For discussion
on 7 May 1999


Civil Aviation Department
New Subhead "Study and Trial of Satellite-based Communications, Navigation, Surveillance/Air Traffic Management Systems"

    Members are invited to approve the creation of a new commitment of $233,800,000 in money-of-the-day prices for the study and trial of the satellite-based Communications, Navigation, Surveillance/Air Traffic Management Systems for air traffic control operation.


We need to start the study and trial of the satellite-based Communications, Navigation, Surveillance/Air Traffic Management (CNS/ATM) Systems for Air Traffic Control (ATC) operation to be followed by subsequent implementation to modernise our ATC facilities and comply with the Global Implementation Plan of the International Civil Aviation Organisation (ICAO). The project is important for enhancing flight safety and efficiency as well as maintaining Hong Kong's status as a centre of international and regional aviation.


2. The Director of Civil Aviation, with the support of the Secretary for Economic Services, proposes to create a new commitment of $233,800,000 for the study and trial of the satellite-based CNS/ATM Systems.


Development of CNS/ATM Systems

3. The existing ATC systems rely mainly on ground-based radar and communications equipment. In the early 1980s, it became evident to ICAO that the present ground-based ATC systems would not be adequate to meet the needs of the 21st century. They would not be able to cater for the ever increasing air traffic or maintain a high standard of safety as airspace around the world gets more congested. Moreover, they could not deliver the operational benefits that could be achieved by using modern technologies such as aircraft fuel saving, reduced flight time and better on-time performance. In light of this, a Special Committee on Future Air Navigation Systems (FANS) was established by ICAO in 1983 to study, identify and assess new technologies as well as to make recommendations for the future development of navigation systems for civil aviation.

4. The FANS Committee examined in great detail the various technologies available with a view to recommending a set of new standards which would best meet the future needs of the aviation industry. The systems developed by the FANS Committee are known as the satellite-based CNS/ATM systems. With the endorsement by ICAO in 1993, they provide internationally accepted standards for the modernisation of ATC systems around the world. These new systems include the following major elements -

  1. Communications

    This mainly involves the introduction of satellite data and voice communications. Such satellite-based communications are capable of global coverage as compared to the limited effective range of the present ground-based systems. In addition, they allow regular use of data communications, as opposed to voice communications (which is more susceptible to interference or interruption) under the existing systems. As a result, they offer new opportunities for improvements in air traffic management, particularly real-time sharing of aeronautical information among ATC centres of different aeronautical authorities, aircraft in flight and airlines operation centres.

  2. Navigation

    This involves the use of another set of satellite signals from the Global Navigation Satellite System for navigation, as opposed to ground-based beacons and navigational aids under the existing systems. The new systems provide high-integrity, high-accuracy and all-weather world-wide navigation services.

  3. Surveillance

    This involves the use of multiple facilities to improve surveillance of aircraft. A Mode S radar facility which provides the capability for individual addressing and thereby facilitates aircraft identification and supplements the traditional Secondary Surveillance Radar in high-density traffic airspace. An Automatic Dependent Surveillance (ADS) which automatically and continuously transmits an aircraft's position and other data such as heading and speed via satellite or other communication links to an ATC centre. The real-time information permits an ATC centre to control air traffic more effectively, particularly in areas where it is not cost-effective to provide radar coverage. An Enhanced Ground Movement Control System which allows more effective surveillance of moving targets such as aircraft, vehicles and ships on, or adjacent to, the airfield including the taxiway, apron, runway and adjacent sea area.

  4. Air Traffic Management

    It includes a number of functions for directing and regulating air traffic, providing aircraft with the necessary flight information and ensuring adequate separation between aircraft. An Integrated Global ATM system which exploits the potential of new technologies through international harmonisation of standards and procedures to enable aircraft and all ATC centres around the world to exchange information in a standardised and efficient manner. Ultimately, this enables aircraft operators to dynamically adjust the preferred trajectories in an optimum and most cost-efficient manner and conduct their flights accordingly.

