They have one sky for two. One way and one task - to sweep the enemy aircraft from the skies. They are air superiority fighters. Winged combat vehicles from the "first line", the elite of modern combat aviation. Their complexity is prohibitive, and the possibilities are endless. They have too many advantages, but no disadvantages. They are strong and beautiful in their inexhaustible celestial fury. Eternal rivals - Su-27 and F-15.
Who are you, funny cowboy?
His birth is associated with the Vietnam War. The results of meetings with Soviet MiGs demanded a change in the entire previous paradigm of the development of American fighter aircraft. The Air Force urgently needed a highly maneuverable "MiG killer", equally effective both in close air combat and at medium and long distances. Outstanding electronic "stuffing" must be enclosed in an equally perfect shell. American designers boldly took a step towards the new, fourth generation of fighters.
The first flight of the Eagle took place in 1972. Four years later, the F-15 Eagle was put into service. To date, these legendary aerial fighters have won 104 aerial victories - without a single defeat! "Unbreakable" angels of death, who can only be defeated with American weapons. "Eagle" was shot down only once - in 1995, during a Japanese Air Force exercise, an F-15 was shot by mistake by a similar F-15.
In the official reports on the results of the combat use of the "Eagle", other tales are also described. According to the Yankees themselves, the level of control of Iraqi airspace during the Gulf War "had no historical precedent." A similar thing happened eight years later - the "Eagles" tightly closed the sky over the Balkans.
But why among the dozens of Eagle trophies there is not a single aircraft equal to it in terms of power? Not a single Eurofighter Typhoon or Dassault Raphael?
The most notable trophies are nine light MiG-29s in a simplified export version. All other victories of the F-15 were won over the obviously outdated aircraft of the second or third generations: the French Mirage F-1, Soviet Su-22 (export modifications of the Su-17), MiG-21, MiG-23, MiG-25 …
Why do Americans always fight the previous generation of aircraft? Is there some terrible secret connected with this? This needs to be dealt with.
And now the main competitor of "Eagle" has arrived. Meet, gentlemen - the Su-27 fourth generation multipurpose highly maneuverable fighter.
Who are you, mysterious Russian warrior?
A daring response to the West at the end of the Cold War.
At the turn of the 70s and 80s, an aviation masterpiece was created in our country, designed to outshine the American Eagle. The idea was completely successful: the domestic 4th generation fighter set new standards in the field of combat aviation.
The design team of the Sukhoi Design Bureau managed to find a number of interesting solutions related to the layout and aerodynamics of the future aircraft.
The pretentious silhouette of the Su-27 is unlike any of the foreign fighters. The graceful bend of the nose of the fuselage, a smooth transition to the wing, protruding engine nacelles - all this is a consequence integral layout aircraft, in which the lift is formed not only by the wing planes, but also due to the special shape of the fuselage!
A huge contribution was made by aerodynamic experts - true geniuses of their craft. As a result, despite the similar value of the wing load (≈300 kg / sq.m), the lift coefficient of "Sushka" is one and a half times higher than that of the American "Eagle", and the maximum aerodynamic quality (the ratio of lift to frontal resistance) reached 12 units (such values are found only in passenger airliners). Extremely volatile design!
The world's most advanced aerodynamic design allowed to create a larger and heavier fighter. The Su-27, in comparison with the Eagle, had an increased internal fuel supply, a longer flight range was provided and the bulkiness of the domestic electronic equipment was leveled (Soviet microcircuits are the largest microcircuits in the world!). The elastic "hand" of aerodynamic force was powerfully pulling the Su-27 up, despite the large take-off weight of the domestic aircraft.
The brave representative of the family - Su-35
Engineers tried a lot, creating a mighty "heart" for a magnificent glider. The AL-31F family of turbojet bypass aircraft engines with 13 tons afterburner thrust! High thrust-to-weight ratio (≥ 1) is the key to super-maneuverability and vigorous vertical maneuvers.
In terms of the established rate of climb, the Su-27 has no equal in the world (over 300 m / s).
And our partners from China still cannot copy the heat-resistant blades of the AL-31F turbine with labyrinths of internal cavities through which cooling air passes. Apparently, their design turned out to be more complicated than Swiss watches and Japanese electronics.
