes that, by its concept, engineering perfection and combat effectiveness, the Russian Su-27SK fighter fully meets the requirements placed on the fighters of the early 21st century. The unique flight performance and significant reserves for further modernization of avionics and armament provide the obvious preconditions for operating the aircraft for decades to come.
Thus, a growing interest in the fighter may be anticipated in the countries planning to modernize or expand their aircraft fleet. Thanks to its design features, the Su-27SK can be customized by modernizing the armament systems (adding air-to-surface guided weapons), increasing the flight range through mid-air refueling as well as installing equipment at customer's request. This "flexibility" will make it possible to increase the export potential of the Su-27SK turning it into one of the best selling aircraft in the world.
Max. military load (kg):
min. indicated speed: 200
Acceleration time at H=1000 (sec):
from speed 600 to 1100: 14.1
from 1100 to 1300: 9.8
14,7 x 21,9 x 5,9
Service seiling (m):
2 twin shaft DTRD- AL31-F2, 2 x 13'600 kgs
4 AA R-27 (R-27R, R-27T, R-27TE)
6 AA R-73
30 mm DP GSh-301
RBK cluster bombs (25, 500 kg)
retarded aerial bombs (100, 250, 500 kg)
unguided aerial missiles (C-8, C-25)
countermeas.: pilot illum.radar warning receiver (bearing data host.radar emissions, chaff and infra red decoy dispensers, active multirole jammer)
- optronic infra-red search and track sensor, laser range finder(40 -100 km range)
- jam-proof coherent pulse Doppler radar, Phazatron N001 Zhuk, with track-while-scan and look-down/shoot-down capability (range: target 3sq.m - 40/100 km; search, detect and track up to 10 targets with automatic threat assesment and prioritization)
automatic flight controls