Air Space Control – Challenges and the Way Ahead

anil chopra, air power asia, Aerospace, Contrl,

The action in air and space continues to increase. The friendly and adversary platforms and projectiles are not only increasing in numbers but are also travelling at speeds many times faster than sound. Civil traffic is also increasing manyfold. Air space is a finite resource. It thus becomes imperative that appropriate control is exercised for efficient operations, freedom of action, safety, and prevent fratricide. Air Space Control (ASC) refers to regulating the use of air space by various users. From a 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. It is about close coordination that must exist between airspace control, air traffic control, and area air defence units to balance the risks with the requirements for effective air defence. Detailed engagement procedures provide maximum flexibility and responsiveness.

Military Radar Picture. Image Source: Pinterest, Saved by Jeannie Nelson

            During the 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 very short notice based on evolving tactical situations. There are many Uninhabited Air Systems (UAS). 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). The civil air operations have to be allowed to continue albeit with small restrictions and regulations in time and space. There is, therefore, a need for faster timely information sharing. There have to be clearly designated agencies for direct and procedural control. 

Tactical Battle Area (TBA). Image Source: spslandforces.com

Unity of Control

          Air Space command and control requires unity of control for the myriad of actions performed by the various military elements. It requires qualified people, information, and a support structure to build a comprehensive picture of the battle-space. Other field elements provide planning resources. Indian Air Force’s (IAF) tactical air elements with the Indian Army and Navy support coordination between the services. Several types of control exist that can be used exclusively or combined to achieve the desired degree of autonomy in operations. Control could be through close control of an in-flight aircraft, or surface-to-air weapons unit to engage/disengage targets for a specified period. Control could be also procedural.  

Typical Electromagnetic Environemnt in Battle Space. Unity of Control: Image Source: Joint Air Power Competence Centre

Agencies and Individuals

          Agencies and individuals that perform air control functions include the Air Defence Control Centre, Tactical Air operations Centre (TAC) and Maritime Elements of Air Force (MEAF). They use radars and secure communications. Designated controllers and coordinators such as tactical air coordinators (airborne), assault support coordinators, forward air controllers (airborne and on-ground), air traffic controllers, radar controllers, information communications technology managers, the aircraft flight leader, and surface-to-air weapons units are involved.

Indian Air Force Air Traffic Control Centre. Image Source: dharmakshethra.com

Airspace Control Methods

Integration of the elements is most important. The control is either positive or procedural. Positive control relies on 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. All these facilities are subject to attack and sabotage. They may be restricted by a line of sight coverage, electronic interference, and limited communications. They thus require backup procedures to compensate for the failure of part or all of their systems. Procedural control relies on previously agreed upon and promulgated orders and procedures. Included in these orders and procedures are ASC measures, fire support coordinating measures, and air defence control measures. 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 attacks and ensures continuity of operations under adverse environmental conditions. It also serves as a backup system if positive control is lost. Usually, procedural control is implemented to cover positive control limitations.

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

Air Defence Layers and Engagement Options

          Air defence of a vital asset or an area is normally built around a system of concentric layers.  The outer layer will usually be 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 layer is covered by surface-to-air missiles, some with 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 as far as 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.

S-400 Triumf . Image Source: European Security and defence

Surface and Airborne Radars

          Ground-based, 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. These radars can detect threats at various levels. Some are transportable. Many are three-dimensional or provide a panoramic picture. They have ECCM to protect against jamming. There are also over-the-horizon radars that support anti-ballistic missile operations. To cater for the stealth aircraft threat, countries are developing very long-range L, UHF and VHF wavelength radars.  Air Traffic Control (ATC) radars and controllers perform a significant role in airspace management. 

The airborne early warning and control (AEW&C) system are 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.  Because of its mobility, it is much less vulnerable to counter-attack, though it will be targeted by enemy fighters and missiles. There are also a large number of helicopter AEW systems.

