The first S-25, S-75, Nike-Ajax and Nike-Hercules anti-aircraft missile systems, developed in the USSR and the USA, successfully solved the main task set during their creation - to ensure the defeat of high-speed high-altitude targets inaccessible to the receiver anti-aircraft artillery and difficult to intercept fighter aviation. At the same time, such high efficiency of the new weaponsthat customers had a well-grounded desire to ensure the possibility of its use in the entire range of speeds and altitudes, on which the aircraft of a potential enemy could operate. Meanwhile, the minimum height of the affected areas of the C-25 and C-75 complexes was 1-3 km, which corresponded to the tactical and technical requirements formed in the early fifties. The results of the analysis of the possible course of the upcoming military operations indicated that as the defense was saturated with these anti-aircraft missile systems, attack aircraft could proceed to actions at low altitudes (which later happened).
In our country, the beginning of work on the first low-altitude air defense system should be attributed to the fall of 1955, when, based on the outlined trends in expanding requirements for rocket weapons, the head of the KB-1, A.A. and organized for its decision a laboratory headed by Yu.N. Figurovsky.
The new anti-aircraft missile system was designed to intercept targets flying at speeds up to 1500 km / h at altitudes from 100 to 5000 m, at a distance of up to 12 km, and was designed to ensure the mobility of all its components - anti-aircraft missile and technical divisions attached to them means of radar reconnaissance, control and communications.
All elements of the developed system were designed either on the automobile base, or with the possibility of transporting both trailers using motor vehicles on the roads, as well as by rail, air and sea transport.
In forming the technical appearance of the new system, the experience of developing previously created systems was widely used. To determine the position of the target aircraft and the rocket, a difference method was used with linear scanning of the airspace, similarly implemented in the C-25 and C-75 complexes.
As applied to the detection and tracking of low-altitude targets, a special problem was created by the reflection of the radar signal from local objects. At the same time, in the C-75 complex, the channel of the antenna scanning in the elevation plane was most affected by the noise at the moment when the beam of the probing signal approached the underlying surface.
Therefore, in the low-altitude missile guidance station, an inclined arrangement of antennas was adopted, in which the reflected signal from the underlying surface increased gradually during the scanning process. This made it possible to reduce the illumination of the screens of the target tracking operators by reflections from local objects, and the use of one internal scanner, for which each turn alternately scanned the space of antennas in two planes, allowed the radar to work alone with the transmitting device. Commands on board the rocket were transmitted through a special antenna with a wide radiation pattern using a pulsed coded line. The request for airborne transponders of missiles was carried out through a system similar to that adopted in the C-75 complex.
On the other hand, to realize a narrow radiation pattern of a missile guidance station when scanning space using a mechanical scanner and the permissible dimensions of its antennas, a transition to a higher frequency range with a wavelength of 3 cm was made, which required the use of new electrovacuum instruments.
Due to the short range of the complex and, as a result, the small flight time of the enemy aircraft, an automated missile launch system (APP-125 automated launch device) was originally installed in the SNR-125 missile guidance station, designed to determine the boundaries of the air defense missile system, to solve the launch task and determine the coordinates of the meeting point of the target and the rocket. Upon entering the calculated meeting point in the affected area, APP-125 should have automatically launched a rocket.
To speed up work and reduce their cost, experience in the development of C-75 ground-over missiles was widely used. The B-125 missile, which was originally developed for the Volga M-600 ship-borne air defense system, was played a major role in the completion of the work and the adoption of the C-1 air defense system into service with the country's Air Defense Forces. 125 (now Altair INRI).
The tests of the specially developed C-125 BURS X-NUMX were unsuccessful and it was decided to finalize the B-625 (600K4) missile for ground-based C-90. At its base, a missile defense system was created, which differed from the prototype with a radio control and sighting unit (SD-125) for compatibility with ground-based missile guidance tools.
