Challenges of Integrated Air Defence

Air Defence Systems around the world

On 27 February Indian Air Force (IAF) was engaged in active combat thwarting the Pakistan Air Force (PAF) riposte to IAF’s Balakot strikes on 26 February. PAF had launched a 24 aircraft force offensive strike mission against India in Jammu and Kashmir sector. Indian air defence aircraft and weapons which were on a high alert engaged the strike and prevented them to cross the Line of Control (LoC). In the melee, Wg Cdr Abhinandan while piloting a MiG-21 Bison, chased a PAF F-16 and shot it. Simultaneously he was shot either by a PAF F-16 or by Paksitani ground fire and had to eject in Pakistan occupied Kashmir (PoK).  At around the same time one IAF Mi-17 V 5 helicopter was reportedly shot down by an IAF’s air defence missile. Both these incidents brought to question IAF’s air defence capability and also the integration of the Air defence Systems.  

IAF’s MiG 21 Bison. Picture Source: http://www.indiatoday.in (Getty Photo)

The Mi-17 V 5 Accident.

The Mi-17 V-5 helicopter was on a routine flight in the local flying area (LFA) of the Srinagar airbase. The  Israeli origin Spyder air defence system was deployed to protect the airbase. The air defence radars at Srinagar airbase had picked up a low flying aircraft on their screens. The senior officer manning the post of Terminal Weapons Director (TWD) reportedly gave the final order to fire after the helicopter, designated a slow flying target, could not be identified through the Identification, Friend or Foe (IFF) transponder. The system is meant to ensure electronic recognition of friendly aircraft. A ‘no electronic response’ could be viewed as unfriendly. An unserviceable IFF or in case it was switched off could also create such a situation. Normally there are procedural safe guards to cover such eventualities. The helicopter was in radio contact with ground controllers moments before it crashed. The chopper did not deploy any countermeasures as it did not perceive any threat in the area and received no warning before the missile was fired. The helicopter had not been designated a ‘Red’ target by IAF’s Barnala-based Integrated Air Command & Control System (IACCS) that is tasked with monitoring incoming aircraft from Pakistan. The order to fire was issued, perhaps because the target was perceived to be an incoming Enemy unmanned aerial vehicle (UAV). At the time of the PAF air raid, ideally, the helicopter should have been kept in a pre-designated safe funnel meant for friendly aircraft instead of it being called back to the base, more so, if the Air defence guns and missiles have been designated “free to engage”. As per prevailing Standard Operating Procedure (SOP), all aircraft were to have their IFF systems on. Had the IFF system been on, air defence radars would have at least identified Helicopter as friendly. While the full details will come out only after the Court of Inquiry is finalised, the accident, in which seven lives were lost, has put into focus the need to revisit the subject on integrated air defence, more so in conditions of ‘Fog of War’.

IAF’s Mi-17V-5 Military Transport Helicopter. Image Source: http://www.airforce-technology.com

Air Space Control 

Air Space Control (ASC) refers to regulating the use of air space by multiple users. The need for regulation arises because of finite resource of ‘air-space’. From military operations’ point of view, the objective of airspace control is to maximize the effectiveness of combat operations without adding undue restrictions and with minimal adverse impact on the capabilities of any component. The emphasis is on close coordination that must exist between airspace control, air traffic control, and area air defence units to reduce the risk of fratricide and balance those risks with the requirements for an effective air defence. The balance required between restrictions on ASC and flexibility has to be jointly determined and evolved.

Typical Tactical Battle Area (TBA). Image Source: http://www.spslandforces.com

During conflict, the air activity in the Tactical Battle Area (TBA) is extremely dense. Both friendly and enemy aircraft are transiting. Horizontal and vertical airspace is not only fully covered but variations in time and space are dynamic.  Most flights are launched at a very short notice based on evolving tactical situation. There are fast moving jets, slow moving helicopters and many UAVs. Also occupying the airspace are high velocity long and medium range artillery shells and a variety of missiles. Ground based air defence weapons are on hot standby, and some operated from remote locations close to the forward edge of the battle area (FEBA). There is therefore a need for quick timely information sharing. There have to be clearly designated agencies for direct and procedural control.  