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

Procedural Airspace Control

          Air control points are earmarked on the ground for aircrew to route to their targets. These must be easily identified from the air and support the ground tactical plans. These are promulgated through the daily orders. Air control points can be designated separately for Entry/exit, En route, Orbit/holding, Contact point, Rendezvous, Egress control, Penetration, Ingress, and Return. The procedures allow friendly aircraft to move safely throughout the TBA by utilizing predictable flight paths. Inter-service aviation operations could be based on coordinating altitudes to create buffers.

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

Fire Support Coordination

               Fire support coordinating measures allow a commander to open areas of the battlespace for rapid engagement of targets or to restrict and control fires. Permissive fire support facilitates the attack of targets. Restrictive fire support measures and no-fire zones safeguard their own aerial platforms. The air defence action area and the airspace above it are areas within which friendly aircraft or surface-to-air weapons are normally given preference to conduct air defence operations.

Joint Fires Coordination. Image Source: semanticscholar.org

Air Defence Identification Zone

               An air defence identification zone (ADIZ) consists of airspace of defined dimensions that require ready identification, location, and control of airborne vehicles. Typically, an ADIZ is established in sovereign national boundaries or in an operational area. It ensures to minimise mutual interference between air defence and other operations. It may include one or more air defence areas, ADIZs, or firepower umbrellas.

ir Defence Identification Zone. Image Source: Twitter @indiainpixels

Weapons Engagement Zones

The weapons engagement zone (WEZ) is the airspace within which the responsibility for engagement normally rests with a particular weapon system. These include fighter engagement zones (FEZs), various types of missile engagement zones (MEZs), and joint engagement zones (JEZs). The size of WEZ depends on specific weapons system capabilities. The FEZ is normally promulgated when fighter aircraft have a clear operational advantage over surface-based systems. Surface-to-air missile systems will not be allowed to fire weapons into a FEZ unless targets are positively identified as hostile, identified and/or assigned by a higher authority or firing in self-defence. In MEZ the responsibility for engagement normally rests with missiles. MEZs are divided into high-altitude and low-altitude MEZs. In a JEZ, multiple air defence weapon systems are simultaneously employed, and correct differentiation between friendly, neutral, and enemy aircraft is required. The base air defence zone (BADZ) is established around an airbase with short-range air defence weapon systems. A vital Area is a designated area or installation to be defended by air defence units. Vital areas include airfields, command and control systems, Signal units, GCI units, and some other command elements. Emission control (EMCON) regulates the use of electromagnetic, acoustic, and other emitters to optimize command and control capabilities. EMCON also aids in executing a military deception plan.

Weapons Control and Coordination

It is an endeavour to achieve decentralised control of assets, to allow maximum flexibility to attack or counter aircraft and missile threats. Centralised control occurs when the controlling agency directs target engagements. Even during centralised control, the right of self-defence is never denied. During decentralised control, controlling agencies monitor so ass to prevent simultaneous engagements of the same hostile threat. Decentralised control increases the chance of engaging a hostile aircraft in a high-density environment.

Image Source: globalsecurity.org

Airspace Control and Air Defence

               Close coordination must exist between ASC agencies. The control areas and functions must be clearly spelt out. Data-linked communications enable this process. Timely, tailored, and fused situational awareness is crucial. Also, there is a need for the assessment of adversary capabilities and vulnerabilities. Air defence commander is responsible for early warning, and launching Operational Readiness Platform (ORP) aircraft or diverting friendly airborne AD aircraft to take on the threat. Positive airspace control is required. Close control, broadcast, tactical or data-link control has to be provided to the Defensive Counter Air (DCA) missions and assigns targets to surface-to-air weapons units. Pre-planned air support operations, and air reconnaissance missions also require support. Operators should be able to recognise and act on electronic warfare actions using active and passive measures.

AD Weapon Engagment Zones. Image Source: semanticscholar.org

Technological Support

          ASC is supported by radars, aircraft transponders, flight data processing systems, special software for fully automated systems and conflict alerts and algorithms for a possible vectoring solution. Area penetration warning for preventing restricted area entry. Operational data links (ODL) allow digital messages between platforms and the ground systems. Screen content recording allows better reconstruction and post-event analysis.

