India's Air Defense System: Service, Combat Use, and Modernization of First-Generation SAM Systems
In 1962, India suffered a defeat in a border conflict with China, after which the Indian leadership began a process of modernizing its armed forces. One of the key priorities was ensuring the integrity of the country's airspace and protecting strategically important military and civilian facilities from air attack.
Simultaneously with the acquisition of MiG-21 fighters from the USSR, the Indian military received new radars, communications, and combat control systems. This was fundamentally new for India. weapons became Soviet anti-aircraft missile SA-75MK Dvina air defense systems, which were used for over a quarter of a century for the capital's air defense and deployed in areas bordering Pakistan. In the 1960s and 1970s, SA-75MK air defense systems were repeatedly used against Pakistani high-altitude reconnaissance aircraft, bombers, and balloons, and the presence of these systems became a significant deterrent during the Indo-Pakistani conflict.
In the mid-1980s, India received a significant number of S-125M Pechora-M air defense systems, which were primarily used to cover airbases, large garrisons, ports, transport hubs, and administrative and industrial centers in areas bordering Pakistan and China, as well as in the central part of the country. The S-125M air defense systems performed remarkably well in challenging, hot and humid climates. These systems required fewer materials and labor resources to maintain than the S-75MK with liquid-propellant missiles. Relatively recently, India initiated a modernization program for its existing S-125M air defense systems, aiming to improve their combat performance and extend their service life.
Operation and combat use of the SA-75MK Dvina air defense missile system in India
After India's independence, its armed forces were equipped with Western-made weapons, primarily British, French, and American. In 1962, India suffered a defeat in a border conflict with China, and the Air Force command declared the need to protect strategically important installations with anti-aircraft systems capable of countering bombers and reconnaissance aircraft operating at medium and high altitudes. Initially, the Indian military considered acquiring American and British point-based air defense missile systems.
In 1958, the US Army adopted the MIM-14 Nike-Hercules long-range air defense system with a solid-fuel missile and a radio-command guidance system.
Starting position of the MIM-14 Nike-Hercules
In the early 1960s, the American Nike-Hercules could engage large, high-altitude, subsonic targets at ranges of up to 130 km. Its altitude reach was 30 km. But the price for such impressive performance by the standards of the time was the very high cost, complexity, and bulkiness of the system, which, in its early versions, was essentially stationary.
The US also had a very successful MIM-23 HAWK air defense system with semi-active radar guidance, which entered service in 1960.
Towed launcher for the MIM-23 HAWK air defense missile system
The first modification of the MIM-23A solid-fuel anti-aircraft missile could engage targets at ranges of up to 25 km. Its ceiling was 11,000 m.
From the 1960s to the 1980s, Nike-Hercules and Hawk air defense systems were actively exported to US allies. However, due to political tensions stemming from the Indian leadership's desire to manage international relations independently and prevent foreign interference in its domestic affairs, Washington refused to supply New Delhi with the most advanced weaponry available at the time.
The United Kingdom offered the Thunderbird Mk. I and Bloodhound Mk. I air defense missile systems for export. The Thunderbird used solid-fueled missiles, while the Bloodhound used liquid-fueled ramjet engines. Both missiles were equipped with semi-active radar homing heads. Target illumination was provided by dedicated radars.
Thunderbird anti-aircraft missile
The solid-fuel Thunderbird Mk. I SAM had a firing range of 40 km and an altitude reach of 20 km. The first variant of the Bloodhound Mk. I could engage targets at a distance of just over 35 km, which was comparable in kill zone to the Soviet SA-75MK Dvina system, which used missiles powered by liquid fuel and oxidizer.
The launch site of the Bloodhound air defense missile system
Although the British missiles were easier to operate, as they didn't require regular refuelling and draining of toxic fuel and a corrosive, flammable oxidizer after a period of combat duty, they were significantly heavier than the Soviet V-750V SAMs. Furthermore, the British missiles themselves, like the systems as a whole, were significantly more expensive and much more complex than the target system. Defense, proposed by the Soviet Union. However, the determining factor in this matter was most likely New Delhi's desire to pursue an independent foreign policy and diversify its arms imports. Consequently, active military-technical cooperation with the USSR began in the early 1960s.