After successful tests, by Decree No. 735-338, this missile under the symbol B-600P (5B24) was introduced into the C-125 SAM.
The B-600P missile was the first Soviet solid-propellant missile system, made according to the aerodynamic "duck" scheme, which provided it with high maneuverability when flying at low altitudes. To hit the target, the missile is equipped with a high-explosive fragmentation warhead with a radio fuse with a total mass of 60 kg. When it was detonated by a command of a radiofractor or CHP, 3560-3570 fragments were formed with a mass up to 5,5 g, the scattering radius of which reached 12,5 m. In 26 seconds after launch, in the event of a miss, the rocket went up and self-destructed. Control of the rocket in flight and aiming at the target was carried out by radio commands coming from the CHP-125.
In the four compartments of the marching stage, in the order of their placement, starting from the head part, there were located a radio fuse (5Е15 "Strait"), two steering gears, a truncated cone warhead with a safety-actuating mechanism and a compartment with onboard equipment ZRS C-125 intended for combat airplanes, helicopters and cruise missiles (CR) operating at speeds of 410-560 m / s at altitudes of 0,2-10 km and distances of 6-10 km.
Supersonic maneuvering with overloads up to 4 units, targets were hit at altitudes of 5-7 km, subsonic with overloads up to 9 units. - from the heights of 1000 m and more with the maximum course parameters 7 km and 9 km, respectively.
In passive interference, targets were hit at altitudes up to 7 km, and the director of active interference was at altitudes 300-6000 m. The probability of hitting a single missile target was 0,8-0,9 in a simple situation and 0.49-0,88 in passive interference.
The first anti-aircraft missile regiments equipped with C-125 were deployed in 1961.
in the Moscow District Air Defense. At the same time, the C-125 anti-aircraft missile and technical divisions, together with the C-75 and, later, C-200, systems, were introduced into the air defense brigades of mixed composition.
The structure of the air defense missile system includes a missile guidance station (SNR-125), an anti-aircraft guided missile (missile, a launcher launcher carried), a transport-loading vehicle (TZM) and an interface cabin.
The SNR-125 missile guidance station is intended for detecting low-altitude targets at a distance of up to 110 km, identifying their nationality, tracking and subsequent targeting of one or two missiles at them, as well as for monitoring the results of firing. To solve these problems, the SNR is equipped with receiving and transmitting and receiving systems operating in centimeter (cm 3-3,75)
wave range.
In order to reduce reflections from the earth's surface, they are equipped with special configuration antennas, at 45 degrees. deployed in relation to the horizon, providing the formation of radiation patterns in two mutually perpendicular planes for receiving echo signals from the target and signals of the transponders of missiles.
Missile guidance station facilities
Depending on the presence of interference, CHP-125 can use radar or television-optical, with a range of up to 25 km, channels for tracking the targets. In the first case, the target can be accompanied in automatic (AC), semi-automatic (PC-AC) or manual (PC) modes, in the second - by operators in manual mode. During autonomous operation, the search for targets is carried out by a circular (360 degree per 20 s), small sector (5-7 sector sector) or large sector (20 degree) azimuth survey. When changing positions, the antenna post was transported on the attached trailer 2-PN-6М.
The two-beam transported PU 5P71 (CM-78А-1), induced in azimuth and elevation by a tracking electric drive, was designed to accommodate two missiles, their preliminary guidance and an oblique launch into the target. After deployment at the launch site (allowable slope of the site to 2 degrees.) PU required leveling screw jacks.
TZM PR-14А (PR-14АМ, ПР-14Б) was used to transport 5В24 missiles and load launchers with them. This TZM and its subsequent modifications (PR-14АМ, ПР-14Б) were developed in GSKB on the chassis of the ZIL-157 vehicle. The loading time of PU missiles with TZM did not exceed 2 minutes.

The interface and communication cab 5Ф20 (5Ф24, 5X56) ensured the operation of the SNR in target targeting mode from the ACS.
