Noon, XXI century. But some continue to stubbornly deny the role of modern technology. Especially if the conversation concerns foreign models of military equipment. Especially if they are stealth. Then - uhh, the discussion will be hot.
However, getting burned about this topic is no longer as dangerous as it used to be. At present, the Russian Armed Forces are adopting a whole generation of modern technology, in which the very technology of "stealth" is present.
This material presents an analysis of the article "On Invincible Stealth", not so long ago published on the pages of a popular Internet resource. In my opinion, that article is rife with various inaccuracies and in general has the wrong message aimed at underestimating the role of stealth technology in modern combat.
Stealth is not invisible to radars, stealth is only "low" visibility
The Russian word “invisible” was coined by the Russian-language media. Abroad, “Stealth” remained “stealth” (which means “secretly, secretly”).
It is not clear why the author put the word “small” in quotation marks. The effect of reducing the visibility exists and has been proven in practice. How small it is, we can judge by the facts below.
Stealth is perfectly visible in the optical range, near infrared, far infrared
For 50 years, radar has been the main and main means of detecting air targets. Low attenuation of electromagnetic waves in the atmosphere makes it possible to obtain long detection ranges in all weather conditions.
The author is deliberately disingenuous, switching the reader's attention to the optical and infrared ranges, although one can just as well declare the visibility of "stealth" in the ultraviolet.
Take your eyes off your monitor for a second and look from the back of the room at the window. There is a fly on the window. A barely visible dot on the glass. This is how an enemy fighter pilot sees from a distance of five kilometers. In general, in the age of radar and supersonic speeds at long (and even medium) distances, it is useless to rely on the visible range.
Optics helped only once. The most intelligible of all versions of the destruction of the F-117 over Belgrade is the use of an optical guidance channel: the anti-aircraft gunners accidentally saw an insolent stealth flying below the clouds, and managed to launch a rocket. This is indicated both by the characteristics of the S-125 air defense missile system itself (the Karat-2 TV sight) and the testimony of the participants in the incident themselves - the battery commander Zoltan Dani and the pilot of the downed Nighthawk Dale Zelko (was shot down when he broke through the lower edge of the clouds). Luck never happened again. Although, according to NATO, the clumsy stealth of the first generation made over 700 sorties over Yugoslavia.
Pilots of modern "Su" are assisted by an optical location station (OLS), but this technique is still focused on close air combat. At the same time, technologies also do not stand still: there are proven ways to reduce the IR signature of an aircraft (mixing exhaust gases with cold air). Note the flat nozzles of the F-22 engines. Or the aft part of the F-117 and B-2 stealth bombers: it is designed in such a way as to exclude the possibility of "peeking" into the engine nozzles from the lower hemisphere. However, this is not the point.
At medium and long distances, radar remains the main and only means of detection.
That is why stealths have such chopped shapes and many parallel edges and edges
Fair observation. The parallelism of edges and edges is the basis of modern stealth technology. As well as:
- the requirement for an internal suspension of weapons;
- masking of engine compressor blades (curved air intake ducts, radar blockers);
- exclusion of protruding parts on the surface of the fuselage and wing (antennas, sensors, air pressure probe);
- installation of an uninterrupted canopy of the cockpit;
- improving the quality of assembly, using large-sized panels of complex shape and reducing the gaps between the joints of the sheathing panels;
- "sawtooth" shapes of the edges of the holes;
- as well as auxiliary measures in the form of ferromagnetic paints and radio-absorbing coatings.
… To be detected by some hypothetical radar not at a distance of 400 km, but only at 40 km, the plane must scatter the reflected signal 10,000 times less
The RCS of conventional fighters is estimated at about 10 square meters. According to our experts, the EPR of the F-22 should be at the level of 0.3 sq. m, that is, only 300 times less, and not 10,000.
Let's help the respected author a little in arithmetic. Dividing 10 by 0.3 will give ≈30.
The target detection range of the radar depends on the generator power, antenna directivity, antenna area, receiver sensitivity and RCS of the target.
Further, using the basic equation of radar, it is easy to establish that a 30-fold decrease in RCS will give approximately 2, 3 times less detection range of "stealth" in comparison with a conventional fighter.
And this already threatens to disaster.
Aerial patrols using only the radars of the fighters themselves, irradiating a given area from many angles, greatly increases the risk of detection
That is why no one does this in combat conditions.
Detection of air targets is entrusted to an early warning aircraft (AWACS), while the radars of the fighters themselves are switched on only at the moment of an attack.
To detect stealth, AWACS will be forced to approach the enemy. This contradicts the very concept of AWACS, which must control the airspace from a distance of hundreds of kilometers, outside the zone of operation of enemy aircraft.