After the Indian leadership signed the relevant contracts, the Soviet Union began supplying large quantities of various weapons. Particularly valuable for enhancing the combat potential of the country's air defenses were the P-12, P-30, and P-35 radars, MiG-21 fighters, and SA-75MK Dvina anti-aircraft missile systems.
Between 1964 and 1972, the Indian Air Defense Forces received 25 divisional SA-75MK systems, as well as 639 combat and 10 training V-750V anti-aircraft missiles. The SA-75MK system (a modification for non-socialist countries) differed from the SA-75M SAM system adopted by the USSR and supplied to Warsaw Pact countries in its identification system and combat control equipment. It is worth noting that the SA-75M system was adopted in the Soviet Union in 1959, and at the time, it was the most advanced air defense system, demonstrating the importance the Soviet government placed on improving relations with India.
The V-750V radio-guided surface-to-air missile, used in the SA-75MK air defense missile system, had a conventional aerodynamic configuration and two stages: a sustainer stage powered by a liquid-propellant rocket engine and a booster stage powered by a solid-fuel booster motor. The booster stage, which lasted 4,5 seconds, provided the missile's acceleration and a reliable launch from an inclined launch pad. The sustainer motor's operating time was determined by the capacity of the fuel and oxidizer tanks and was approximately 25 seconds. The choice of a liquid-propellant sustainer motor, powered by TG-02 fuel (a mixture of xylidine and triethylamine) and AK-20 oxidizer (nitric acid saturated with nitrogen oxides), was dictated by the lack of solid propellant formulations capable of providing the required firing range in the USSR in the late 1950s, when the SA-75 air defense missile system was being developed. The use of a liquid-propellant rocket engine allowed for a high average trajectory velocity with a limited launch mass and ensured an inclined launch, corresponding to the fastest possible approach to the target. In addition to fuel and oxidizer, the rocket carried a tank for the OT-155 initiating fluid (isopropyl nitrate), which, when decomposed, spun the turbopump unit that delivered the propellant components.
The B-750V anti-aircraft missile on its launcher.
In addition to the early modification of the V-750V SAM, India also received upgraded missiles with an increased kill zone from 29 to 34 km and an altitude reach of 22 km. Later-production missiles also utilized passive guidance to increase their firing range after the propellant had been exhausted. The warhead is detonated by a signal from a radio fuse or by a command from the SNR-75MA station upon approach to the target. The missile self-destructs after its flight.
SNR-75 anti-aircraft missile guidance station
The main equipment was housed in three cockpits. The SA-75MK anti-aircraft missile battalion was equipped with a P-12MN reconnaissance and target acquisition radar with a moving target selection system, remote control, and a remote 360-degree view display. Six launchers were deployed at the firing position. PR-11AM transporter-loader vehicles with ZIL-157KV tractors were used to deliver missiles to the launchers. The transporter-loader vehicle could store an additional 18 missiles in a state of intermediate readiness.
A PR-11AM transport and loading vehicle with a V-750V missile, displayed at the Republic Day parade in New Delhi in 1968.
Unlike the USSR, where the S-75 family of systems primarily served with the country's Air Defense Forces, in India the SA-75MK SAMs were transferred to the Air Force, and Indian anti-aircraft missile battalions were referred to as squadrons. Missile squadrons were numbered the same as airborne units. By 1972, when the structure of the Anti-Aircraft Missile Forces was finally established, there were six wings (regiments) with four missile squadrons each. Another squadron was a training squadron. In the first stage, the air defense squadrons were deployed in the Chandigarh-Ambala region, in the vicinity of Kolkata, New Delhi, and Vadodara. During the initial stage, Indian missile squadrons were primarily stationed, which was due to the protection of specific facilities and the inability of the Pakistani combat aviation actively counter them. It is known that only one SA-75MK system, considered a mobile reserve, was regularly deployed from place to place.
