AERIAL THREATS AND AIR DEFENCE: PROMINENCE ON THE GROUND BASED AIR DEFENCE

The Aerial Threat and Necessity for Air Defence

During the American Civil War, in August 1861, Union Forces used a balloon to observe Confederate Forces massing against Washington. Using a rifled 6 pounder, the Confederates fired several rounds at the balloon. They scored no hits but the fire caused the balloon to be brought down. Since the time such balloons were used to observe or throw bombs or other hostile weapons against ground troops, the counter to these actions have always been keeping pace against such hostile air action as its natural fallout. Balloons made way for very sophisticated flying machines, which could cause awesome devastation, and as a counter, the 6-pounder has been replaced by a family of surface-to-air weapon systems consisting of radars, guns and missiles, which when deployed in a coordinated manner, can sanitise an expanse of air space for a particular period of time against unfriendly aerial activity.  Air power and the nature of aerial threat is undergoing a dynamic change. Today, air power no longer connotes manned combat aircraft alone, but is shifting towards the realm of unmanned platforms. The air threat matrix, wherein the use of Beyond Visual Range (BVR) weapons have become a rule rather than exception and is now defined by players like attack helicopters, Unmanned Aerial Vehicles (UAVs), cruise and ballistic missiles, Electronic Warfare, Anti-Radiation Missiles, smart, intelligent and precision guided munitions; and in times to come space based weapon platforms, will dominate the battlefield. Technology has made a cutting edge impact in all facets of air power, transforming it into an aerospace power. Therefore, not only is there a crying need for land based air defence of the country's air space but also the need for integration of effort in terms of management and employment of all air defence resources. Air defence, at the national level, necessitates an overall integrated approach in order to perform its intended role. In India, although Indian Air Force is overall responsible for air defence of the nation, the army, navy and the air force have their own air defence branches with weapons which fall under the operational control of the Indian Air Force. 

Requirements for Air Defence

The ground, air and naval combat forces must be allowed maximum freedom of manoeuvre and therefore, must be able to ensure that multiple aerial threats in a particular geographical area is taken care of in the short span of a few seconds available for engagement. Therefore, there is a requirement for shifting layers, mobility, varying ranges to provide flexibility in air defence. These layers will also have to be tiered to provide multiple punishment at area and point defence levels. Air defence will also have to be lethal and capable of engaging at enhanced ranges with a mix of guns and missiles with added capability of handling multiple targets. These measures should also be able to have a networked grid of long and medium range surface to air missiles (SAMs) facilitating plug and play operation to provide area air defence cover to all assets. The system must also have a modularly designed identification of friend and foe system which can be compatible with all users of air space to prevent fratricide. It must be able to have gap free surveillance and ability to act against non-state actors, capability against unconventional measures and finally an apex organisation for consolidated control of all air defence assets and seamless integration with theatre missile defence. Having all these in the air defence organisations would naturally make such organisations complex and consequently more expensive. It would therefore, be prohibitive for any country to have state-of-the-art air defence always and every time. Therefore, the solution has to be a judicious mix of different technologies with updation and upgrades. 

Layers of Air Defence

As mentioned earlier, air defence has to be layered and tiered to ensure that its assets in terms of static, semi static and mobile assets survive aerial threats. The outermost layer is usually provided for by the air force in terms of interceptors supplemented by long range Surface to Air Missiles (LRSAMs). These are additionally buffeted with Medium Range SAMs (MRSAMs), Very Short Range Air Defence Systems (VSHORADS) and finally the close in weapon system (CIWS) constituting rapid firing guns with programmed ammunition or a mix of guns and missiles as per importance of the assets being protected. The LRSAMs have a chain of radars and control system providing early warning information. These are deployed to ensure that the air threats are taken care of at the longest distance. Similarly, the navy also has its concentric air defence or defence in layers with various types of ships each of which has various air defence weapons of different ranges and capability. Land-based Phalanx Weapon System (CIWS) is part of the US Army's Counter Rocket, Artillery and Mortar systems used to detect and destroy incoming rounds in the air before they hit their ground targets. It also helps provide early warning of attacks. Therefore, it is important that we need to have a look at what is available in all these segments with a particular interest to the available air defence equipment in our neighbourhood.