Benefits of the satellite-based CNS/ATM Systems

5. The use of satellite-based CNS/ATM Systems provides many benefits. The transfer of information using data links instead of voice communication helps enhance the operational efficiency of air traffic controllers and pilots. More frequent and reliable transfer of updated information, such as information on weather at airports and along the flight routes and that on the status of navigational or airport facilities, between aircraft and the ATC centres significantly enhances flight safety and efficiency. Enhanced safety is achieved with the availability of global satellite coverage, which enables accurate surveillance and positive navigational control of aircraft in areas currently not covered by radar or other ground-based navigational aids.

6. The effectiveness of the above functions is further exploited with the installation of the advanced Integrated Global ATM System. This System makes use of the data obtained through the various CNS/ATM components to dynamically manage aircraft in flight. It offers in-flight aircraft a means to adapt quickly to the changing traffic environment or weather condition so that it can choose the optimal and most efficient flight profile. It also provides improved capability for early detection of potential conflict between projected flight paths of different aircraft. When such potential conflict is detected, the System automatically works out proposed action to be taken to resolve the conflict and suggest to the air traffic controllers the appropriate direction to be given to the aircraft concerned. Such capability significantly increases the capacity of busy airspace such as the Pearl River Delta area and enhances flight safety.

7. In addition, with global migration to the satellite-based CNS/ATM Systems, a level of standardisation will exist among various ATC centres, which will facilitate interconnections between ATC systems and support a seamless transition of aircraft from the control of one ATC centre to another. This will result in improved safety and efficiency in ATC as aircraft transcend different parts of the world.

8. In brief, the direct and indirect benefits of the satellite-based CNS/ATM Systems include enhancement of flight safety, increase in airspace capacity, savings in flight time and fuel, as well as reduced disruption to air services arising from adverse weather. The benefits are significant and will be enjoyed by the travelling public, airport operators, airlines and ATC authorities. It was estimated by ICAO in the early 1990s that, from a global CNS/ATM systems implementation viewpoint, the benefits for the whole aviation industry arising from efficiency improvements in the routing and handling of aircraft would be in the order of US$5.5 billion per year. It would be difficult to quantify the benefits that would accrue to the aviation business in Hong Kong. However, on fuel savings alone the benefit is estimated to be some $280,000,000 per annum, assuming that each of the 460 flights operating at Hong Kong International Airport per day could reduce its flight time by ten minutes.

Implementation of the satellite-based CNS/ATM Systems

9. The first Global Implementation Plan for the satellite-based CNS/ATM Systems was worked out by ICAO in 1993 and has subsequently been updated. All Contracting States, including China, are required to comply with the Plan. At the same time, the Asia Pacific Economic Co-operation (APEC) has also established a Satellite Navigation and Communications Systems Advisory Committee to monitor and co-ordinate, in conjunction with the ICAO Regional Office and various APEC economies, the implementation of such systems within APEC.

10. Many countries have commenced the study, operational trial and evaluation of the CNS/ATM elements with a view to complying with the Global Implementation Plan and launching the services of the new CNS/ATM Systems for use by airlines at an early date. In this regard, USA, Japan, Singapore and Mainland China have started the design and trial of at least five key elements of the CNS/ATM Systems.

11. It is incumbent upon Hong Kong as a member of the international aviation community to implement the CNS/ATM Systems to ensure that our ATC systems are compatible with the new equipment being introduced in aircraft and other ATC centres. The Civil Aviation Department (CAD) commenced preliminary planning and investigation on the satellite-based CNS/ATM Systems for Hong Kong in 1992. Initial trial on two elements of the systems, i.e. ADS and the Controller-Pilot Data Link Communication, has started since June 1994. The results have been satisfactory. The trial of these systems will continue with further upgrade in 2000-03 before actual implementation for full operational use.

12. The study and trial to be commissioned by CAD do not aim at verifying the feasibility or cost-benefit of the CNS/ATM concept, which have been well considered, evaluated and finally adopted by ICAO. The main purpose is to evaluate and analyse the characteristics, functionality and capabilities of different but inter-related CNS/ATM elements as applicable to the unique operating environment of Hong Kong. Particular attention will be paid to our dense air traffic, hilly terrain, vast airspace over waters, etc. CAD will then consider, evaluate and prepare a master plan on how Hong Kong should evolve and transit to the new satellite-based systems. The trials will allow us to gain experience on the new CNS/ATM elements, to optimise the application of the new systems for Hong Kong, to draft the operational procedures, and finally to clearly define the technical requirements and most suitable implementation option.

