Air Defence: De-Mystifying Facts from Euphoria
Lt Gen (Dr) V K Saxena (Retd), PVSM, AVSM, VSM


If there was one news that dominated the media space like no other in the recently concluded BRICS Summit on 15-16 Oct, it was the one on the signing of the contract between India and Russia for the purchase of five Regiments of S 400 Triumph Air Defence System at the cost of some 39000 Cr. Many a catchy phrases were thrown up - 'Game Changer' , 'Best System', and 'One Remedy for All needs', to quote a few. As the heading says, this piece tries to demystify the euphoria by bringing the facts on the table and attempts to answer the question - "What will be the impact of the induction of S 400 system in our country".

A word About the System and its Evolution

S 400 is a long range air defence and anti-Missile system. It provides a counter to the air threat from our potential adversaries likely to be prosecuted by multiple air threat vehicles, like multi-role modern aircrafts, attack helicopters, unmanned aerial vehicles (UAVs) and their combatized version (UCAVs), cruise missiles, anti-radiation missiles, and more. Today, most of the modern air threat vehicles as mentioned above, strike in all-weather conditions and possess the ability of deep strike with precision and stand-off capability when attacks are delivered from long ranges without the need to close in with the deployed weapons. S 400 being an anti-missile system, can provide a full air defence shield against the adversary's Surface-to-Surface Missiles (SSMs) including the nuclear capable missiles.

Evolution of the system takes us back to 1978-79 when the then Soviet Union started to develop long range Surface to Air Missiles (SAM) to provide area air defence to its large sized Vulnerable Areas (VA) like military bases, industrial centres, logistic and administrative areas and nuclear centres. The S 300 (predecessor to S 400) was the weapon system for this role. This system evolved around three verticals, namely P, V and F series. Here, P standing for PVO Stranny (meaning country's air defence), was the mainstay development line for area air defence of ground based strategic assets. V (standing for Voyska or Ground forces) was the compact version of the system basically designed for the mobile air defence cover for mechanised forces, while the F (standing for Float), was the naval version of the system. S 400 is the latest of the P series of the system (also called S 300 PMU 3). The weapon designer is Almaz Corp KB-1 (later Almaz Air Defence Concern) while the Missiles have been designed by MKB Fakel Design Bureau.

Analysing the Technical Muscle of the System

Any ground based air defence system is essentially configured on the three verticals of Sensors, Combat Teeth and Battle Management and Command and Control (BMC2) System. Sensors are for carrying out surveillance of the air space, detecting the air threat, identifying it to be friend-or-foe (IFF) and finally guiding the missiles to the target. Combat teeth are the Surface-to-Air Missiles (SAMs) to take on the designated target while the BMC2 system exercises minute-to-minute control over air defence battle resulting in the delivery of accurate and lethal fire on the intended target. In each of these three verticles, S 400 has many a special features.


The designers of S-400 have laid great emphasis on the initial detection of the incoming threat since it is this one activity, if successfully completed in time, ushers an optimal sequence of air defence engagement. In an entire window of a few fleeting minutes, if this is not done timely, the best of Ground Based Air Defence Weapons (GBADWS) will be rendered toothless. In this context, it is interesting to see how the sensors of S 400 have evolved with time

In the period around early eighties, the air threat at long rages mainly used to manifest from medium and high altitude. Almaz designed an optimal Long Range Surveillance Radar (LRSR), named 36D6 (NATO Codename TIN SHIELD) in the E&F Band (2-3 to 3-4 Ghz) optimised for detection of med/high altitude threat. With a range of 180-360 Km, this radar could track 120 targets at any one time. Moving on towards the late eighties, the air threat, propelled by the growth in aviation technology also started to manifest at low altitude. Since such a threat could go undetected by the LRSR of the type 36 D6 another LRSR 76 N6 (NATO Code name Clam Shell) was developed. 76 N6 is an I Band (8-10 GHZ) radar optimised for low altitude detection. The designers had to lose out on the range of detection in this radar to only about 120 km. This reduction was acceptable as it was considered operationally adequate for tackling a low altitude threat.

