Modernisation of Air Traffic Management Operations -Safer and Expeditious

Aviation industry in India has gone through turbulence with some of the carriers closing down and some of the existing airlines running under losses .To sustain in the highly competitive environment, specially for the low cost carriers, many airlines have implemented several cost cutting measures like purchasing only one type of aircraft to minimise maintenance costs, operating only economic class flights with reduced fares to accommodate as much passengers as possible. All these have lead to attract huge number of passengers and enormous increase of air traffic across Indian airspace.

image:freefigitalphotos.net, num_skyman

Nevertheless, this increase in air traffic cannot be sustainable alone without proper infrastructure, airport operations and air traffic control services. All these collectively play a major role in enhancing the growth of aviation industry by making flight operations safer and timelier. Though among the carriers, both private and government players exist, the infrastructure and the airport operations are mainly controlled by the Airports Authority of India, the public body. In recent times, some airport terminals are getting privatised and public private partnership is created for development of those but the air traffic management is solely owned by Airports Authority of India.

With the rise in number of flights, A.A.I  has come up with several measures for modernisation of air traffic management operations to ensure better utilisation of airspace ,safety , orderliness and expedition of the air traffic movements -

• A-SMGCS (Advanced-Surface Movement Guidance and Control System) -During winter due heavy fog aerodrome visibility becomes low. It has been very difficult for the Controllers to plan and guide the movements during early morning peak traffic hours when visibility is as low as 50 metres only. A-SMGCS includes a display monitor which provides the exact position of aircraft to assist the controllers. For the operation of A-SMGCS, MLAT (Multi Lateration ) antennas act as secondary RADAR-s and SMR –s (Surface Movement Radar) act as primary RADAR-s .An aircraft is supposed to turn on its transponder while it is taxiing so that all its necessary details are displayed in the form of video in the A-SMGCS display. And primary RADAR takes care of any object in the aerodrome which has no transponder attached to it, but which may turn out to be an obstacle for the moving aircraft . A-SMGCS aids the Air Traffic Controller during time of   busy traffic or low visibility and has reduced the workload for Surface Movement Control. Different levels of A-SMGCS exist. For level-1 system (as present in Kolkata), either visual contact or position report from the pilot is required to complement the A-SMGCS.

• PBN (performance based navigation), SID(standard instrument departure) and STAR(standard instrument arrival) - Previously the arriving and departing aircraft were given conventional SID s where aircraft had to move to and from the VOR (VHF Omnidirectional Range) or NDB(Non Directional Beacon) in particular direction . PBN is based on RNAV (area navigation), a system which provides random navigation , that means the aircraft can be routed on shortest possible course .Implementation of  PBN  provides better utilisation of the airspace , reduction in distances resulting in fuel savings and reduces needs to maintain sensor-specific routes and procedures, and their associated costs .But  the limitations of this system are – ( 1) it cannot be used by those aircraft which are not RNAV compliant  (2) when ATC RADAR display is under maintenance ( 3) when reciprocal runways are used for arrival and departure.

• Upper Airspace Harmonization- With the growth of air traffic, it is becoming more challenging to utilise the airspace more efficiently to increase safety and expedition of the flights simultaneously. So upper airspace harmonization is getting implemented across India.

At present the Indian airspace is divided into 5 FIR-s namely- Chennai, Delhi, Guwahati, Kolkata and Mumbai FIR-S and

11  CC-s(Area Control Centres) namely –

• Chennai ,Hyderabad ,Mangalore ,Trivandrum  ACC-s within Chennai FIR
• Delhi and Varanasi ACC-s within Delhi FIR
• Guwahati ACC within Guwahati FIR
• Kolkata ACC within Kolkata FIR
• Ahmedabad, Mumbai and Nagpur ACC-s under Mumbai FIR

With the concept of upper airspace harmonisation for each FIR, the upper airspace above a specified flight level will be under the control of 1 Upper ACC. This results into the amalgamation of all ACC-s under each FIR into 1ACC and formation of 4Upper ACC-s - Chennai, Delhi, Kolkata and Mumbai in total (Kolkata will take charge of the upper Guwahati FIR airspace).Each of this 4 Upper ACC-s will have multiple sectors.

All other present ACC-s like Varanasi, Ahmedabad etc will be re-designated as Lower ACC with redesigned vertical and lateral jurisdictions.

Later, the 4 Upper ACC-s will be merged to form 2 Upper ACC-s in total. On such successful integration, the Indian airspace will be designated as Class A which means the following-

• All operations will be following either IFR(Instrument flight rules) or SVFR(Special Visual Flight rules)
• All flights are subjected to Air Traffic Control clearance
• All flights are separated from each other by ATC

This means that there would be better control and co-ordination across the entire airspace.

The upper airspace harmonization has already taken shape in Chennai FIR. In the pilot project of Chennai FIR, Chennai will act as the upper ACC with 5 dynamic sectors and integration of 10 RADARs including a defence RADAR has already taken place. Hyderabad, Mangalore and Trivandrum will be now onwards acting as Lower ACC .

The upper airspace harmonization  requires the following two implementations which are already taking place-

1.   Increased RADAR coverage- Previously some of the crossing points of flight paths were not covered under RADAR scope. This necessitated longer time separation between aircraft crossing at those particular points. Now installation of additional RADAR-s will provide surveillance of the entire airspace by VOR (VHF Omni-directional Range),ADS (Automatic Dependent Surveillance),MLAT (Multi-Lateration ) RADAR-s and smoothen the air-ground communication. This will reduce the time separation between aircraft at crossing points and thus can accommodate more aircraft in a particular path.

Cross Coupling of VHF would lead to multiple sectorization of the airspace thus facilitating the upper airspace integration .

AIDC (ATS Inter-facility Data Communication) will act as ground-ground communication system and will simplify the entire ATS co-ordination system.

The integration of several RADAR-s under each Upper Airspace ACC is possible by the implementation of ATS automation system discussed in the next paragraph.

2.   Air Traffic Services Automation System-The surveillance data from the RADAR-s will be networked with the Flight Data Processing System (FDPS) and will be electronically processed with relevant flight data  to produce an integrated track data on RADAR display monitor. This electronic FDPS along with other automated tools like  Airspace situation awareness track displays, Automatic co-ordination and Hand-off, Controller Decision Support Tools, Flow management tools, Conflict detection and Safety alert tools, Route conformance warning tools etc forms the integrated ATS automation system. This will aid the Air Traffic Controllers to handle the traffic more effectively with enhanced safety , reduced flight time and better airspace utilization.

Implementation of ATS automation system is completed in some ACC-s like Chennai, Mumbai, Delhi etc and it is about to be completed in some like Kolkata ACC. It is estimated that by mid 2014 all the existing ACC-s of India will start operations under the implemented Automation System.

The several benefits of the modernisation methods implemented in Air Traffic Management Operations are-

• Increase in the aircraft handling capacity of the runways
• Better utilization of the entire airspace
• Easy and effective air-air and air-ground communication
• Efficient co-ordination between adjacent Air Traffic Control Centres
• Making flight movements more safe and orderly
• Decrease in total flight time due effective separation procedures
• Reduction in fuel consumption
• Reduction in operation costs
• Cutting down carbon emission and maintaining environmental safety

The future of Civil Aviation in India is escalating upwards at a fast pace due to these rapid advancements in the Air Traffic Management Operations.

The article has bee authored by Dipanwita Ghosh, XLRI, Jamshedpur

References-

1)I have worked as an Air Traffic Controller with Airports Authority of India for 3 years. I have witnessed the above mentioned developments myself.

2)www.aai.aero