Modernizing the worldwide Air Traffic control system to meet the growing demand for air travel and the aviation industry is an urgent issue. The International Civil Aviation Organisation (ICAO) has introduced the concept of communication, navigation, and surveillance for Air Traffic Management {CNS/ATM} to enable improvements in Air Traffic Management worldwide through the application of modern technologies to new Air Traffic Services {ATS}.

ICAO, in 1983, established a special committee on Future Air Navigation System (FANS) to study the increasing limitations and restrictions being placed` on civil aviation in the areas of Communication, Navigation, surveillance and Air Traffic Control.

The committee has, as its major assignment, the study of present system and the rising applications of satellite technology and concluded that the only viable solution to meeting the future needs of global aviation, and on a cost-effective basis, was the exploitation of satellite technology. This, as recommended by the FANS committee, became known as Communication, Navigation, Surveillance, and Air Traffic Management. The 10th Air Navigation Conference approved this in 1991 and the implementation of which will be through regional planning groups. The concept is based on emerging satellite technology that offers a wide variety of benefits including precise point-to-point navigation, robust, high capacity, digital communication using data transfer technologies, improved surveillance capabilities with Automatic Dependent Surveillance (ADS), and a new concept of managing Air Traffic operations rather than controlling them. The FANS committee was set up with the objective of studying the new concept and technologies, and to make recommendations to overcome 20th century problems and take aviation into the 21st century.

The committee concluded that the limitations of the present system were so restrictive to effective Air Traffic management that the problems could not be overcome except by the new systems. This system is called CNS/ATM.

What Is CNS/ATM

This is an acronym for communication, navigation, surveillance / air traffic management. It is simply an integration of advanced global communication, navigation, and surveillance with a modern efficient Air Traffic Management system that employs advanced digital and satellite technologies that support a seamless air traffic control system. This system is not solitary but requires an advanced capability in the aircraft that works in harmony with air traffic management.

Since the present air navigation system can no longer support the predicted levels of the aviation industry over the next couple of decades, the CNS/ATM was adopted to erase some of the deficiencies of the present system. These deficiencies amongst others include:

1.   Line-of-sight systems in terms of propagation, distance accuracy, and reliability.

2.   Difficulty in implementing and operating systems in a consistent manner worldwide.

3.    Limitations of ground and voice communications.

4.   Lack   of   digital   air-ground   data interchange   system   to   support automation in air and on ground.

As   soon   as   the   concept  was   approved, manufacturers such as Aero data, Sofre'ava, Northrop Grumman, AEA Technology, began developing equipment that could resolve the limitations to these old systems and the result of which are being put into use in many European countries.

CNS/ATM system will improve overall efficiency, capacity and services, reduce operational and maintenance cost, modernize the ATC system inexpensively, creates a seamless airspace, enhance safety, improve infrastructure with minimum investment, and above all, reduce the stress on both the flight crew and ATC thus reducing the incidence of airmiss.

Others benefits from the system include

1.   New, improved and enhanced communications through data link technology, i.e. direct link between pilot and ground facilities without voice.

2.   Surveillance will be available in all areas where radar is not available such as oceans, mountains, jungles, deserts and other remote areas.

3.   Satellite navigation provides point-to-point navigation capability, which permits aircraft to fly direct from point of departure to destination without the needless zigzag commonly associated with VOR navigation-thus reducing fuel consumption and saves time.

4.    Satellite navigation equally provides better access to the airport.

5.   There is usually increase in safety, in productivity and efficiency through automation. However, the full benefit of these modern technologies   depends   greatly   on   a common, accurate situational awareness of flight conditions in the cockpit and in the air traffic control center.

Moreover, the increased use of automation in ATC results in more complex interactions between   flight   crew   and   controller. Therefore,   airborne   and   ground   systems participating   in   these   exchanges   of information   must   be   consistently   and concurrently informed of traffic conditions.