As time moved on, the threat of Ballistic missiles started to become live in the air threat hierarchy. To detect Ballistic Missiles at long distances required a lower band radars which were added to the system around the late nineties. This radar was called 64N6 (NATO Codename Big Bird) It was an E band radar that could detect ballistic missiles 1000 km away travelling up to a maximum speed of 10,000 km (2.7 km/sec).This radar was also optimised to detect stealth targets which had just about started to become a reality around the nineties. As technology advanced further, it was possible to combine multiple altitude detection verticals in a single machine. The designers of S 400, came up with an all-altitude detection radar named 96 L6 (NATO Codename Cheese Board) with a high range of 600 Km and a capability to simultaneously detect some 300 targets.

In a further upgrade of the earlier designed radar optimised for the Ballistic missiles and stealth targets (64 N6), the final configuration of S 400 has latest sensor at the cutting edge of the technology called 91 N6 (NATO Codename Big Bird). This radar is the latest 3 D (Three Dimensional) Panoramic Radar that is all-altitude capable besides being optimised for detecting ballistic missile and stealth targets. In addition to carrying our surveillance and initial detection of the target, sensors are also required to track the assigned target and guide the missile towards it. S 400 has a Multifunction Radar (MFR) 30 N6 ( NATO Codename Flap Lid) for this purpose. This compact radar can track up to 12 targets at a time and can guide up to 6 missiles at any one time.

What is Special about the Sensor Package of S 400

From the foregoing following becomes clear:-

  • The weapon designers have laid great emphasis on the initial detection of the threat.
  • The sensors have evolved along with the revamping of the air threat from Medium/High Altitude to Low level, to Ballistic Missile threat to stealth threat and more.
  • The system has a formidable sensor package covering all altitudes and extending to long ranges up to 600 km.
  • It has sufficient capability to simultaneously track any threat by quantum (300 targets).
  • The latest sensors have cutting edge technology features (3D Panoramic/all-altitude detection) and high survivability muscle in the hostile Electronic Warfare (EW) environment.


The most distinctive feature of S 400 is its capability to fire three dissimilar missiles from the same platform with nil/minimal changes on the action stations. The first of the three missiles on board is 9M 96 E with an operational range of 120 Km. This missiles is Active Radar Homing (ARH), which means that it carries its own trans-receiver on board which gives it the capability of finding and tracking its targets on its own. Initially the MFR that is tracking (illuminating) the target keeps guiding the missiles towards it. At a point closer to target the missile activates its own ARH mode in accurately closing on to the target. The probability of hitting the target with a single launch of 9M96E missile is around 90 %.

The second type of missile on board is 48 N6. Flying at an incredible speed of 17280 km per hour (4.8 km per second, Mach 14), it is eminently capable of closing on to the threat much faster than any known threat can move. The missiles features two types of guidance systems, namely, semi active homing (Range 250 km) in which it closes on the target by guiding itself on the signals of MFR getting reflected from the target and Track via Homing or TVM (range 200 km) in which case, the missile remains hidden from the target being attacked, keeping surprise alive.

The third type of missile is an extremely long range missile (400 km). The special feature of this missile is its trajectory which has a high apogee (highest point reached during free flight) in excess of 40 km. It means that upon launch the missile rises high into the exo-atmospheric space thus gaining a lot of Potential Energy (PE). Once past its highest point, it comes pouncing down on the target converting this PE into Kinetic Energy (KE) thus achieving a high kill capability with tremendous acceleration and high G capability. Such a missile is optimal in the anti-Ballistic missile role.

What is Special about the Missiles of the System

  • Three dissimilar missiles capable of being launched from the same platform.
  • Range versatility (120-200-250-400 km) suited for multi-role.
  • Variations in the guidance systems to increase effectiveness and enhance survivability.
  • Many a special features (17280 km per hour, PE to KE).