Point Air Defence

         Point air defence can be explained as the measures adopted to provide air defence of a single object or a small area, e.g. a ship, bridge, building or an airfield usually against aerial threats. These weapons have smaller range, greater flexibility and within the sight of the vulnerable point that it protects.  The point air defence is generally provided with close-in weapon systems on ships and airfields or a mix of land based very short SAM systems for example a combination of Polish Loara or Rheinmetall Skyshield gun system with AHEAD ammunition alone or in combination with man portable missile systems like RBS 70NG, Stinger or Igla S. These are cheaper compared to long range complex air defence missiles and are well suited to provide terminal stage air defence both against aircraft and helicopters as well as against mortars and missiles too. But such systems will have to be deployed in all important points where there is an aerial threat. There is a school of thought propagating that “there is no need for guns in the modern air defence arsenal and all guns need to be replaced with missiles”. What is required is that the final stage of air defence or point defence or the final CIWS should be a gun-missile mix to incorporate all the advantages of the non jammable guns. Today, many countries have the outdated L70, Zu-23 twin barreled and Zsu-23 Schilka guns which need to be replaced with more efficient guns systems like the Skyshield, Loara, German Mantis system and their self-propelled counter parts like Gepard, Tunguska M1, Pantsir or the South Korean Doosan systems. The gun systems are generally to engage in the range of 4 to 6 km and the missiles in the range of 6-10 km thus providing two layers of defence against aerial threats. In fact, the Russian Tunguska and the Pantsyr are gun missile systems mounted on single combat vehicle and can be very effective against low flying aerial threats in the mobile battle field. 

The Pakistani point air defence consists of limited quantities of modern radar controlled 35 mm Oerlikon guns with Skyguard radars and RBS-70 SAMs with Giraffe Radars in this segment. These are deployed to protect vital installations and air assets. Similarly the mobile assets get point air defence from a weapon mix of optically laid, manually controlled 37 mm, 14.5 mm guns and RBS-70 missiles mounted on APC M-113. Apart from this, the Pakistani army air defence also deploys older version shoulder fired infra-red (IR) or laser beam riding missiles like SA-7, Redeye, Chinese made HN-5, indigenous Anza or US made Stinger missiles independently or along with a number of 14.5mm Guns to protect a point. 

            The Chinese People’s Liberation Army (PLA) air defence however, has much better equipment in terms of quantities for point air defence. The PLA uses a mix of guns and short range SAMs or two varieties of SAMs for point air defence. In terms of guns the PLA has towed 57mm and twin barreled 37mm guns. The gun missile mixes are mostly vehicle or track based. The Type 95 system has CLC-1 search radar with four 25 mm guns mounted on the vehicle along with four QW2 heat seeking missiles. Along with this, they have CLC-2 search radar based on a separate vehicle. The system has been developed to bring about an equivalent of Russian Zsu-4 Schilka weapon system.

Next in line is the latest 8x8 vehicle version called Lundun 2000 which has a Type 730B gun considered to be a copy of the Goalkeeper 30mm CIWS and is also thought to be a copy of the Avenger gun used on the US A10 aircraft. Recently, an addition of six TY90 SAMs is aimed at equating it to Russian Pantsyr in terms of role. The system is equipped with a counter rocket, artillery and munition (C-RAM) role by the PLA. There is a Type 90 variant of the 35 mm guns initially licensed by Oerlikon which has been made into a radar controlled guns system with good mobility by adding a heavy mobility vehicle and a Type 902 radar system. Similarly, the Chinese are reported to have been able to clone the Crotale SAM in their latest version called HQ7B/FM 90 based on a 6x6 vehicle with the missiles reported to have a range greater than 10 kms. The HQ6/HQ61 again is employed as point defence SAMs. These have now been improved to LY60/HQ64 system which is reported to be a clone of Italian Selenia (Alenia) Aspide MkI SAM system with greater range of upto 20 kms. A copy of AN/TWQ- 1 Avenger of US is thought to be the FB6A system which again uses TY90 SAMs. Then there is the LS II AD system (Lie Shou ‘Hunter’) with a mixed missile armaments of two SD-10/PL-12 and two PL-9C SAMs. The system again is based on a heavy mobility vehicle with a search radar, electro optical system and a laser range finder. Other point defence systems with the Chinese PLA are FLV-1/FLG-1/FL 2000 wheeled air defence system with QW1A lightweight SAMs, Yi Tian WZ551 wheeled system with short ranged SAMs (TY90 variety) with a range of upto 6 km and then there are the shoulder fired SAMs like QW2 and FN 16. Thus, the Chinese have based their point defence based on mobile components made out of radar controlled guns, very short ranged and short ranged SAMs. The quantities are thought to be adequate but the efficacy is something which needs verification.