Air Space Control in the TBA

          The airspace control order provides the details of coordination measures for the air-tasking cycle and includes fire support coordination measures, air defence areas and air traffic areas along with other airspace information.  Airspace de-confliction at the operational level normally occurs within the air operations centre. De-confliction at the tactical level is handled by ATC and radar controllers. Degraded C2 environment is catered for. The air component commander must ensure that the surface commander’s listed critical assets are protected. Fire support coordination should allow commanders rapid engagement of targets. Air and surface elements must remain to use the same geographically grid.  Joint networks are crucial for integration across components.  Coordination with civil air operations is important during transitions into or out of war zones. Preventing collision between airborne platforms/objects is a task. 

Tactical Battle Area. Image Source: bharatdefencekavach.com

Air Space control – Indian Scenario

          In the TBA, both sides air effort tries to engage the adversary ground forces. IAF will support the Indian army. There will also 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 radars of the other services. Such a picture is made available at the tactical air control (TAC) level to the Army and at the maritime element of the Air Force (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 is coordinated by the Indian Navy. 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 an 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 the battle.  Similarly, air elements operate with the Indian Navy.  

Forward Air Control. Image Source: czdefence.com

          To carry out the above tasks, detailed arrangements are in place at successive levels of command (Corps/Division/Brigade etc.). The apex control of ASC is with the Air Force being the largest user of air space. The instructions for allowing or denying the use of air space to a user are laid out both as standing instructions (height bands, time slots, fly/no-fly zones and more), as well as, in the form of dynamic and instant instructions applicable to a user at a point in time. The IAF is now aligning all the ASC functions through its Integrated Air Command and Control System (IACCS).

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

ASC and Civil Traffic

          The ASC organisation also takes in its fold civil aviation with a detailed institutionalised tie-up between the Air Force and the Directorate of Civil Aviation (DGCA). The Next Generation Air Transport System (NAS) will transform the current airspace and shorten air routes transferring GPS location using data-links. There have been many incidents during Cold War and more recently near conflict zones where airliners have been shot by air defence aircraft and missiles. Any airspace management has to ensure civil aircraft safety. Terrorists in the Air is now a real threat. Terrorists are acquiring weapon-laden UAVs or surface-to-surface missiles.  A terrorist has the advantage of choosing a time and place of attack.  While the response to the threat would be conventional, air defence procedures have to be tailored to tackle possible rouge aircraft at short notice.

Urban Air Mobility. Image Source: Nasa

Space-Based Assets and Applications

          Satellites in Space today support a variety of optical, infra-red (IR) and radar-based sensors for surveillance, mapping, communications, data networking, and navigation. The dependence on space for ground operations has become phenomenal.  Rivals will try to decapitate such systems. The number of satellites is increasing every day.  The day is not far when hypersonic airliners will transit through near space.  The line dividing space and the atmosphere is thinning. This is adding a new dimension to ASC. Weaponisation of space in the form of directed-energy lasers or kamikaze satellites is a possibility. Ground-based AD and ASC uses satellites for their tasks.

Space-Based Assets. Image Source: The Diplomat

Connectivity and Cyber Threat

          All operations are now network-centric, and platforms are electronically talking to one another and sharing critical data.  Situational awareness (SA) is being created through networked sensor inputs.  Each service has its own secure dedicated net.  Also, there are inter-service networks for sharing common domain information.  A major part of the cyberwar will thus be to attack the surveillance and control systems of the adversary, which will have disastrous consequences. Cyberwar doesn’t require huge armies. It can be launched by a single operator with a simple computer.  The time and place of attack can be chosen. For any ground-based air defence network and ASC to succeed, it has to defend its various elements from cyber-attacks.

