F-22 Raptor – the first operational 5th generation fighter.
Su-35 – the most capable Russian multirole combat airplane, based on Su-27. Solutions that were tested on Su-37 – technological demonstrator, were later transferred on Su-35 as well.
Eurofighter Typhoon – the most potent European multirole combat airplane today. Realized through smart approach of unifying potentials of more European aviation industries.
Although it could be initially concluded that we are going to deal with pure fighter airplanes, this would be only partially correct. The most modern combat airplanes which rule the skies today, although their primary task is the realization of air supremacy, they also have secondary tasks of attacking the ground and sea surface targets, as well as surveillance and electronic warfare in case of need; these are true multirole combat machines. Most of them were conceptually conceived during the Cold War days, operationally introduced in 1980s and 1990s (later upgraded) or in 21st century. In this segment as well, the USA leads the way with their only 5th generation fighter, the famous F-22. After the end of the Cold War the Russians developed their most modern multirole combat airplanes based on excellent Su-27, with Sukhoi test and design bureau playing the leading role in designing of contemporary and future top Russian fighters. The Russians, apropos Sukhoi, are developing their own 5th true generation fighter. Still, the Russian fighter has to go finish extensive testing before entering service. And even then, when it entered service, the Americans will operationally use their F-22 for more than a decade, which is long enough to learn many new operational tricks and lessons for improvements.
Europe chose a more conventional approach. Its newest fighters cannot be classified as 5th generation; they are more, as often qualified, 4+ generation. One more fact which can illustrate the technical advantage of USA over Europe is that F-22 was banned from sale to other countries and most important F-22 technical data are classified as top secret. On the other hand, top European fighters are aggressively marketed and offered for sale worldwide.
There are certain characteristics that every 5th generation fighter needs to have. Next to state-of-the-art avionics and weapon systems, there are characteristics like super-maneuverability (usually accomplished through vectored thrust), supercruise, and of course stealth features. The US Air Force F-22 is the first, and for the moment the only true 5th generation fighter in operational service. The superiority of US fighter industry is well described with the fact that once F-22 was deployed within the US Air Force in 2005, it stood next to F-15 which was anyway one of the best fighters and interceptors in the World. Although designed primarily as air dominance and superior fighter, F-22 is like all other modern fighters, a true multirole combat airplane, capable for strike, surveillance and even AWACS operations.
Already at first glance it is clearly visible that during designing of F-22 special attention was devoted to its low radar signature. In all three projections the intention was to put the majority of the edges parallel to each other, in order to reflect the majority of radar electromagnetic radiation away from the radar receiver of enemy air defense, rather than reflecting it back to the receiver. This is a principle described before. Air intercept missiles as well as other weapons were carried internally, inside three weapon bays. Classic carrying of weapons suspended under the wing and fuselage hard-points over pylons would be in collision with stealth philosophy. On F-22 missile launches require the bay doors to be open for less than a second, during which the hydraulic arms push missiles clear of the aircraft. In addition to lowering RCS of an airplane, the internal carrying of weapons also significantly decreases the aerodynamic drag of airframe; consequently lowering fuel consumption as well. These and other design characteristics (like the use of RAM coating) have lowered RCS of F-22 to the size of a bird in the sky.
Two Pratt & Whitney F119-PW-100 turbofan engines, each rated at 16 tons of static thrust, do not offer just raw power, but also vectored thrust. Vectored thrust is realized through both nozzles, movable up and down by 20°. Through the vectored thrust, fighters like F-22 are gaining supermaneuverability – a term closely related to 5th generation fighters. To understand the importance of vectored thrust, we need to know that conventional turbojet/turbofan powerplants have fixed nozzle at their ends. Through the fixed nozzle, the rearward escaping jet stream generated by the engine is directed in parallel, or very close to parallel, with longitudinal airplane axis. This way, momentums that turn the airplane around its center of gravity are generated only by the aerodynamic forces created by deflection of control surfaces. The airplanes which have thrust vector control (TVC); vector of thrust force can be changed (depending on the nozzle deflection angle) for the certain amount of degrees from the longitudinal axis of the airplane; thus vectored thrust force consists of component parallel to longitudinal axis of the airplane, and the component which is perpendicular to that same axis. This component perpendicular to the axis of the airplane creates additional momentum around airplane center of gravity. The end result is that the airplanes with vectored thrust are capable of flying under much higher angles of attack and their maneuverability is greatly enhanced, compared to airplanes with non-vectored thrust. Vectored thrust enables an airplane to execute maneuvers with much higher rate of turn and in smaller volume of space. F-22 can perform easily maneuvers like Pugachev cobra or Kulbit – maneuvers that were inaugurated by the Soviet MiG-29 and Su-27 and later perfected by Su-37.