Short Range or Medium Range Area Air Defence

The next tier in air defence is termed as short range and depending on how the nomenclature with respect to range is used, some may even classify this in the category of medium range air defence. The short range is generally in the range of 20 to 30 km with a height of 3-4 km and medium range extends upto 50 km. There could be various versions of these with high mobility versions mounted on high mobility vehicles like Tatra, Tata or Ashok Leyland 8x8 vehicles or could even be mounted on tracked chassis.

Indigenously produced by DRDO, Akash, is the most modern version of this type of missile system now with the Indian Army and Air Force. Such systems are a complex combination of radars which carry out electronic scanning and provide information known as air situation picture to the next level of radars which are tracking radars. These continue to track the targets assigned to them and even guide the missile from their launchers to destroy the tracked targets. In the short range variety, the common ones that are available are Tor M2K (successor of the versatile OSA-AK) and Pantsyr system (without gun version) of Russia, MBDA manufactured SPADA 2000/ASPIDE 2000 missile system which is a ground based missile system capable of operating in dense ECM environments to provide all weather area defence against combat aircraft and incoming missiles. Another important system from the Israeli stable is the remodeled air to air missile Derby and Python by Rafael which makes a combination of these missiles into a system called SPYDER.  The SPYDER (Surface-to-air PYthon and DERby) is an advanced ground based anti-aircraft missile system that uses surface-to-air versions of the Python-5 and Derby missiles. The Swedish company Saab is also a player in this segment with their BAMSE missile system and Giraffe surveillance radar. The National Advanced Surface-to-Air Missile System (NASAMS) of Raytheon is a highly adaptable mid-range solution for operational air defence requirement. The system provides a tailor-made, state-of-the-art defence system that can maximise their ability to quickly identify, engage and destroy current and evolving enemy aircraft, UAV or cruise missile threats.

Two missiles come to mind in the medium range variety: the Russian Buk (beech tree) System owing to the alleged role of the equipment as reported by the media in the infamous case of downing of the Malaysian Airplane over Ukraine in 2014. In true terms it was developed as the successor of Kvadrat and Kub missiles. The Israeli Barak 1 converted to Barak 8 (lightning) is one of the most modern MRSAMs. The missile is mounted on mobile vehicles and is vertically launched active seeker missiles. These translate into actual fire and forget capability with multiple engagement scenarios and capability for the user. These systems are generally deployed in a fashion so that an area is provided with ground based air defence and can be also called as area air defence. In easy to understand terms, the area air defence assets cover may have a variety of point air defence weapon systems in the given geographical area depending upon the time and importance of the assets that these weapons are protecting.

In 1998, the China National Precision Machinery Import and Export Corporation (CNPMIEC) produced an improved HQ-7 with faster and longer-range missiles, with an IR-tracking camera. This version received the export designation FM-90 which is thought to be the reverse engineered version of the Thomson-CSF Crotale missile. This is the missile system that Pakistani air defence has recently procured. Apart from this, the Pakistani army air defence is not known to have any other short or medium range SAM.

Till the early nineties, Chinese air defence was being catered to by SA-2 SAMs and J-8 fighter aircraft. However, the Chinese have been reportedly moving ahead with area air defence steadily post the breakup of the Soviet Union. Presently, most of their SA-2 have been modernised and are present in numerically significant numbers. China has also been thought to have the Russian Tor M1 (SA-15) with indigenously produced derivatives like HQ-9/HHQ-9/FD2000/FT2000. The FT 2000 is reportedly a derivative fitted with anti-radiation seeker for engagement against AWACS aircraft and against standoff jamming aircraft. HQ-9 is likely to be using the Russian S-300PMU technology including cold launch design for vertical ejection. It probably would fall under the MIM-104 Patriot category in terms of performance. The system has phased array radar based on a heavy mobility 8x8 vehicle and claims to operate in C band with ranges upto 125 km. HHQ-9 is the naval version of the SAM. HQ-12/KS-1A of PLA compares at best with US built RIM-66 SM-1/SM-2 standard SAMs in terms of capability. This system is to replace the now upgraded and hybridised HQ-2 and has a maximum range of 50 km with 27 km of altitude capability. Also, very little is known about HQ-16/SA-11 (Gadfly) which probably is a joint version of PLA and Russia for area air defence.