Air Defence Elements 

The fighter-bomber aircraft remains the main instrument of prosecuting air war and conversely also for air defence.  They create air superiority for unhindered operations of surface forces. Fighters strive to have ‘first-look, first-shoot, first-kill’ ability.  Other significant airborne platforms that support air operations are the airborne early warning and control systems (AEW&C), electronic warfare platforms and aerial refuelers.  Each of the armed forces has surface-to-air missiles (SAM).  These could be long to medium range or short-range systems including man-portable shoulder-fired ones. ASC allows freedom of action to air defence elements and yet avoids fratricide.  All services have their own aerial platforms and AD elements. There is thus a need for air space coordination, especially in the TBA and over the sea when air force elements are launched in support of naval operations.  

IAF’s DRDO Embraer AWACS aircraft (image: Rushabh P Bafna). Picture Source: defenseworld.net

Permeation of UAVs

Fast permeation of UAVs has brought in a new challenge for ASC. UAVs are now even being allowed in the national airspace system (NAS). If UAVs have to cohabit the finite air space with manned aircraft (civil and military), then there is a need to address the looming danger of a collision. Even in military UAV roles now are much beyond the traditional reconnaissance, surveillance and target acquisition (RSTA). They are used in electronic warfare (EW), deception operations, nuclear cloud surveillance, and host of other military applications including the teaming of the manned and the unmanned vehicles in joint operations.  

Boeing Unveils Fighter Drone that Could Play Wingman to Manned Jet. Image: Boeing

Airspace Control Methods 

ASC coordinates, integrates, regulates activities in the defined airspace by identifying and monitoring all airspace users. Integration is the key. Regulation is required to supervise activities in the airspace and provide for flight safety. Timely identification allows early engagement of enemy aircraft and also preventing potential for fratricide. ASC measures and procedures are disseminated to all airspace users and control agencies. Essentially, there are two means to exercise control – Positive control and Procedural control. Positive control relies on positive real time identification and tracking. It is conducted using radars; identification, friend or foe (IFF) interrogators and receivers; beacons; computers; digital data links; and communications equipment. Positive control facilities are subject to attack and sabotage. They may be restricted by line of sight coverage, electronic interference, and limited communications. Procedural control relies on previously agreed and promulgated orders and procedures. Procedural control divides the airspace by volume and time and uses weapons control statuses to manage aviation operations. It is less vulnerable to interference by electronic and physical attack and ensures continuity of operations under adverse environmental conditions. It also serves as a backup system if positive control is lost. 

What is IFF (Identification Friend or Foe)? Image Source: everythingrf.com

Unity of Control

Air space command and control requires unity of control for the myriad actions performed by the various military elements. IAF being the designated service for air defence of India, has overall responsibility. ASC builds a comprehensive picture of the battle-space using the sensors with the three services and civil radars. IAF’s tactical air elements with the Indian Army and Navy support coordination between the services. Agencies and individuals that perform air control functions include the—Tactical Air Center (TAC) and Maritime elements of air force (MEAF) and the early warning and control radars. Designated controllers and coordinators perform air control functions by directing subordinate elements.

Layered Air Defence

Air is a complex medium.  Air defence of a vital asset or an area is normally built around a system of concentric layers.  The outer layer is usually handled by fighter aircraft with active electronically scanned array (AESA) radars and combinations of AD missiles, supported by AEW&C.  If an attacker is able to penetrate this layer, then the next layers would comprise of SAMs. The area-defence missiles could have ranges in excess of 150 kilometres. The S-400 Triumf class which has a family of missiles covering different height and range bands could neutralise targets at 400 km. Other shorter range missiles would have ranges around 30-50 kilometres.  Finally, there will be the close-in-weapon-system (CIWS), the very short Range AD system (VSHORADS) missiles, the man-portable missiles and the radar controlled anti-aircraft guns firing several thousand rounds per minute.