For the early detection of low-flying targets, the division could have been given radars of the P-12 type and the P-15 radars of the decimeter range. To increase the detection range of low-altitude targets, the latter was equipped with an additional antenna-mast device “Unzha”. In addition, further could be shaped apparatus relay communication 5YA61 (5YA62, 5YA6Z) "cycloid", and for the CHP and guidance officers operator training apparatus "Chord" imparted by the S-75 and C-125 rate of one set of four air missile division.

Radar P-12
Radar P-15
All the equipment of the air defense missile system is located in towed car trailers and semi-trailers, which ensured the placement of the division on a relatively level ground with 200x200 m sizes with small closing angles. As a rule, in a prepared position, all SNR-125 facilities were placed in buried reinforced concrete shelters with additional earthen cover, PU - in semi-ring embankments, SAM - in stationary structures for 8-16 missiles in each or at division positions.
The cockpit of the C-125 "Pechora" air defense system
Modifications:
ZRK C-125 "Neva-M" - the first version of the modernization of this system. This decision was made in March 1961, when the C-125 "Neva" was not in service. Works on its improvement should have been carried out by the design bureau of plant No. 304 under the general direction of design bureau XB-1. Adopted by 27.09.1970. The total amount of work involved the creation of a B-601P (5B27) SAM, an expansion and refinement of the SNR-125 equipment applicable to the new rocket, as well as the creation of a new four-beam 5P73 PU to use B-600P and B-XNUMP. TZM (PR-601M, PR-14MA) on the chassis of the car ZIL-14 or the Urals.

The B-601P (5B27) missile was put into service on 1964 in May. The main direction of work during its creation was to develop a new radio fuse and cruise engine on a fundamentally new fuel with high specific impulse and increased density. While maintaining the overall dimensions of the rocket, this led to an increase in the maximum range and height of the lesion of the complex.
From its counterpart ZUR B-600P differed new main engine, fuse,
safety actuator and warhead 72 kg mass, undermining which formed fragments up to 4500 4,72-4,79 g mass. The external difference consisted in two aerodynamic surfaces on the transitional connecting compartment to reduce the range of the starting engine after its separation. To expand the zone of damage, the missile was also aimed at the passive part of the trajectory, and the time of self-destruction was increased to 49 s. Zour could maneuver with overloads up to 6 units and operated at temperatures from -400 to + 500. The new missile defense system ensured the defeat of targets operating at flight speeds up to 560 m / s (up to 2000 km / h) at a distance of up to 17 km in the altitude range 200-14000 m. In passive interference of a given density, the maximum height of the lesion decreased to 8000 m, and the range - up to 13,6 km. Low-altitude (100-200 m) targets and near-sonic airplanes were destroyed at a distance of up to 10 km and 22 km, respectively.
The transportable four-beam PU 5P73 (CM-106) was developed at TsKB-34 (chief designer BS Korobov) with a minimum start angle of the missile defense in 9 degrees. and had a special rubber-metal multisectional circular coating to prevent soil erosion around it during missile launches. The launcher provided for the installation and launch of the B-600 and B-601P missiles, and the loading was carried out successively by two TZMs from the right or left pair of beams.
The main characteristics of C-125M air defense system with 5B27
Year of Adoption 1970
Target hit range, km 2,5-22
Height of target destruction, km 0,02-14
Course parameter, km 12
Maximum target speed, m / s 560
The probability of hitting the aircraft / KR 0,4-0,7 / 0,3
Mass of anti-aircraft / warhead, kg 980 / 72
Reload time, min 1
С-125М1 СРК (С-125М1А) “Neva-М1” was created by further modernization of С-125М СРК, carried out at the beginning of 1970. and adopted with the 5ВХNUMXД missile in May 27. At the same time, a modification of the missile with a special warhead was developed to defeat group targets.