When deployed at fixed positions, the launchers were initially protected by embankments and sandbags, and then some of the systems were placed on permanent concrete platforms equipped with strong shelters for equipment and personnel.
Following the Indo-Pakistani War of 1965, the systems and missiles in service at the time were upgraded, which allowed for a lower altitude limit, improved jamming immunity, and an increased probability of hitting an air target.
During the 1965 Indo-Pakistani War, Dvina systems engaged unidentified targets several times. However, no confirmed successes were achieved, and claims of shooting down a Pakistani C-130 aircraft west of Delhi are untrue. The next time the SA-75MK SAM system engaged in combat was two weeks after the ceasefire. The target was a Pakistani RB-57F sent to photograph Indian airbases and railway junctions. This American-made aircraft, capable of flying at altitudes exceeding 20 kilometers, was considered invulnerable to the MiG-21 and Mosquito fighters of the Indian Air Force.
RB-57F high-altitude reconnaissance aircraft
The RB-57F high-altitude reconnaissance aircraft was promptly detected by radar, and after entering the kill zone of a missile squadron based near Amritsar, three missiles were fired at it. The warheads of two B-750V SAMs detonated near the intruder, seriously damaging it. However, the Pakistani pilot remained in control and made an emergency landing in Peshawar. The damaged reconnaissance aircraft was subsequently sent to the United States for repairs, but it proved beyond repair and was written off. It's worth noting that the Pakistani RB-57F pilot was extremely lucky – in similar situations, B-750V anti-aircraft missiles shot down several American-made RB-57 and U-2 high-altitude reconnaissance aircraft over China, the USSR, and Cuba.
By the start of the 1971 war, all Indian SNR-75MA guidance systems and B-750V anti-aircraft missiles had been upgraded, allowing them to lower their altitudes to 300 meters. This upgrade proved timely, as Pakistani B-57B bomber pilots, aware of their SAM systems, effective at medium and high altitudes, switched to low-altitude flights.
The Pakistan Air Force command made several attempts to bomb Indian airfields using B-57B bombers. However, they were met with anti-aircraft missile launches. Ultimately, the Pakistanis failed to successfully bomb them, but the Indian SA-75MK crews also achieved no confirmed success. Faced with a screen of Dvina missiles, the Pakistan Air Force command, unwilling to risk the B-57B bombers, no longer sent them to strike deep into Indian territory. Instead, to wear down Indian air defenses, they launched a mass of high-altitude balloons with metalized skins, neutralizing them with approximately fifteen expensive B-750V SAMs. According to unconfirmed reports, in 1971, an Indian An-12, mistaken for a Pakistani C-130, fell victim to an SA-75MK air defense system.
In fairness, it should be noted that the results of the firings against Pakistani bombers could have been better. However, this was not the case due to the poor training of Indian crews and the insufficient tactical literacy of the control officers. Furthermore, during actual launches of the B-750V SAMs, it became clear that the operating modes of the guidance equipment were far from optimal due to a formal approach to technical regulations, which negatively impacted jamming immunity and accuracy. In some battalions, the missile launchers did not have combat-ready, properly fueled, and armed missiles, and they were unable to fire in a timely manner. After the Pakistani air attacks began, the Indian Air Force command took emergency disciplinary and organizational measures aimed at improving the combat readiness of the missile squadrons.
Although the SA-75MK SAM system was becoming obsolete by the mid-1970s, it continued to be a significant deterrent, guaranteeing the integrity of Indian airspace. To extend its service life, Soviet-supported maintenance and repair of hardware, launchers, transporter-loader vehicles, and anti-aircraft missiles was organized at a repair facility in Baddi, Himachal Pradesh, in 1980-1981. The last combat deployment of the Dvina system, with its redeployment to new positions, occurred in 1987, during yet another flare-up in tensions with Pakistan.