F-22 in stealth mode for the sake of reduced visibility should itself become practically blind and deaf. The mode of complete radio silence, the radar is turned off and hidden, even the radio signal cannot be simply received, because for this you need to expose at least some antennas, which will immediately begin to scatter the signal. The only option is some kind of one-way satellite communication channel, when the receiving devices look up into space
Everything is just like that. Fighters try not to turn on their radars, detection and target designation comes from AWACS via satellite.
On the shock F-117, the radar was absent as such. In flight over enemy territory, the pilot of the Nighthawk even turned off the radio altimeter. Only passive means of collecting information (radio interception, thermal imagers, GPS data).
As they say, well, well. What will happen to the EPR of the F-22 with lateral or even multi-angle illumination, what does it have in general with EPR in projections other than the frontal one, is a great US state secret
The best kept secret is the one who does not know it, but in the case of the "Raptor" everything is written on its fuselage. Without even going into the calculations, the RCS of the F-22 and PAK FA should be ten times lower than that of the 4th generation fighters (details in the paragraph on the parallelism of edges and edges). In any of the selected projections.
Moreover, keeping in mind its lower visibility, a stealth fighter is much more likely to take an advantageous position for an attack than a conventional fighter. It won't be easy to flank the stealth.
For example, N035 "Irbis", Su-35S radar. Target with EPR 0.01 sq.m. it detects at a distance of 90 km
The source of this data is the verified resource "Wikipedia", and a further link to the site of the Research Institute of Applied Problems named after V. V. Tikhomirova confirms everything except the data on the target with an RCS of 0.01 sq. m.
Since the game went wrong, what prevents us from bringing data from another trusted source?
Detection of air targets depending on their RCS and distance (in nautical miles). The AN / APG-77 station (Raptor fighter radar) demonstrates the best performance among the presented radars. But even she, in the opinion of the Yankees themselves, can distinguish a target with an EPR of 0.01 sq. m at a distance of no more than 50 km. And the target with EPR 0.3 sq. M. - no more than 100 km
Finally, one must understand that a fighter's radar is not an “all-seeing eye” due to the limited size of the antenna, whose aperture (diameter) does not exceed one meter. What can this "baby" see when even the huge antennas of the S-400 air defense missile system can distinguish a "fighter" -type target at a distance of no more than 400 km?
Maybe he will see something. But advertising brochures will never say in which sector the maximum detection range of the Irbis is provided (according to one version - in the viewing area of 17.3 ° x17.3 °, ie 300 sq. Degrees). And what is the time for the accumulation of data, during which the on-board radar processor will be able to determine the location of the target in the selected area of the sky with a 90% probability. But this is what ultimately determines the capabilities of radars in real conditions.
Ground-based radars are not strictly limited either by size, or by the number of antennas, or by power, or, as a consequence, by the centimeter wavelength range. For VHF waves, both stealth and non-stealth are the same
Another appeal to the ranges of the electromagnetic spectrum with the expectation of gullible inhabitants. The joke is that absolutely all radars that are part of anti-aircraft missile systems (S-300/400, Aegis, Patriot) operate in the range of centimeter and decimeter waves.
VHF radars have long been removed from service, even in third world countries. The dislike of the military for such radars is understandable: such a radar is not able to form a narrowly directed "beam" and, as a result, has a low resolution. The second incurable disease of meter radar is the huge size of the antenna.
The exception only confirms the general rule: the Russian army has adopted the 55Zh6M "Sky" interspecific radar complex, which includes a module with a meter-range radar (RLM-M). Alas, this complex is not intended for use as part of anti-aircraft missile systems and serves only to control air traffic.
It is worth noting that at least two radars are used as part of the air defense system. Depending on the level of those. development and the selected control / guidance method requires an observation station (sometimes multifunctional, capable of programming the autopilots of launched missiles) and a fire control radar, "highlighting" the target. In an extreme case, the “fire and forget” scheme is used, when the missile defense system is equipped with an active radar seeker, which independently “illuminates” its target.
Of course, there can be no talk of any meter range radars.
The nose cone of the F-22 in hidden mode should not be radio-transparent, so as not to violate the geometry of the reflective surfaces of the aircraft. But if you want to at least passively peep the surrounding air with the radar, you will have to make the fairing radio transparent, otherwise the radar, if it can emit a signal through it, will definitely not be able to receive anything back … Trouble …
Trouble: the respected author has not heard of frequency-selective surfaces.