He had increased noise immunity of the missile defense control channels and target sighting, as well as the possibility of tracking and firing in visual visibility conditions at the expense of the Karat-2 (9Sh33А) television-optical sight equipment. This greatly facilitated the combat work on aircraft jammers in terms of their visual visibility. However, TOV was ineffective in adverse weather conditions, when it was directed towards the sun or a pulsed light source, and also did not provide determination of the range to the target, which limited the choice of methods for targeting missiles and reduced the effectiveness of firing at high-speed targets. In the second half of the 1970's. C-125М1 equipment was introduced to ensure firing at the NLC at extremely low altitudes and ground (surface) radio-contrast targets (including missiles with special warheads). The new modification of the 5ВХNUMXД rocket had an increased flight speed and allowed to fire at the targets “in pursuit”. Due to the increase in the length and starting weight up to 27 kg, only three missiles could be placed on any PU 980P5 beams. At the beginning of 73. The CHP-1980 of all modifications to counter anti-radar missiles is equipped with the equipment “Doubler” with 125-1 remote radar simulators, which were installed remote from the station and worked on radiation in the “flicker” mode.
Having proved its reliability and efficiency, the C-125 air defense system is still in service with the armies of many countries of the world. According to estimates of experts and analysts around 530, the C-125 “Neva” air defense missile systems of various modifications under the code name Pechora were supplied to 35 countries and used in a number of armed conflicts and local wars. In the "tropical" version, the complex had a special paintwork to repel termites.
Google Earth satellite image: C-125 air defense system near the city of Lusaka, Zambia
The combat "baptism" of the C-125 ADMS took place in 1970 on the Sinai Peninsula. Each division from the sudden attacks of low-flying aircraft was covered with 3-4 ZSU-23-4 Shilka, a detachment of portable anti-aircraft missile systems Strela-2 and DShK machine guns.

With extensive use of ambush tactics, the first F-4 was shot down on June 30, the second after five days, four Phantoms on July 18 and three more Israeli planes on August 3 on 1970. Three more aircraft of the Israeli Air Force were damaged. According to Israeli data, more 6 aircraft were shot down by Arabic C-125 air defense systems during the October war of the 1973 year.
Satellite image of Google Earth: Air defense missile system С-125 of Egypt, PU of the old two-girder type
C-125 complexes were used by the Iraqi army in the Iran-Iraq war 1980-1988
Years, and in 1991, when repelling air strikes by multinational forces; in Syria, against the Israelis during the Lebanese crisis of 1982; in Libya - for shooting at US planes in the Gulf of Sidra (1986)
Satellite image of Google Earth: S-125 air defense system of Libya, destroyed by air strikes
In Yugoslavia, against NATO aircraft in 1999. According to the Yugoslav military, it was precisely the C-125 27.03.1999 complex that shot down the F-117.
The extreme, recorded case of combat use was noted during the Ethiopian-Eritrean conflict in 1998-2000, when the intruder was shot down by a missile of this complex.
According to many domestic and foreign experts, the Pechora low-altitude air defense system, in terms of its reliability, is one of the best examples of air defense systems. For several decades of its operation to date, a significant part of them have not exhausted their resources and can be in service until the 20-30-s. XXI century. According to the experience of combat use and practical shooting, the Pechora has high operational reliability and maintainability. Using modern technology, it is possible to significantly enhance its combat capabilities at relatively low costs compared to the purchase of new air defense systems with comparable characteristics. Therefore, in view of the great interest on the part of potential customers, in recent years a number of domestic and foreign options for the modernization of the Pechora air defense system have been proposed.
ZRK C-125-2М (К) The Pechora-2М (Pechora-2К) is the first practically implemented domestic mobile (container) upgrade option for this widely known anti-aircraft system. It was developed by the Interstate Financial and Industrial Group (MFPG) Defense Systems (27 enterprises, including Belarusian 3) without attracting budgetary allocations. In the final version, this complex, created on the basis of the newest technologies and modern element base, was presented at the MAKS-2003 International Aviation and Space Salon in the town of Zhukovsky near Moscow in the summer of 2003.