In the range of F-22 outstanding characteristics, there is also, the so-called supercruising. Supercruising describes the capability of a fighter to cruise at the supersonic flight speed without the need to use the afterburner. F-22 supercruise flight speed reaches Mach 1.8. Supercruise is important because it enables an airplane a great range while flying supersonic (no exaggerated fuel consumption for supersonic flight with afterburner).
There is a huge step forward accomplished with F-22, compared to F-117. Although both airplanes are designated with letter “F”, common for US originated fighters and interceptors, F-117 was actually pure strike airplane built around its stealth. F-22 is also stealth, but unlike F-117 it has onboard radar and powerplants with afterburners and is capable of launching attacks against both ground and aerial targets. Hence, operational capabilities of F-22 are surpassingly greater than those of F-117. Onboard radar on every fighter is a means for detection and location of enemy’s presence; at the same time it can uncover the presence of its own platform (fighter). For that reason F-22 radar is adapted in a way to avoid uncovering of its F-22 platform; all in favor of stealth philosophy. Radar onboard F-22 tracks an enemy target with its focused electromagnetic radiation of only 2° in azimuth and only 2° in elevation. With such a focused energy the radar avoids wide angles of its radiation. Also, using focused radar energy, F-22 can launch a kind of electronic attack, overloading enemy sensors.
It was mentioned already that the Russians developed their range of most capable fighters on the basis of everlasting Su-27. There are also top of the class fighters based on MiG-29; however, the Russians gave the advantage to Sukhoi test and design office to be the main carrier of their best fighters development. Su-37 attracted special attention at the end of 1990s. Although it was actually a technological demonstrator that never entered serial production, the technologies that were used on Su-37 were later transferred to the most advanced Russian combat airplanes. Su-37 embodied the newest achievements of Russian fighter/interceptor industry of 20th century.
The maiden flight of Su-37 was in April, 1996, piloted by Yevgeny Frolov – one of the best Russian pilots at the time. Five months later followed the demonstration flight at the famous Farnborough ’96 exhibition, where it astounded the spectators performing unimaginable air maneuvers with the help of vectored thrust. “Super Cobra” was one of such maneuvers, demonstrated publicly for the first time. In this maneuver the airplane enters flying horizontally, at the flight speed of around 400 km/h. Then the angle of attack is increased to 135°, followed by decrease of angle of attack to 90° and continuous horizontal flight in that position for 4 – 6 seconds, using thrust vector control. The airplane finishes the maneuver by dropping the nose and continues horizontal flight at the flight speed of some 150 km/h. Complete Super Cobra maneuver should be performed without loss of altitude. Another even more impressive maneuver from the Su-37 repertoire was “Kulbit” (somersault), also known as the “Frolov chakra”. The airplane enters this maneuver flying horizontally at the speed of 350 km/h and then increases the angle of attack till 180° (actually flying in reverse for a moment on its back), followed by finishing 360° tight turn around airplane’s perpendicular axis with the use of vectored thrust. The airplane finishes the maneuver in 30° nose-down position and the speed of 60 km/h. Su-37 was the first airplane that performed “Kulbit maneuver”. It is clear that both “Super Cobra” and “Kulbit” maneuver couldn’t be performed without vectored thrust.
Su-37 powerplant consisted of two AL-31FU experimental turbofan engines with 3D thrust vectoring nozzles; each engine with more than 14,000 kilos of static thrust with the use of afterburner. Thrust vectoring nozzles are attached to the airframe over ring joints and are 15° movable up and down. Depending on the maneuver the nozzles can be moved in the same direction (during pitch), or differentially – meaning one up and one down (during roll).
Aerodynamically unstable configuration with installed fly-by-wire system in combination with low wing loading and high thrust-to-weight ratio, together with integrated control system with thrust vector control, insures for the Su-37 super-maneuverability – one of the key 5th generation fighter features.
Under its twelve hard-points Su-37 could carry a wide range of the Russian most advanced weapons for engaging both aerial and ground targets. For close air combat, next to the installed cannon, it could use short range R-73M heat-seeking missiles with the range from 300 meters to 30 kilometers. This missile is one of the World’s most capable ones; thanks to its 3D thrust vectoring nozzle it can perform turns at highest angular speeds. Its wider seeker angle (to 60° off-boresight) and improved infrared counter-counter-measures makes it even deadlier. For medium range engagements Su-37 could use the newest versions of infrared or radar homing R-27 or R-77 missiles; with the range of up to 150 kilometers. Against very distant aerial targets Su-37 could use Ks-172 with declared range of 400 kilometers. This is six meters long active radar homing missile with “Fire and forget” characteristic.