Typical Layered Air Defence. Image Source: webmaster-studio.info

Surface and Airborne Radars

Ground-based radars are an important element to manage both air threat and ASC. High and medium powered surveillance radars, tethered aerostat radar balloons, missile acquisition and guidance radars, tactical battlefield mobile radars and ship-based radars are all part of  the ground sensor network.  Air Traffic Control (ATC) radars and controllers perform a significant role in airspace management.  The airborne early warning and control (AEW&C) system is an airborne radar picket system designed to detect aircraft, ships and vehicles at long ranges and perform command and control of battle-space and air engagements by directing fighter and attack aircraft strikes. It also helps the operators to detect and track targets and distinguish between friendly and hostile aircraft much farther away than a similar ground-based radar. Because of its mobility, it is much less vulnerable to counter-attack, though it will be targeted by enemy fighters and missiles. 

Typical Tethered Aerostat Radar. Image Source: aerohistory.org

Air Space and Fire Support Coordination

A critical part of ASC is to outline hostile criteria for identifying targets and coordinating fires. The ASC area is laterally defined by the boundaries of  component’s area of operations. Air control points are designated separately for Entry/exit, en route, Orbit/holding, Contact point, Rendezvous, Egress control, Penetration, Ingress, and Return. Friendly aircraft en route to and returning from combat missions need to avoid enemy air defence systems yet be visible to friendly air defence systems. The points must be easily identified from the air and support the ground tactical force scheme of maneuver. Fire support coordination allows opening areas of the battle space for rapid engagement of targets. In the air defence action area friendly aircraft or surface-to-air weapons are normally given preference to conduct air defence operations. 

Typical Electromagnetic Environemnt in Battle Space. Image Source: http://www.japcc.org

Weapons Control and Coordination 

Decentralized control (freedom to fire) is the normal wartime mode of control. Even under centralized control, the right of self-defence is never denied to any element. An air defence identification zone (ADIZ) consists of airspace that requires ready identification, location, and control of aerial platforms. Typically, an ADIZ is used for sovereign national boundaries, and also in areas of operations. Freedom is given to fighter aircraft or SAMs where ever they have clear operational advantage over the other. The base air defence zone (BADZ) is an air defence zone established around an air base and limited to the engagement envelope of short-range air defence weapon systems defending that base. Emission control (EMCON) regulates the use of electromagnetic, acoustic, and other emitters to optimize command and control capabilities, thus minimizing the detection of assets by enemy sensors and reducing mutual interference among friendly command and control systems. 

Some of the Technologies and Concepts tested in UTM Research and Development.
BVLOS (Beyond Visual Line of Sight); C2 (Command and Control); DSRC (Dedicated Short-range Communications; FIMS (Flight Information Management System); Remote ID (Remote Identification); USS (UAS Service Supplier). Image Source: utm.arc.nasa.gov

Airspace Control and Technologies 

Air defence interface is critical to effective combat zone airspace control. Communications data-link architecture enables this process. Timely, tailored and fused intelligence is integral to all operations. The sector air defence commander is responsible for air defence warning and weapons release conditions, launching Operational Readiness Platform (ORP) aircraft or diverting airborne aircraft to attack time-critical targets. He provides positive airspace control, surveillance, en route air traffic control and navigational assistance for friendly aircraft. He also provides close, broadcast, tactical or data-link control to all missions. He also provides early warning and cueing to surface-to-air weapons units within the BADZ. Command and control systems are susceptible to electronic attack (jamming) and electronic warfare support (deception, intrusion, and interference) operations. Among the technology requirements are the primary and secondary radars for control and situational awareness, aircraft transponders, flight data processing systems, special software for fully automated systems and conflict alerts and algorithms for possible vectoring solution. Controller pilot data link communications and operational data links (ODL) allow digital messages to be sent between platforms and ground system. Artificial Intelligence (AI) has great scope for ASC. Intelligent machine systems can interpret complex data, perceive the environment and support appropriate actions. Yet the world needs to resolve the technical issues related to IFF equipment.   