As the SA-75MK air defense missile systems wore out and became obsolete, it became increasingly difficult for crews to maintain them in working order. In the second half of the 1980s, it became clear that the life cycle of these systems was ending and they were due for decommissioning. To replace the SA-75MK in air defense of air bases and to provide air defense for other important facilities, India acquired the low-altitude S-125M Pechora-M air defense missile system.
The decommissioning of the SA-75MK air defense missile system began in 1987 after 27 years of service. Indian sources claim that all Dvina air defense missile systems were removed from combat duty in 1992. By that time, fifteen anti-aircraft missile squadrons were deployed.
The location of SA-75MK air defense missile systems in India as of 1991.
Currently, the Indian Dvina air defense missile systems have become part of stories, and they can only be seen in a museum exhibit.
However, the main components of the systems were not immediately disposed of and remained in reserve for over a decade. According to Indian sources, the launchers, missile guidance systems, and transporter-loader vehicles were stored at the Juttarlai airbase in Rajasthan province until 2003.
Google Earth satellite image of a former SA-75MK air defense missile system on the southern outskirts of New Delhi. The image was taken in June 2024.
English-language sources have claimed that for some time after the B-750V liquid-propellant SAMs were deactivated, operational SNR-75MA missiles remained at positions near the Indo-Pakistan border. The guidance stations, now deactivated, periodically activated, thus deterring Pakistani Air Force aircraft, which triggered warning systems warning them of being targeted by anti-aircraft missile systems.
Google Earth satellite image: a former SA-75MK air defense missile system position near Chandigarh, 250 km north of New Delhi.
Several permanent firing positions are still maintained in good condition and are still used to house modern mobile air defense systems and radar stations.
Operation and modernization of Indian S-125M Pechora-M air defense systems
As is well known, the S-75 family of SAMs are the most widely deployed Soviet point-based air defense systems. They were successfully used not only against high-altitude reconnaissance aircraft and long-range bombers, but also against tactical and carrier-based combat aircraft. At the same time, all S-75 variants suffered from inherent weaknesses such as relatively low mobility, low firepower, and the need to fuel the missiles with toxic, corrosive, and flammable liquid fuel and oxidizer components. As early as the second half of the 1950s, it became clear that combating low-altitude targets required a relatively simple and inexpensive point-based system with solid-fuel SAMs. This system, by reducing the size of the missiles, could increase their number on the launchers, thereby increasing the ready-to-use ammunition load.
The development of the S-125 transportable single-channel anti-aircraft missile system for combating low-altitude targets was mandated by Council of Ministers Resolution No. 366-255 of March 19, 1956. The S-125 air defense system, armed with the V-600P missile, entered service on June 21, 1961. The development of the new system utilized a well-established radio command guidance system.
Thanks to its well-thought-out technical solutions, a successful combination of cost and effectiveness, good combat and operational characteristics, and high modernization potential, the S-125 became the best Soviet first-generation air defense system, which participated in many conflicts and is still in use in a number of countries.
Almost immediately after the first version of the "125" was accepted into service, work began on developing an improved modification. In 1964, serial production of the V-601P SAM began, intended for the S-125M SAM system. However, this missile could also be used with the S-14. The main differences from the previous V-600P model lay in the cruise engine, which ran on a more energy-intensive fuel with a high specific impulse and increased density. While maintaining the overall dimensions of the missile, this made it possible to increase the maximum firing range and engagement altitude. The V-601P SAM could engage targets with a flight speed of up to 560 m/s, at a range of up to 17 km, and at altitudes of 200-000 m. In passive jamming of a given density, the maximum engagement altitude was reduced to 8000 m, and the range to 13,6 km. Low-altitude targets (100-200 m) could be successfully engaged at ranges of up to 10 km. Subsonic aircraft operating at medium altitudes could be engaged at ranges of up to 22 km.