Long Range Area Air Defence and Anti- Ballistic Shield

Air defence SAMs have to cater for the long range and standoff missile threats which have now acquired serious proportions. The long range precision guided missile fired from standoff ranges upto 100 km have gone beyond the capability of short or even medium range SAMs. Therefore, air defence requirements now commences from taking on the threat at longest ranges and against the ballistic missiles which can travel across continents and pose credible threat. The systems which cater to these include the S400 (Triumf) of Russia or Project Nike of US. Apart from these the extended range Barak and the famous Patriot may also be considered in this category. S400 missile system is the most modern and has been in the news recently for its deployment in Syria and also the acceptance of necessity being granted to procure them for the Indian Air Force. The Russians deployed the first of the S400 to protect Moscow in 2007 as part of Aerospace Defence Forces.

The system was developed as an improvement over the S300 as it would help the countries develop capability against standoff attacks. The S400 is highly flexible when it comes to engagement ranges. The system uses multiple types of interceptors based on the targets range. The S-400 command node can bring down the very long range target at 400 km, at 250 km, at 120 km and also at a medium range of 40 km too. The big interceptor S400 missiles (which are understandably harsher on the pockets) need not be used on targets flying closer and can be reserved to harass slow moving, high value targets (like AWACS, Fuel tankers, transports, etc). The Russians find this approach of arming a single system with multiple interceptors most suitable for their needs. In comparison, Patriot is a long-range, high altitude, all-weather solution that has been rigorously tested more than 2,500 times with US Army oversight under real-world conditions. It can counter threats from tactical ballistic missiles, cruise missiles, drones and advanced aircraft. Today, China has formidable long range anti-ballistic SAMs like Russian S300 PMU-21 heavy mobility system to provide modern, multi layered integrated air defence systems.

Future Trends

Air defence is a concept which has to be primarily coordinated and carried out at the highest level and therefore, in India the overall responsibility of air defence is with the Indian Air Force. Although, the air force, navy and the army have its own integral air defence equipment, the operational control is with the Indian Air Force. Some countries like Russia have separate air defence commands and Pakistan even has an Army Air Defence Command headquarters (HQ). Air defence is a complex business but there is a trend to simplify the systems. The complexity is owing to the fact that the aerial threat has changed from fixed wing aircraft not only to complex ballistic missiles but also to drones which have varied ranges and speeds. Therefore, one single system cannot cater for all these varied aerial threats. The situation is so potent that even ammunition has become an aerial threat vehicle. The complexity multiplies owing to the need of not only destroying or limiting the aerial threats but allowing self-owned aerial threat vehicles to utilise the same air space to destroy the enemy’s assets.  Therefore, the need for an integrated system which would have Command, Control, Communication, Computers and Intelligence (C4I) sub systems, detectors and sensors which will control the weapons.

In terms of guns, the future would be of systems which have unmanned and remotely-controlled turret with integrated ammunition feed. These will ensure better reaction time and reduction in crew, multi-weapon platforms with guns and missiles on the same platform to provide multi-layered defence and improved kill capability. The need for locating fire control systems on the weapon platform for shorter reaction time, provision of mobility with high mobility vehicles and high rate of fire with multi-barrel guns having independent breech blocks. In the field of ammunition, trends like advance hit efficiency, where muzzle velocity is calculated for each round and time to the target, is fed in the precision fuse resulting in the shell exploding at optimum range to create a sub projectile cloud is already a trend.

In case of SAMs, the integrated air defence for point defence and area air defence in a grid fashion with plug in and plug out facility would be required if a system cannot cater alone for the various threats at various ranges. Even the S400 system which has a variety of interceptors for destruction of variety of targets at various ranges has Pantsyr system to provide close protection against suddenly appearing helicopters which could target the S400 radars or missile launchers. A mobile grid, if resources are adequate, is one of the best ways to employ air defence resources adding to flexibility and creating a theatre grid. Such a grid would then be able to also support manoeuvre forces and strategic assets. Multi-layered deployment to cater for vertical and horizontal aerial threats thus catering to air defence of high altitudes from low and very low altitudes is another modern trend. The deployment has to be in a layered and tiered manner and have to be time and area specific for best results. Israeli air defence with Arrow3, Arrow2, David’s Sling and Iron Dome is one such example catering for the upper and lower layers respectively. There is a great need for all air defence command and control elements to be networked so that the process of  gathering, fusion and dissemination of information to permit the real or near-real time tasking, control, integration and co-ordination of maritime, land and air force AD capabilities. The communications architecture should have sufficient capacity, security, jam-resistance and survivability to accommodate information exchange between all levels of command and control, including the capability to transmit operationally-essential information within a degraded communications environment. Voice and data link are primarily required in air defence for the task of communication. Tactical data links have evolved to meet critical real-time and near real-time information exchange requirements, with particular significance for air defence operations.