Indian Military Air Space Coordination

In the TBA, the enemy air tries to engage our surface forces. Similarly, the IAF will support the Indian Army through air operations.  There will be many joint or special operations. Between the Indian Armed Forces, the domains are clearly demarcated.  The Army manages the surface coordination, the Navy manages the maritime picture and the Air Force coordinates the ASC.  The air defence of the nation is the IAF’s responsibility. The air defence of the Army and Navy’s integral assets is their own responsibility. The big situational air picture is created by the IAF using its own, civil and other services radars.  Such a picture is made available at the TAC level to the Army and at the MEAF level to the Navy.  The air defence clearance for all air movement is given by the IAF. Very low flying army air assets within a small bubble of air space do not require any clearance but the flight information has to be digitally communicated. Similarly inter-ship naval helicopter flights are managed by the Navy. All flights within the ADIZ require IAF air defence clearance.  Naval flights beyond the ADIZ are managed by the Navy.  IAF attack and support aircraft flying in support of the Indian Navy beyond the ADIZ are coordinated by the Indian Navy. Such coordination is very necessary to avoid fratricide.  Any hold-fire order passed by the IAF would be for short durations over a small geographical area so that full-scale operations of the Army/Navy are not hampered.  Low-level routing of IAF aircraft through the TBA is normally through points in joint knowledge.  The IAF aircrew acting as forward air controllers (FAC) also support ASC at the tactical level.  There is interface between the IAF and the Army at Corps HQ and Command HQ levels to iron out day-to-day issues and jointly monitor the progress of battle.  Similarly, air elements operate with the Indian Navy. The IAF is in the process of aligning the ASC function through its Integrated Air Command and Control System (IACCS) designed for controlling and monitoring air operations by the Air Force at the strategic and tactical levels. The ASC organization also takes in its fold the civil aviation with detailed and institutionalized tie up between the IAF and the Directorate General of Civil Aviation (DGCA). Terrorists in the air is a real threat. While response to the threat would be conventional, better surveillance, policing, and prevention of weapons going into their hand is more important. Air defence procedures have to be tailored to tackle possible rogue aircraft manoeuvres at short notice. 

IAF’s Integrated Air Command and Control System (IACCS). Image Source: thestorypedia.com

Challenges and way Ahead

The cockpit will be ‘information rich’ and it will be critical that we ensure the integrity and security of data. Human-computer interface will be crucial. For emerging powers like China and India, the big challenge is to get all the agencies and systems to switch to newer technologies together.  The TBA will have very accurate lethal weapons.  The air traffic and projectiles in TBA will be both dense and dynamic. Sensors are becoming more accurate and now allow a very realistic day and night all weather, 3-D situational picture to manage the airspace more efficiently. AI will support the human controller for quick decision making. It will give greater freedom of operation to all operators. The hold-fire orders will get minimized in time and space. De-confliction will be automatic and continuous in real-time. Networks will allow the control centers to be secure and placed at long distances from the fog-of-war. Technology will allow civilian pilots and military aircrew greater freedom to choose flight paths and diversions even in real-time. More and more UAS will have to be controlled or ordered through data-links. Cyber security will have to ensured. Procedural back-ups will have to remain in place. The technologies are evolving very quickly. It is imperative for any emerging nation to move with the times. Till such time that more automated systems are in place, training will be imperative to ensure that those at the sharp end of the stick are able to perform their functions to ensure the highest level of air space control to not only challenge an intruder, but more importantly, to avoid any blue-on-blue kills.

This article was published in Indian Military Review (IMR).

Image Credit: Defense Talk

Published by Anil Chopra

I am the founder of Air Power Asia and a retired Air Marshal from the Indian Air Force.

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