The 1C AO Principles of CNS/ATM

The CNS/ATM system was in accordance with article 44 of the convention and for the implementation of the system to be of benefit to all states; ICAO council, on 9^th of March 1994, under a universally agreed upon set of recommendations, declared that,-

1.   The system must have a universal accessibility and must be available without discrimination.

2.   The system does not infringe on the sovereignty, authority or responsibility of the states to control aircraft and enforce safety.

3.   ICAO maintains the functions and responsibilities of developing rules, recommendations, and procedures to the CNS/ATM system.

4.   The system shall make optimum use of existing organisational structure and operate in accordance with existing institutional arrangements and legal regulation.

5.   The states share the technical knowledge of the concept.

6.   The Global Navigation Satellite System (GNSS) be considered as a world navigation system, accepted by all member states.

7.   Airspace be organized and utilized to the fullest extent consistent with CNS/ATM system, that the system shall be implemented to overcome present day limitations.

8.   CNS/ATM systems will be consistent, and that the quality of the system service shall comply with ICAO standards, and that the system will be continuously available to include effective arrangements to minimize unavoidable system malfunction.

9.   States have the right and authority to recoup implementation costs through a reasonable cost allocation program between all users, in accordance with laid down procedures.

Implementation of CNS/ATM

Certain steps that are necessary to conduct any implementation of the custom system should be followed. These steps - amongst several others, should be satisfied in order to ensure a smooth and beneficial transition to the future system. Such steps include: 1. Internal Assessment and Project Development.

This   provides   the   baseline   for   the transition programme and will identify weakness, strength and capabilities of the operators. The assessment will serve as a basis for developing a systems requirement document.

2.   Requirements definition and cost benefit analysis.

Defining requirements is the most important step in this concept's transition. All requirements should be defined and the cost benefit analysis be completed before any large procurement takes place. The requirement document could be developed, using the data derived from the internal assessment.

3.   Transition   Planning   and   Specification Development

The transition plan can be developed after you have decided on what you need. Incremental development is suggested in the transition program and the CNS/ATM should be designed to be implemented in a conservative way based on how much you can afford or how capable you are.

4.   Financial Requirements, Funding, Cost Recovery.

This is a very important issue in the implementation of CNS/ATM system as a basic and common problem in contracting states. Fund could be arranged to finance the implementation of the system transition. This could be through loans of which a feasibility study and a requirement document with associated cost benefit analysis are generally required. The requirement of the loan will not pose much problems, if the project can be manned effectively, since air carriers will pay for any service that saves them time - which is money, thus, large part of the expended funds for CNS/ATM can be recovered or recouped through the user fee program.

5.   System   Requirements,   Procurement, Installation

This is another important area that should be considered carefully. System  requirement ' needs   to   be   reviewed   to   ensure   the recommended   improvements   meet   the system   requirements,   by   ensuring   that considerations,  such as power,  structures, siting,   access,   etc   meets   the   system requirements.

Procurement should be made from an authorized vendor who is experienced in the development and manufacturing of the equipment being considered. Companies such as Aero data and AEA technology are involved in the manufacturing and installation of these equipment.

6. Training and Human Resources CNS/ATM training  is yet to receive the importance or priority it deserves in many third   world    countries   -   thus    the implementation is proceeding slowly.

The CNS/ATM training is a necessity and the lack of which could easily cause a barrier to the transition. Most decision makers and ATC administrators are still unsure or not well educated about the CNS/ATM system, thus, they have difficulty interpreting and making educated decisions for the effective implementation and transition.

CNS/ATM training could be obtained through; seminars, conferences, books, brochures, and digests, but the most promising method is an academic setting whereby you are face-to-face with a knowledgeable and qualified instructor. The training and qualification of controllers and other individuals who will work in CNS/ATM is of a concern. CNS/ATM will require more controllers, yet many countries have no plans for such. Some countries take too long to train and certify their control personnel, which could result in hardship on ATC operators.