According to the developers, the upgraded Pechora provides combat against all types of aerodynamic means of air attack, especially low-altitude and small-sized targets.
The upgraded rocket increased the range and effectiveness of hitting targets, and replacing the main equipment with digital and solid-state equipment - reliability and service life of the complex. At the same time, the operating costs were reduced and the composition of the crew of the complex was reduced. The installation of the main elements of the air defense system on the car chassis, the use of software-controlled hydraulic antenna, modern communications equipment and satellite navigation equipment ensured the mobility of the air defense system and significantly reduced the time it was deployed to the combat position. The complex was able to interface with remote radars and higher-level gearboxes via telecode channels.
The mobile Pechora-2M with 5B27E missiles has an increased range (from 24 to 32 km) and speed (from 700 to 1000 m / s) of targeted targets, an increased number of launchers (from 4 to 8) and target channels (to 2 with use of the second antenna post), as well as reduced (from 90 to 20-30 minutes) total time of deployment of the complex to the position.
In addition, due to a significant increase in the distance between the control cabin, antenna post and launchers, the use of radio protection complex and a new optical-electronic system, the survivability of the main combat elements of the complex under conditions of its electronic and fire suppression from the enemy was sharply increased. He became mobile with a simultaneous increase in its operational reliability. The new element base used for the modernization of the SNR, provided the detection of air targets with EPR 2 square. m flying at an altitude of 7 km and 350 m, at a distance of 80 km and 40 km, respectively. Equipping the station with a new optoelectronic system (ECO) ensured reliable detection of targets in day and night conditions. ECO (optical-electronic module at the antenna post and information processing unit in the control cabin) is used to detect and measure the angular coordinates of air targets during the day and night. Television and thermal channels allow air targets to be detected at distances up to 60 km (by day) and up to 30 km (by day and night), respectively.
Mobile PU 5P73-2 ZRK C-125 "Pechora-2M" defense of Venezuela
The two-girder PU 5P73-2 is located on the modified MZKT-6525 chassis (8021) with a new, specially designed and placed in front of the engine cabin. With a mass in 31,5 t, it can move with a maximum speed of up to 80 km / h. The calculation from 3 man ensures the transfer of PU from the traveling position to the combat position in no more than 30 minutes.
In addition, the modernized Pechora differs from the prototype by a high degree of automation of combat work and technical condition monitoring, ease of information exchange with external sources of radar information, between SNR and launchers, a reduced amount of maintenance work, in 8-10, with a reduced range of spare parts . At the request of the customer on the SNR can be installed equipment of the national system for determining the nationality of the target.
To protect the Pechora-2М / К air defense system against attacks of the Harm-type anti-radar missiles (AGM-88 HARM), induced by the radiation of the antenna post, a special CRTZ-125-2М radio protection system was specially developed.
It consists of 4-6 transmitters OI-125, control unit and communication OI-125BS, spare parts, stand-alone power supply (220В / 50Hz) and a vehicle type "Ural-4320". The work of КРТЗ-125-2М is based on the principle of masking antenna post signals with signals from a group of transmitters, provided that the power of each of them is greater than or equal to the power of the background radiation of the antenna post in a given sector of responsibility.
Burst pulses emitted by the OI-125 group constantly change their parameters according to
a given program, putting a GOS PI, leading spatial interference in angular coordinates. With a uniform placement of the OI-125 around the antenna post (along a circle with a diameter of 300 m), the missiles are moved away from it to a safe distance for it. It is important that КРТЗ-125-2М can be successfully used in conjunction with any Russian-made air defense missile systems and air defense missile systems.
Based on:
http://sfw.so/1148881407-zrk-pesora-ne-redaktirovat.html
http://rbase.new-factoria.ru/missile/wobb/c125/c125.shtml
http://www.soldiering.ru/army/airdefence/russia/c-125.php