Africa’s ATC challenge

On 18 February 2011, a multilateral partnership known as the Indian Ocean Strategic Partnership to Reduce Emissions (INSPIRE) was formed in Dubai. The INSPIRE partnership is intended to be collaborative network of partners and peer organisations across the Arabian Sea and Indian Ocean region dedicated to improving the efficiency and sustainability of aviation.

INSPIRE is aimed at supporting operations in three distinct regions:

• Southern Africa – Australia / South East Asia
• Arabian Gulf – Australia
• South-West Indian Ocean – Arabian Gulf.

In consultation with stakeholders, the INSPIRE partners have compiled a series of recommended procedures, practices and services that have been demonstrated or have shown the potential to provide efficiencies in fuel and emissions reduction management. They encompass all phases of flight from ‘gate-to-gate’ and are designed to reflect the requirements, in particular but not limited to, long haul flights that typically exceed eight hours in duration. The recommendations contained below are for procedures, practices and services that are fully developed or that have reached a state of demonstrable maturity:

• Surface Movement Optimisation
• Departure Optimisation
• Oceanic Flight
• User Preferred Routes
• Dynamic Airborne Reroute Procedures
• Flexible Track Systems
• Oceanic Separation Minima
• Reduced Vertical Separation Minima
• Cruise Climb (Block levels)
• Time Based Arrivals Management
• Optimum Profile Descents.

Air Traffic and Navigation Services (ATNS) as part of the INSPIRE programme provide significant savings in fuel and emissions. A recent SAA flight from Perth to Johannesburg achieved fuel savings of 453kg and roughly 1260kg of CO2 emissions.

Following the success of this demonstration flight, the formation of an INSPIRE daily programme was introduced by ATNS (Johannesburg Operations) and Airservices Australia.

The sixth INSPIRE demonstration flight between Dubai and Durban took place on 4 December 2011. This was the first flight over the African continent for the INSPIRE programme.

The flight operated on time and received expeditious taxi in Dubai, no slots into Muscat FIR and continuous climb through the Muscat FIR. Direct routings in Muscat and en-route to Durban ensured Flight UAE775 arrived in Durban 23 minutes early, even though the runways in use (30R Dubai and 06 Durban due wind) were not the preferential runways for short track miles. The estimate savings in emissions during this flight is 5,700kgs CO2 or 1.809 tonne saving in fuel.

Flexible Use of Airspace (FUA)

South Africa is renowned for its efforts in FUA. The continental airspace will continue to be managed under the concept of FUA allowing access by all users via Collaborative Decision Making (CDM), supporting both aerodrome and airspace system capacity. This initiative has been in place since before 2000 and the evolution thereof will continue throughout the short-, medium- and long-term.

ATM roadmap

The primary driver for the ATNS ATM roadmap is to achieve an interoperable, global air traffic management system for all users during all phases of flight that meets agreed levels of safety, provides for optimum economic operations, is environmentally sustainable and meets national security requirements.

The objective of the roadmap is to guide the future ATNS ATM System and establish the framework of operational improvements and their deployment interdependencies adapted to the ATNS area of responsibility in response to the strategic plan. The roadmap serves as the initial starting point for the planning and submission of the tri-annual ATNS permission request to the regulating committee. The implementation and research plans will be developed on a timely basis and by the applicable departments within ATNS to support the roadmap. The roadmap, aligned to the ICAO ATM operational concept, defines seven interdependent concept components. These components, as follows, are integrated to form the future ATNS ATM System.

Airspace organisation and management

Airspace organisation establishes airspace structures in order to accommodate the different types of air activity, traffic volumes and differing levels of service. Airspace management is the process by which the airspace options are selected and applied to meet the needs of the ATM community.

Airspace management remains dynamic and flexible. Due to the relatively small volume of the South African continental airspace and the short routes, the city pairs in South Africa are serviced by a fixed route structure supporting RNAV operations. Flex tracks will be employed in the pre-tactical and tactical phases of operation to support efficiency and predictability during unusual operations such as weather avoidance. Random routing is applied within the Oceanic en-route operations and has been implemented since 1997 in the IORRA together with an accommodation for vertical and lateral random operations. Within the AORRA lateral random routing operations were established in 2006 and will be further optimised to support vertical and lateral random operations. The continued systematic deployment of RNAV applications will minimise congestion and improve the capacity and efficiency of the ATM system in en-route and terminal airspace. Performance based navigation will be implemented in accordance with the south African PBN Roadmap ultimately achieving 4-D Trajectory Management. Specific initiatives supporting this roadmap component are ATFM, the development of a navigation specification to support PBN and a review of the South African airspace to enable performance based operations.