The only long-range missile in the F-22's armament is the AIM-120C. Its range is 50-70 km (already a dangerous distance even in stealth mode), in new modifications they claim about 100 km
AIM-120 AMRAAM medium / long-range guided missile
Modification “C-7” has a max. with a launch range of 120 km (adopted for service 11 years ago). The newer modification “D” has a launch range of 180 km.
You can, of course, rest your horn and say that the engineers at Raytheon know nothing about rockets. But these are the numbers that all sources broadcast. The data on 50-70 km given by the author refers to the early modifications of AMRAAM, originally from the 80s.
It flies to the target "from memory", using the inertial guidance system. If you do not carry out radio correction, then the aircraft fired by such a rocket, at the time of detection of radar irradiation (which means that someone pointed and, possibly, shot), it is enough to sharply change the direction of flight, so that the rocket "from memory" flew completely to the wrong place, where after 40 -60 seconds (flight time of AIM-120 from maximum range) will be its target
A two-way communication channel, like any other modern long-range air-to-air missile system, the fighter's radar continuously calculates the target position and transmits corrections to the missile launched. The attacking fighter has nothing to fear at this moment - the enemy does not have time to track the operation of the radar and take retaliatory measures. The attack began, the flight time of the missiles was 40-60 seconds.
After that, the fighter's radar can be turned off again. Operators from AWACS flying behind will tell the pilot about the results of the battle.
Its homing head captures the target only at a distance of 15-20 km
Or maybe it doesn't. There are reasonable doubts about the effectiveness of the ARGSN modern missiles against stealth aircraft. A miniature radar in the nose of the rocket can hardly distinguish even ordinary fighters (EPR 3 … 10 meters) at a distance of a couple of tens of kilometers. You can imagine how difficult it will be for a rocket to find a Raptor or a PAK FA!
Combined guidance (ARGSN + IR seeker), attempts to reduce the likelihood of a miss and bring the missile as close as possible to the target - within hundreds of meters, from where its seeker will be guaranteed to detect the target … Fighting "stealth" will require changing the usual approaches in the field of creating missile weapons … The headache is enough for everyone.
Low visibility matters only as one of the factors when other characteristics of the aircraft are not sacrificed to it
Its unusual appearance from dozens of polygons, the "lame dwarf" F-117 was indebted to the technologies of the 70s. The computational power of ancient computers was clearly not enough for calculating the EPR of complex surfaces of double curvature.
At present, the issue with computer technology for calculating EPR and 3D printers that make it possible to manufacture large-sized panels of complex shapes can be considered closed. The flight characteristics of the fifth generation fighters are no different from their predecessors, and in some ways even superior. The requirement of parallelism of the edges is not always effective from the point of view of aerodynamics, however, the engineers managed to compensate for this circumstance due to the greater thrust-to-weight ratio of the Raptors and PAK FA. A certain role was played by the placement of weapons in the internal bomb compartments, which also "refined" the appearance of the machines, reduced frontal resistance and reduced the moment of inertia of fighters.
This is indirectly confirmed by the fact that only Americans are running around with "stealth", while the rest of the world moved to practical work in this area only when it became possible to develop stealth aircraft without sacrificing other characteristics
Quite a strange statement.
The Yankees were pioneers in this area: the first flight of "Have Blue" (the predecessor of the F-117) took place almost 40 years ago, in 1977. To date, the fourth stealth aircraft is being serially built overseas (not counting experimental models and UAVs).
Since 2010, Russia has officially joined the stealth aircraft developers club, demonstrating the flight of its fifth generation fighter. In fact, the development of the domestic PAK FA has been going on for 15 years, since the early 2000s.
China breathes in the back of our heads with its crafts J-20 and J-31.
The effect of reducing the visibility exists and is aimed at increasing the survival factor of the vehicle in modern combat. They are working on a partial reduction in visibility even where it was not originally planned to create unobtrusive equipment (Su-35S, F / A-18E / F, modernized Silent Eagle).
At the heart of the stealth technology there are no secrets and materials with unusual properties. “Stealth” is sound logic, multiplied by competent calculation and supported by the power of modern technologies. Ultimately, the result of reduced visibility is based on the shape of the aircraft and the quality of its skin. In this regard, modern techniques of the "Stealth" technology cannot cause deterioration in the flight characteristics of aircraft.
The high cost of fifth-generation stealth fighters, like the B-2 stealth bomber, is not so much due to the stealth technology as the cost of developing high-tech "stuffing" for these aircraft (radars, electronics, engines).
Domestic and foreign samples of stealth technology:
Corvette pr. 20380 ("Guarding")
Lafayette-class stealth frigate, France, 1990
Stealth destroyer "Zamvolt"
Chengdu J-20, China