Finally, something that cannot be seen with the naked eye. The degree of longitudinal static stability of the Su-27 is negative and amounts to 5% of the average aerodynamic wing chord (MAP). Of course, we are talking about flying at subsonic speeds.
What does this situation mean?
Longitudinal static stability in angle of attack is the ability of an aircraft to independently maintain a given angle of attack α and return to the initial value α in the event of a random deflection under the influence of disturbing forces.
Stability is a nice thing in a straight flight, but a fighter needs high maneuverability. The higher the stability (measured in% MAR), the greater the balancing loss, the worse the controllability and driving dynamics. To perform any maneuver, you will need to apply a larger control torque by deflecting the control surfaces at a larger angle. Great effort, extra fractions of a second of precious time in battle.
The stability of a flying aircraft is determined by the position of the aerodynamic focus (the point of increase in lift with a change in the angle of attack) relative to the aircraft's center of gravity. The Su-27 fighter was designed in such a way that its aerodynamic focus is located in front of the CG. Every second the plane is ready to raise its nose and "somersault" back through the tail. Without any pilot's involvement. It is statically unstable.
This makes the Dryer a surprisingly nimble machine, but negative stability conflicts with handling requirements. The fly-by-wire control system helps (the Su-27 was the first of the domestic combat aircraft to be equipped with an EDSU). The computer memory contains the correct coefficients of control forces for each of the flight modes - otherwise, a person would not be able to control the Su-27.
A reasonable question is what happens if the EDSU fails? Despite the Sushka's inadequate response to the control stick movement, an experienced pilot will most likely be able to reach the airfield and land the plane. Static instability of 5% MAR is still tolerable.
But another representative of the "twenty-seventh" family, the Su-35, in case of failure of the EDSU, will write out a couple of somersaults and break for sure. The degree of its static instability has been brought to 20% of the MAR - manual control of the aircraft is excluded. However, the risk of such a situation is negligible - the ESDU of the Su-35 aircraft is made with four (!) Redundancy in the longitudinal channel and three times in the lateral movement channel.
Integral layout, powerful engines, amazingly beautiful and efficient aerodynamic design, static instability … Next - the Shchel-ZUM helmet-mounted target designation system, the unique Pugachev Cobra combat technique, RVV-AE air-to-air missiles. After getting acquainted with such facts, the dispute “F-15 vs. Su-27 loses its meaning. The domestic fighter is much stronger and more perfect than its American counterpart.
YOUR OWN PEOPLE?
When it was announced that the McDonnell Douglas had won, the Sukhovites breathed a sigh of relief: the Su-27's layout looked much more promising. True, there were fears that the Americans, through the open press, slipped "misinformation" to their overseas colleagues, while they themselves were making a completely different plane. However, after the official demonstration in 1972 of the prototype "Needle", these fears dissipated: it became clear that the specialists of "McDonnell Douglas" took the simplest and cheapest, but far from the most promising path. As the head of the project department of the OKB Sukhoi O. S. recalls. Samoilovich, after takeoff of the YF-15, the head of TsAGI G. P. Svishchev said to Sukhoi: “Pavel Osipovich! Our lag has become our advantage. The plane took off, and we know what it is …"
- From the history of the creation of the Su-27 fighter.
Su-30, F-15C and Mirage-2000
The division of fighters into generations is largely arbitrary. Different weight categories, different levels of technological performance, different purposes. It happened that within the framework of one generation, the 8-ton MiG-21 and the 18-ton Phantom got along in a strange way (moreover, the former relied on close air combat with the use of cannon armament, and the latter relied on its own superradar and medium-range missile defense system). They were united only by the fact that the concept of both turned out to be, on the whole, erroneous.
Often, machines belong to the same generation, between the creation of which there is a whole temporary and technological gap. It is believed that the first fighter of the fourth generation was the American carrier-based interceptor F-14 "Tomcat" (first flight - 1970, entered service - 1974). It looked good against the background of the Phantoms, but after a couple of years it was hopelessly outdated - in fact, it had no noticeable advantages over the F-15, but absolutely lost to the Eagle in close maneuvering combat. Result: Eagles continue to fly to this day, and the last Tomcat was decommissioned eight years ago.
Finally, modernization. Like an old joke about craftsmen that they upgraded a TV set for a whole year and then sold it like a vacuum cleaner - how can you compare the first serial Su-27s of the early 80s with modern Su-35 fighters? How many pluses do you need to put after the number "4" to fit these machines within one generation?