Aerodrome operations

As an integral part of the ATM system, the aerodrome must provide the agreed to ground infrastructure including, inter alia, lighting, taxiways, runway and runway exits, precise surface guidance to improve safety and to maximise aerodrome capacity in all weather conditions. ATNS does not own or manage the aerodromes in South Africa. ATNS will continue to contribute to the successful and safe operations of aerodromes and optimised capacity and throughput. In order to comprehensively consider the role of aerodrome operations within the ATM system, ATNS considers the aerodrome, associated airspace and operating procedures as integral to the ATM system solution and in support of 4-D trajectory management. CDM is used at the strategic, pre-tactical and tactical levels to achieve optimised operational throughput. The ATM Roadmap initiatives related to aerodrome operations are focused on improved information exchange and situtraional awareness supported by automation aids. ATNS is developing specific plans and actions to reduce runway occupancy and prevent runway incursions.

Demand and capacity balancing

Demand and capacity balancing strategically evaluates system-wide traffic flows and aerodrome capacities to allow the airspace users to determine when, where and how they operate, while mitigating conflicting needs for airspace and aerodrome capacity. This collaborative process allows for the efficient management of the air traffic flow through the use of information on system-wide air traffic flow, weather and assets. Through collaborative decision-making at the strategic stage, assets will be optimised to maximise throughput, thus providing a basis for predictable resource allocation and traffic scheduling.

Through CDM, when possible, at the pretactical stage, adjustments will be made to assets, resource allocations, projected trajectories, airspace organisation, and allocation of entry/exit times for aerodromes and airspace volumes to mitigate any imbalance. Airspace concepts and design must take cognisance of airspace user equipage. Any new airspace concept designs will ensure that the major users of any airspace or airspace system is not prevented from benefiting from new technologies, both airborne and terrestrial for the sake of accommodating less modern users. Performance based navigation will be implemented in accordance with the south African PBN Roadmap ultimately achieving 4-D Trajectory Management.

At the tactical stage, actions will include dynamic adjustments to the organisation of airspace to balance capacity; dynamic changes to the entry/exit times for aerodromes and airspace volumes; and adjustments to the schedule by the users, supporting 4-D trajectory management.

Demand and capacity balancing actions aimed at ensuring safety, equity and access is a CDM process in which the collection, collation and analysis of data to produce an accurate picture of the demands and constraints that will affect any particular airspace volume will begin long before the day of operations. ATNS supports the overall DCB activity through annual traffic forecasts developed by means of a compre – hensive forecasting model which informs the capacity initiatives of the company. Traffic forecasts, declared system and airspace capacities, ATC workload and complexity of operations are used to determine the need for additional sectors. The information gathered from these activities informs the ATNS human capital plan, the capital expenditure plan and ultimately the ATNS permission submission.

Traffic synchronisation

Traffic synchronisation refers to the tactical establishment and maintenance of a safe, orderly and efficient flow of air traffic. It encompasses both the ground and airborne part of ATM and constitutes a flexible mechanism for capacity management by allowing reductions in traffic density and adjustments to capacity in response to variations in demand.

There will be a progression to dynamic 4-D trajectory management and negotiated conflictfree trajectories. Airspace concepts and design will take cognisance of the advances in user equipage thereby ensuring that ATNS and users of the airspace or airspace system will benefit fully from new technologies, (both airborne and terrestrial). Optimisation of traffic sequencing will achieve maximisation of runway throughput for all existing runway configuration. 4-D trajectory management will be progressively introduced to minimise congestion and to improve over-all system throughput e.g., the use of taxi sequencing equipment (both to and from the gate).

ATNS is pursuing regulatory amendments to support the use of station keeping requirements placed on flight crews in all phases, to maintain the required sequence and traffic flow. This will ultimately support the concepts of self separation and free flight. Flight parameters will be available to the ATM system, allowing for dynamic spacing and sequencing of arriving and departing aircraft, taking cognisance of wake vortex, which will continue to be a determinant of minimum spacing. Specific initiatives which support traffic synchronisation are PBN implementation, advanced arrival and continuous descent approaches and dynamic 4-D Trajectory management.

Conflict management

Conflict management will incorporate all relevant required technologies as described in the ICAO Global ATM Operational Concept document (ICAO Doc 9854).

Conflict management consists of three layers: strategic conflict management through airspace organisation and management, demand and capacity balancing, and traffic synchronisation; separation provision; and collision avoidance.

Conflict management limits, to an acceptable level, the risk of collision between aircraft and hazards. Hazards that an aircraft will be separated from are: other aircraft, terrain, weather, wake turbulence, incompatible airspace activity and, when the aircraft is on the ground, surface vehicles and other obstructions on the apron and manoeuvring area. Key initiatives by ATNS include reduced separation minima in terminal and en-route airspace, self separation and the strategic de-confliction of traffic.

Airspace user operations

Airspace user operations refer to the ATM-related aspect of flight operations. The ATM system accommodates diverse types of airspace user missions. The system will need to evolve to accommodate increasingly diverse types of vehicles and performance capabilities. These are expected to encompass, but are not limited to, air transport, military missions, business, aerial work and recreation. These missions will have differences in planning horizons, from those scheduled well in advance to just prior to flight. Both manned and unmanned aerial vehicles will form part of the ATM system.