Connectivity and Cyber Threat. Image Source: Financial Times

Permeation of UAS and Regulatory Issues

          Unmanned systems (UAS) numbers are increasing. They are now taking on all kinds of combat roles, and are a new challenge for ASC. They operate 24×7. Teaming of manned and unmanned vehicles is a reality. Indian armed forces will be inducting UAS in larger numbers. UAS operations have to be factored in any ASC. The problem of regulation of the UAS is another challenge. India’s Directorate General of Civil Aviation (DGCA) released draft regulations (DRs) for civil use of UAS in November 2017. The UAVs have been classified according to their weight, and are expected to be in visual line of sight during the daytime only and operate below 200 ft.  Large commercial drones will be registered by the DGCA as per International Civil Aviation Organisation (ICAO) regulations and allotted a unique identification number (UIN).  There will be an unmanned aircraft operator permit (UAOP).  All the remote pilots must undergo requisite training. Drones will have to be equipped with RFID/SIM with a return to home option and anti-collision lights.  There are restrictions for Drones operations near airports and other sensitive areas to be notified from time to time.

Permeation of UAS Systems. Image Source: uasvision.com

Military Civil Coordination

          Select expressways are being cleared for operations in operations, or emergencies. Networking of civil radars and ATC is already on.  Military aircraft would be accorded direct routing priority.  There will be height band restrictions on civil traffic during operations. There are many dual-use airfields. These have typical operational peculiarities.  Most fighter aircraft require arrestor barriers or rope for hooks.  There are peculiar security issues for military airfields.  Also, many airbases will have fully armed aircraft on operational readiness platforms (ORP) for take-off at short notice. Procedures for the approach and landing of a battle-damaged aircraft are considerably different.  Civil aprons may be used for the dispersal of IAF assets.  ASC has to factor in all these peculiarities. 

Military Civil Coordination. Image Source: Twitter @skeyesBE_EN

Artificial Intelligence in Air Space Management

          Computer systems now perform many tasks that normally required human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages. Artificial Intelligence (AI) has great scope for ASC. Intelligent machine systems can interpret complex data; perceive the environment and take appropriate action using problem-solving techniques. AI will augment human decision-making for ASC, especially during high air movement and will be more predictive to avoid potentially dangerous events. It will help Go-No-Go decisions.  AI will relieve the radar and air traffic controller from the current chronic fatigue. It will greatly support the very dynamic ASC challenges and provide maximum freedom of operations.

Challenges Ahead

          A mix of manned-unmanned operations, including UAS swarms, will be the first major ASC challenge. Intelligent onboard systems will exchange processed information with air traffic and fighter controllers over high-speed digital data links.  On-board collision avoidance and advanced traffic display systems will greatly improve the situational awareness of pilots and controllers. The information-rich environment will require integrity and security of data.  Sifting through raw data to make it meaning full dissemination, display and use, will be required. The human-computer interface will be crucial. Switching to newer technologies will have to be smooth. The air traffic and projectile density in the TBA will continue to increase. The airspace in future will be ‘dynamic’, but ASC will be supported by accurate navigation, height measurement and precision weapons.  

The myriad number of sensors will help create a very realistic day and night all-weather situational picture for the commanders and controllers to manage the airspace more efficiently. It will be possible to display a 3D dynamic picture in an underground bunker using data. AI will support quick decision making. It will increase freedom of operation. The hold-fire orders will get minimised in time and space. De-confliction will be automatic and continuous in real-time. There will be a need for more and more aerial platforms to be new technology compliant and have appropriate avionics and data links. Networks will allow the control centres to be secure and placed at long distances from the fog-of-war. Technology will allow civil and military aircrew greater freedom to choose flight paths and alternative airfields even in real-time. Next Generation initiatives will be more automatic, and flexible enough to accommodate a wide range of users. Cybersecurity will have to be ensured. Procedural back-ups will have to remain in place. Technologies are evolving very quickly. It is imperative for any emerging nation to move with the times.

This article was first written by the author for the Indian Defence Review April-June 2021 Issue

Header Image Source: Nasa

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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