A number of important requirements are imposed on modern and promising fighters of the 5th generation. In particular, they address issues of stealth and detection systems. A modern fighter must spot and attack the enemy long before it is spotted. In this context, one can consider the advanced fighters of the leading countries - the American F-22A and the Russian Su-57.
American supremacy
In advertising materials for the Lockheed Martin F-22A project, numerous advantages of this aircraft over other aviation technology are constantly mentioned, due to which complete superiority is ensured. Let's take a look at the arguments behind this ad.
The modern ideology of the development of US tactical aviation provides for the maximum reduction in the aircraft's visibility through the use of the so-called. stealth technology. The F-22A has special contours and airframe design, special nozzles, etc. Due to this, it is said, it was possible to drastically reduce the effective scattering area and thermal radiation - reducing the visibility for radar and infrared detection means.
The exact values of the RCS and other parameters, for obvious reasons, are not published, but there are different estimates. The version about EPR at the level of 0.3 sq.m. is popular among Russian researchers. In foreign sources based on the materials of "Lockheed-Martin", it is indicated that at some angles the EPR drops to 1-2 sq. Cm. It should be remembered that the actual value of such a parameter may depend on a number of factors. In addition, in certain situations, the aircraft can be retrofitted with reflectors that mask its real characteristics.
Measures have been taken to reduce heat radiation. First of all, these are special flat engine nozzles that reduce the temperature of the exhaust gases. During high-speed flight, the leading edges of the airframe are heated. In this case, a special cooling system is provided. The exact parameters of infrared radiation are unknown, but a number of sources claim that the aircraft is maximally protected from IKGSN missiles.
The main detection tool on the F-22A aircraft is the Northrop Grumman / Raytheon AN / APG-77 airborne radar. The station with AFAR has an instrumental range of more than 520 km. The detection distance depends on the parameters of a specific target. Large targets with a large RCS are detected at a distance of 400 km. With EPR of 1 square meter, the range drops to 220-240 km, with 0.1 square meter - 110-120 km. The station accompanies 100 targets and provides fire for 20.
The radar is supplemented by the ALR-94 radiation warning system (IRS), capable of picking up radar signals at ranges of more than 400-450 km.
Curiously, the AN / APG-77 radar also contributes to the aircraft's stealth. It has an LPI (Low Probability of Intercept) mode of operation with a special configuration of the emitted signals. It is argued that the reactive missile defense of an enemy aircraft cannot correctly identify such radiation and warn the pilot of the threat.
Russian advantages
It is known that in the Russian project of the Su-57, various solutions were actively used to reduce the signature in all main ranges. At the same time, the results of such measures, as in the case of the F-22A, are classified. Even the main characteristics of this kind were not disclosed, which is why so far we have to deal exclusively with estimates of varying degrees of plausibility.
Due to the design and shape of the airframe, the EPR of the Russian aircraft, according to various sources, ranges from 0.1 to 1 sq. M. Earlier, foreign publications mentioned EPR up to 2-3 sq. M, which does not look plausible. Apparently, the issues of aircraft stealth were solved in such a way that the smallest RCS is observed when irradiated from the front hemisphere, i.e. when approaching the enemy.
Unlike the F-22A, the Russian Su-57 has circular engine nozzles with a fully controlled thrust vector. It is assumed that this does not allow reducing thermal radiation, but there is no exact information on this. There is information on measures to reduce the temperature of reactive gases and, as a consequence, to reduce the visibility for IKGSN.
The Su-57 is equipped with an N036 "Belka" radar with several AFARs located in different parts of the airframe. Used "traditional" nose antenna, as well as devices in the leading edge and wingtips, operating in different ranges. Due to this, all-round visibility is provided at ranges of up to hundreds of kilometers, allowing timely notice of air targets.
According to known data, "Belka" detects objects with EPR of the order of 3 square meters at ranges of 400 km. For EPR = 1 sq. M, this parameter is reduced to 300 km. From a distance of 165 km, a target is detected with an RCS of 0.1 sq. M. Other parameters of the radar are unknown.
Unlike the F-22A, the Su-57 has an optical radar station. The OLS-50M product is capable of finding targets by their thermal radiation at distances of tens of kilometers. At the same time, the aircraft does not unmask itself by the radiation of its radar. The optical location station is included in the sighting and navigation complex and can provide data for firing.
Hide and find
The available data on the characteristics of the equipment and its units suggest that the American F-22A fighter, in ideal conditions, is able to detect the radio signals of the Russian Su-57 at distances of more than 400 km. However, the detection and tracking of the AN / APG-77 airborne radar is possible only at shorter distances - on the order of 110-120 km with a collision course. At the same time, the F-22A will already be able to launch long-range missiles.
In similar conditions, the potential of the Su-57 is at least not lower. The exact parameters of its electronic intelligence systems are unclear, but it can be assumed that it is possible to detect foreign signals at distances of hundreds of kilometers. Further, the question of distances depends on the real characteristics of the potential enemy's equipment.
If the assessments of Russian experts are correct, and the RCS of the F-22A fighter can really reach 0.3 square meters, then the N036 radar will notice it from a distance of at least 160-200 km. However, it is impossible to completely exclude the possibility of reducing the RCS to 1-2 sq. Cm in some conditions. In this case, the detection and tracking range can be sharply reduced. One should take into account the fact that the "Protein" contains several modules of different ranges, complementing each other. Situations are quite possible when one AFAR will be able to notice the target earlier than the other and provide the maximum possible detection range.
In certain situations, the Su-57 may have an advantage over the F-22A due to the presence of an OLS. However, in terms of range, such a system does not exceed the main radar and therefore is, rather, an additional means of detection.
Who will win?
As you can see, the leading countries used in their advanced projects all the basic ideas and solutions related to issues of visibility and detection. It is assumed that due to this, the Su-57 and F-22A will be able to remain unnoticed for as long as possible, but timely detect the enemy and be the first to carry out a missile attack.
Available data show that both aircraft have certain advantages over each other, capable of influencing the outcome of the battle at any time. However, the results of the battle are determined not only by issues of stealth and detection systems. The characteristics of weapons, communications and command and control systems, the level of training of pilots, etc. can become important or even decisive factors.
However, the presence of such factors does not diminish the importance of the aircraft's own characteristics. And in this respect, as we can see, the Su-57 and F-22A are advanced designs with high parameters and wide capabilities.