In its efforts to design the most advanced fighter airplane Europe followed similar approach as in case of A380 airliner. Germany, Great Britain, Italy and Spain unified the potentials of their aviation industries and brought to the light the Eurofighter – advanced 4th generation fighter. Eurofighter is an outstanding airplane, but still conventional fighter of classic design. Delta-winged configuration, without horizontal tail surfaces is completed with frontal control canards. It looks as if the basic Eurofighter design was under strong influence of traditional French fighter design, which relied heavily on delta-winged configuration in the past. In general, the newest European fighter designs follow the delta-winged configuration; next to Eurofighter, Swedish Gripen and French Rafale are also delta-winged. The French were also included in the European consortium for Eurofighter development, but later the French pulled back and continued to develop its own fighter named Rafale. Rafale was developed as well in a naval variant destined for aircraft carrier operations.
Considering the maneuverability of Eurofighter, it is much better compared to the most agile Cold War era predominant fighters like F-16, MiG-29, Su-27 or Mirage 2000, but still it is not on the level of F-22 or Su-37. Lack of thrust vector control on Eurofighter is the reason why it cannot compete in maneuverability with these two outstanding sky performers. To achieve adequate maneuverability on Eurofighter, its designers reached for traditional tools known from before – unstable aerodynamic configuration with computer-assisted flight control; add to this the frontal control canard surfaces. Canard configuration with delta wings was recognized even before as a very potent configuration, compared to classic configuration with horizontal and vertical tail surfaces. Therefore, Eurofighter maneuverability is at an excellent level. The powerplant of Eurofighter consists of two turbofan Eurojet EJ200 engines (each rated at more than nine tons of static thrust in afterburning regime), powerful enough to overcome excessive aerodynamic drag inevitable during sharp maneuvering. Engines installed inside Eurofighter, in fighter configuration, give it thrust-to-weight ratio of more than 1 – meaning that thrust force delivered by the engines is greater than the weight of the airplane. For airspace scanning Eurofighter can rely, besides on its radar, on its passive IRST – Infra-Red Search and Track. IRST detects objects in the air by sensing their heat emission and heat signature. The advantage of IRST over classic radar is that IRST is a passive system which does not emit any sort of detectable energy. The classic radar for example emits electromagnetic energy to detect aerial targets; however, this electromagnetic energy can be sensed by radar warning receivers of detected airplanes. Anyway, IRST system is not a new item on the list of fighter accessories; for the tactics of obscure approach and attack against aerial targets it was extensively used by the Soviet MiG-29 and Su-27 fighters and interceptors. Modern IRST systems, compared to those from 1980s, are much more sensitive, have better resolution and greater range, so they are used onboard many most advanced fighters worldwide.
Considering some other characteristics which are “in vogue” today among fighters, Eurofighter is capable of supercruise, although its supercruise flight speed is lower than the one of F-22.
Although during the design phase of Eurofighter some standard methods were used to lower its radar cross-section, Eurofighter cannot be classified as a true stealth airplane.
Taking everything into account, Eurofighter is an excellent fighter airplane. Blending the newest technical aeronautical achievements with tradition, gave us a fine all-around combat airplane. The proof that Eurofighter can cope even with the best of the best came after the Red Flag 2012 military drill held in the Alaskan airspace. On that occasion, under the canopies of two Eurofighters that participated in the drill, appeared four F-22 markings. In good tradition of the best fighters in the history of fighter aviation, these markings designated that the mentioned two Eurofighters shot down four F-22s; of course, in a simulated air battle, without live firing of air-to-air missiles. Still, this is valid information that undoubtedly indicates that the Eurofighter can deal with anything that flies the skies today.
When considering the best European fighters of these days, for sure, the Swedish Gripen and French Rafale need to be taken into consideration. Both fighters, like Eurofighter, incorporate aerodynamically unstable delta winged configuration augmented with control canards.
The best contemporary fighter airplanes, just as their most dominant predecessors through the history of aviation, serve to the pride and honor of their air forces and the countries that designed and built them. As always, fighters represent technically the state-of-the-art and crème de la crème among all the aircraft. The most complex and lethal systems are built in these flying machines. To their pilots they provide good feeling of aerial superiority which they have to assure. Without doubt, the fighter airplanes will represent in the future, as well as before, the sole pinnacle of combat aviation. What is to be changed is that in the nearer or further future they will become unmanned.