The ATM system will accommodate the limited ability of some vehicles to dynamically change trajectory. The development of the ATM system and aircraft capabilities, based on global standards, will ensure global interoperability of ATM systems and airspace user operations. User requirements and operational capabilities (crew and equipment) will be addressed in order to enhance safety and efficiency through CDM, in accordance with the South African National Airspace Master Plan. PBN implementation will allow dynamically-optimised 4-D trajectory planning. ATNS plans to continuously meet the expectations of the airspace users regarding predictability, harmonisation and interoperability. The dynamic flight and flow data available from FF-ICE will be incorporated within the ATM system to enhance the general, tactical and strategic situational awareness and conflict management of the airspace users and ATNS. Airspace User Operations are supported through the CDM process.

ATM Service Delivery Management

ATM Service Delivery Management (SDM) will operate in a more dynamic way instead of today’s more static operations with codified procedures. The migration will be from current controlling of individual aircraft trajectories to seamlessly managing flight trajectories from gate-to-gate for all phases of flight and across all service providers through CDM.

The SDM will more efficiently address the balance and consolidation of the decisions of the various ATM components and their related processes and services, as well as the time horizon at which, and the conditions under which, these decisions are made. SDM is composed of three main functions which will be executed in a collaborative manner:

• ATM Performance management
• ATM Services management
• ATM Assets management.

SDM will manage the optimised performance of the ATM system through the management, planning and co-ordination of the provision of ATM services. ATM system design will be determined by collaborative decision making based on system-wide information sharing and system-wide performance cases. ATM service delivery management principles include:

• Trajectory, profile, and aircraft or flight intent (predictability)
• Management by trajectory
• Clearance
• Aircraft performance characteristics.

AIS to AIM Roadmap

The Global Air Navigation Plan (Doc 9750) was developed as a strategic document to guide the implementation of CNS/ATM systems with respect to the Global Air Traffic Management Operational Concept (Doc 9854) and the Strategic Objectives of ICAO.

The AIS to AIM roadmap has been developed to expand upon the direction given in Doc 9750 for the future development of aeronautical information. The changes foreseen are such that this development is being referred to as the transition from aeronautical information services (AIS) to aeronautical information manage ment (AIM). This roadmap offers practical guidance and advice to regional planning groups and States for development of the imple mentation and funding strategies that will be required for the global plan initiatives related to aeronautical information. It identifies the major milestones recommended for a uniform evolution across all regions of the world, specific steps that need to be achieved and timelines for implementation.

The expectations are that the transition to AIM will not require many changes in terms of the scope of aeronautical information to be distributed. The major change will be the introduction of new products and services and an increased emphasis on better data distribution in terms of quality and timeliness in order to meet user requirements and contribute to improved safety, increased efficiency and greater costeffectiveness of the air navigation system.

Safety roadmap

The endorsed safety roadmap supports the strategies and commitment to participate in the collaborative processes necessary to realise the strategic imperatives of ATNS. Given the dynamic nature of the Safety environment the Roadmap will require revision from time to time to reflect the changing situation and to include the contributions of all ATM stakeholders. Optimal performance in safety, as in many other endeavours, is achieved through the systematic application of effective management practices. A good system for managing safety is comprised of elements similar to those in other management behaviours. It includes effective goal-setting, forecasting and planning, the gathering of accurate information, effective and ongoing needs determination, comprehensive analysis, regular evaluation and feedback, and effective corrective actions. These practices are designed to lead to continuous improvement in the products and services delivered by ATNS.

CAD implementation

ATNS has embarked on the implementation of a single repository of all aeronautical data. The Centralised Aeronautical Database (CAD) establishes and maintains a database where digital aeronautical data from are integrated and used to produce current and future AIM products and services. This is the primary step in support of the transition from AIS to AIM. It is envisaged that the CAD can also serve as regional solution for other States.

About the author

Hennie Marais started his career in aviation in 1980 and obtained Aerodrome, Approach and Area Procedural and Radar validations. He has worked as an Aerodrome, Approach and Area Procedural and Radar controller at various airports and Air Traffic Control centres within South Africa and also served as an on-job-traininginstructor and validation examiner. He has served as the Head of ATS Training and Manager Compliance and Standards at the Aviation Training Academy.

In September 2004 he was transferred to the Air Traffic and Navigation Services corporate offices in Isando as Manager of Standards Assurance. In this post he was responsible for the safety and regulatory oversight function within the company. He was appointed as Senior Manager ATM Planning, Research and Development at the ATNS Department in Isando from July 2006, and was responsible for the strategic planning of the ATM services to be delivered by ATNS in the future.

Mr. Marais is a member of the ICAO ATM Requirements and Performance Panel.