The missiles were launched from a new 5P73 (SM-106) transportable four-boom launcher. A battalion typically had three launchers, and the number of ready-to-use SAMs reached 12. Loading was accomplished sequentially by two PR-14M TZMs mounted on a ZiL-131 truck chassis.
The upgraded SNR-125M guidance station featured enhanced jamming immunity for the SAM control and target acquisition channels. It enabled engagement of air targets at extremely low altitudes, as well as ground (surface) targets with radio-contrast properties.
Antenna post SNR-125M
All SAM system equipment was housed in towed trailers and semi-trailers, allowing for autonomous deployment of the battalion on a 200x200m platform. At the fixed position, the equipment cabins and diesel generators were housed in reinforced concrete bunkers, the launchers were housed in semi-circular earthen embankments, and the SAMs were housed in fixed structures with 8-16 missiles each, or at battalion positions.
An unprecedented number of S-125M Pechora-M air defense systems were delivered to India; by the end of the 1980s, the country had a total of 60 S-125 anti-aircraft systems and more than 1500 missiles for them.
To ensure timely detection of aerial targets, the S-125M battalion was typically equipped with P-18 two-axis meter-range and P-15 decimeter-range radars, or an ST-68U (19Zh6) three-axis radar. When deployed in the field, R-140M shortwave radios and radio relay equipment ensured uninterrupted communication with higher command posts.
The bulk of India's S-125M air defense systems were deployed at airbases in the northwestern states along the border with Pakistan. In most cases, the launchers were empty, apparently to protect them from the scorching sun. The transporter-loader vehicles carrying the missiles were housed in climate-controlled concrete hangars. The TZVs were expected to move to the launchers and quickly load the missiles if the situation worsened.
Ten years ago, approximately two and a half dozen S-125M air defense systems were on combat duty, and approximately fifteen more systems were in storage.
The deployment of the S-125M air defense missile system in India as of 2015.
In the 1980s, India began work on its own Akash air defense system, intended to replace the Soviet S-125M and Kvadrat air defense systems. However, work dragged on, and although the Akash air defense system has already been adopted, it has not completely supplanted the Soviet military-industrial complex, and more than ten Indian S-125M systems remain in service.
In 2016, the Indian government announced a $272 million tender for the modernization of 16 S-125M air defense missile systems. According to the technical specifications, the Soviet-made systems were to be refurbished, fully digitalized, and integrated with the air defense region control system, with a 15-year service life extension. The SNR-125M guidance system was to be modernized and brought into compliance with modern requirements. There is no reliable information regarding the modernization of the V-601P anti-aircraft missiles, but it is reasonable to assume that they at least underwent refurbishment, including replacement of old components and solid propellant.
As part of the tender, proposals were sent to both public and private Indian defense companies: Tata Power, Larsen and Toubro, Reliance Defense, Offset India Solutions and Bharat Electronics Limited.
Practical work to restore the S-125M began in 2020. The systems removed from their firing positions were replaced with domestically produced Akash air defense systems, which was intended to preserve the air defense of the facilities protected from air strikes.
For example, we can see this picture at the Ambala airbase (Haryana state):
Google Earth satellite image of the S-125M air defense missile system at Ambala Air Base. The image was taken in March 2022.
Google Earth satellite image of the Akash air defense system at Ambala Air Base. The image was taken in November 2023.
Until April 2022, an S-125M air defense system was deployed at a position near the runway. It was later removed and sent for modernization, combined with repairs, and was temporarily replaced by an Indian-made Akash air defense system.
Google Earth satellite image of an S-125M air defense system deployed at Ambala Air Base after modernization. The image was taken in April 2025.
An image dated April 2024 shows the S-125M air defense system, which has been modernized and remains in this position to this day. The most recent publicly available satellite image of the Ambala airbase and its surrounding area was taken on April 8, 2025.
Thus, it can be concluded that the Soviet-made S-125M air defense systems will continue to serve in the Indian Air Force's anti-aircraft missile units after modernization. Experts believe their service life could continue until 2035.
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