The problem is simpler - how similar are the F-15C of the 1980 model and the modernized F-15C of the early XXI century? A new version of the AN / APG-63 (V) 2 radar with an active phased array, new long-range missiles AIM-120 AMRAAM, new digital electronics - yes, this is actually a different aircraft with completely different capabilities!
In order not to delve into this interesting, but endless dispute, one can limit ourselves to one obvious conclusion: the fourth generation of fighters really exists as a collection of some general ideas. Key development trends are versatility, high maneuverability, high-quality and expensive avionics. Nevertheless, it is worth recognizing that the era of the fourth generation stretched for more than 40 years - the aircraft of the "early period" were radically different from those that were created later.
Actually, this is the main difference between the F-15 and the Su-27, which the authors of analytical articles devoted to these heroes rarely pay attention to - the Eagle is at least 10 years older than the Sukhoi! As can be seen from the excerpt from the history of the creation of the Su-27 quoted above, when the first F-15 took off, our fighter had not yet left the stage of sketches.
It is often stated that the Su-27 made its first flight on May 20, 1977, just five years later than the Eagle. But this is slyness - that day a prototype T-10-1 took off, which had little to do with what we call the Su-27. Due to the inconsistency of the characteristics of the prototype with the specified values, it was decided to completely redesign the aircraft: the wing profile and the shape of the fuselage were changed. The wing area has increased from 59 to 62 meters. Ailerons and flaps gave way to flaperons. The brake flap has moved from the lower surface of the fuselage to the upper surface, located behind the cockpit canopy. The cockpit canopy itself has changed, the layout of the rear of the aircraft has changed, new suspension assemblies have appeared …
The new prototype of the fighter received the designation T-10C - according to the figurative expression of the chief designer M. P. Simonov, only the tires of the wheels of the main landing gear and the ejection seat of the pilot were preserved from the T-10-1.
The first flight of the T-10S was in April 1981. At this time, the American F-15 was already fully exported and used in hostilities in the Middle East.
The first batch of production Su-27 fighters was produced in 1984. The first combat unit to receive the Su-27 was the 60th IAP at the Dzemgi airfield (Far Eastern VO) - its pilots started mastering the newest aircraft in 1985.
By 1987, the main elements of the Su-27 aviation complex were fully formed - the N001 Mech airborne radar was "brought up" and the R-27 and R-73 missiles were adopted. In combat units, a training pair of Su-27UB appeared, which accelerated and simplified the training of personnel. At about the same time, regular "meetings" of the Su-27 began with the planes of a potential enemy - a sensational collision over the Barents Sea with the Norion reconnaissance "Orion" of the Norwegian Air Force, a dangerous rapprochement with American fighters during the exercise "Tim Spirit" (Far East), etc. etc.
Finally, a pure formality - after successfully passing all the tests, by the Decree of the Council of Ministers of the USSR dated August 23, 1990, the Su-27 was officially adopted by the Air Force and Air Defense Aviation of the Soviet Union.
Epilogue
The harsh truth is that by the time the Su-27 appeared, the American Eagle was already noticeably outdated.
The designers of McDonnell-Douglas were ahead of their time, having built in 1976 a superfighter that had no worthy opponents for 10 years. This explains the large number of second and third generation fighters shot down by the Eagles.
MiG-23 (start of operation - 1969, modification of the MiG-23ML - 1974), MiG-25 (start of operation - 1970) … The F-15 crumbled all its peers.
The balance of power in the air changed only with the advent of the Su-27.
The F-15D, trying to chase the Su-27, lost sight of it and desperately asked the observer: "Where is Flanker?" (Flanker is the NATO code name for the Su-27). “He's behind you,” the wingman replied. The described "air battle" did not receive any coverage in the Western press.
- Visit of the Su-27 to the Langley airbase. USA, 1992.
Years fly by, epochs change … Two years earlier, the events described at Langley airbase, the YF-22, a prototype of the fifth generation American fighter, took to the air. Around the same time, TsAGI defended the draft design and model of the aircraft, which received the designation MFI (multifunctional front-line fighter). The following features of a promising fighter were voiced: "stealth", "super-maneuverability", "non-afterburner supersonic" and other very familiar terms.
What came out of all this is already a topic for another story.