The BMC2 system automates the entire range of air defence battle functions starting in sequence from the surveillance of air space , detection of aerial targets, identifying them to be friend or foe, building Air situation Picture (ASP) through fusion of inputs coming from multiple sensors, prioritising the air threat based on immediacy and comparative lethality, weapon selection for optimal engagement, target designation to the selected weapon station(s) and exercising minute-to-minute control of air defence engagement. BMC2 system also ensures backward integration of the weapon system with other GBADWS and ensuring optimal resource sharing.

An Idea of Quantum

Just to give an idea, each of the five Regiments being purchased will have 8 Missile Launchers. Each launcher is capable of carrying 4 Missiles in different combinations of the three types discussed above. Besides this, there will be a sensor package and a BMC2 system of the type analysed above. Each Regiment could be deployed singly or in two fire units of 4 Launchers each. Though one set of regimental launchers will be able to carry 32 missiles on board, the total missiles will include quite a number (First Line, Second Line, War Wastage Reserves, and Training aggregates).

Likely Impact of Induction

In order to ward off the type of air threat described above, the current family of GBADWS is conceptually deployed in a layered and tired fashion with multiple weapons providing successive higher ranges and attitude capability covering the chosen grid with an area air defence cover. This family has Terminal Weapons (guns and man portable systems: 3-5 km), Very Short Range Systems (VSHORADS missiles P: 6-10 km), Short Range SAMs (SRSAMs: 15-30 km), Medium Range SAMs (MRSAMs: 70-100 km) and Long Range SAMs (LRSAMs - beyond 100 km).

In the above landscape of GBADWS generally covering an area grid of say 100+ km in range and 15-30 km altitude, the S 400 system with a range capability of 40-400 km and altitude capability from low level to about 56 km, will have the following signatures:-

  • It will be a ‘WAY ABOVE’ system, implying thereby, that the capability of range, reach and kill effects it brings, will be way above anything we have had in the existing Ground Based Air Defence (GBAD) landscape till date.
  • Its backward system integration and resource sharing capability with the existing GBADWS will provide a paradigm enhancement in the existing surveillance, battle management and kill capability of the entire system as a whole.
  • In specifics, as a far upper end of the area air defence system, it will render large swaths of area under air defence cover. These areas could include high value installations, key Govt. institutions, seat of power, important army/naval / air force bases/assets, oil dumps, refineries, nuclear power installations and more.
  • In the anti-missile role the system will integrate with our Ballistic Missile Defence (BMD) Programme named 'Programme AD' under development by the DRDO. This programme, as is known in the open source, is a two tier system providing interception of incoming ballistic missiles in the exo-atmospheric region ( altitude 50-80 km) as well as, endo-atmospheric region (altitude 15-30 km). The Programme is in two phases. In Phase 1 the system capability will be able to take on the ballistic missiles up to the ranges of 2000 Km while in Phase 2, the system capability will be extended to 5000 km. Phase 1 stands operationalised while Phase 2 is nearing completion. S 400 will bring a quantum enhancement in this capability

On the Flip Side

Before resting the case on the capabilities likely to be enhanced, the same must be seen along with the reality of the following hard facts:-

  • While the procurement is through Inter-Governmental Agreement (IGA), the entire procurement procedure is yet to unfold where every step has a time penalty. By any modest guess, the entire cycle could take 3-5 years.
  • The capability enhancement will be incremental as fire units of the regiment get built up over time.
  • The issues of Indian work share and its progressive enhancement, transfer of technology (ToT) and more importantly, its absorption capability by our public and private industry over the years and the entire gamut of ‘Offset’ will be huge challenges, each demanding its timeshare and repeated deliberations/negotiations and more.
  • Associated with the above will be the issues of training, maintenance ToT, Quality assurance and clearances, EMC/EMI clearances, simulators and more.

The two sides of the answer to the media buzz is now stands stated.

Published Date: 3rd November 2016, Image Source:

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