13. Specifically, CAD proposes to take forward the CNS/ATM implementation plan according to the following timetable -

  1. Study Phase - Systems Study and Analysis (1999-2004)

    To carry out a full CNS/ATM Systems study and analysis of various CNS/ATM elements so as to define a master plan for Hong Kong on the evolution of and transition to the new satellite-based systems, including the formulation of time schedule for the trials and implementation of CNS/ATM elements in Hong Kong.

  2. Trial Phase - CNS/ATM Trial and Evaluation (2000-2007)

    To procure and set up mini-scale equipment so as to conduct comprehensive trials and evaluations of various CNS/ATM elements to assess and establish the operational and engineering requirements, system configuration and suitable implementation programmes.

  3. Implementation Phase - CNS/ATM Implementation and Transition (2003-2016)

    To procure operational CNS/ATM Systems including equipment tendering and selection, testing and commissioning and parallel operations of the existing ground-based and the future satellite-based systems, as well as the final transition to, and overall system integration for, CNS/ATM operations.

The CNS/ATM Systems consist of a large number of elements. For each individual one, different timing will be required for its development, trial, evaluation and implementation. This accounts for the overlapping of the three different phases.


Non-recurrent Cost

14. The total non-recurrent project and contract staff costs for the study, trial and implementation of the whole CNS/ATM project are estimated to be $1.04 billion in 1998-99 prices or $1.32 billion in money-of-the-day (MOD) prices, to be expended between 1999-2000 and 2016-17. This cost estimate is worked out based on preliminary quotations from potential overseas suppliers adjusted to take into account local requirements. Since the project involves significant investment and would take 18 years to complete, we propose to seek funds initially for the study and trial phases only. We shall seek Members' approval for funding for the actual implementation of individual CNS/ATM elements when their technical requirements are more clearly defined.

15. The estimated total non-recurrent cost for the study and trial phases of the project is $326.3 million in 1998-99 prices, or $377.2 million in MOD prices, broken down as follows -

1998-99 prices
$ million
MOD prices
$ million
(a) Project costs (see Enclosure 1) 173.7 197.9
(b) Contract staff cost 30.2 35.9
Sub-total 203.9 233.8
Other non-recurrent cost
(c) In-house staff cost(including staff on-cost) 54.9 64.6
(d) Other expenses
  1. system maintenance and spare parts
62.0 72.4
  1. light and power
5.5 6.4
Sub-total 122.4 143.4
Total 326.3 377.2

We are seeking approval of a commitment of $233,800,000 in MOD prices for items under cost items (a) and (b) above.

16. The cashflow for the commitment (the cost for paragraph 15(a) and 15(b)) is estimated as follows -

1998-99 prices
$ million
MOD prices
$ million
1999-2000 2.0 2.0
2000-01 13.8 14.5
2001-02 29.3 31.6
2002-03 29.3 32.4
2003-04 39.3 44.6
2004-05 39.6 46.1
2005-06 18.5 22.3
2006-07 18.6 23.0
2007-08 13.5 17.3

_______ _______
Total 203.9 233.8

_______ _______

For the purpose of bringing up the 1998-99 prices to MOD prices level, the following adjustment factors, as advised by Government Economist, are used -

    Project costs : +2.5% per annum
    Staff costs : 0% for 1999-2000, thereafter +4.0% per annum

17. As regards project costs in paragraph 15(a), please refer to Enclosure 1 for detailed cost breakdown and description.

18. As regards paragraph 15(b), the cost covers the contract staff cost for the nine years from 1999-2000 to 2007-08 to support the in-house staff in the day-to-day monitoring of the study and trials of the CNS/ATM Systems.

19. As regards paragraph 15(c), the cost covers in-house staff costs for the nine years from 1999-2000 to 2007-08 for the posts of one Chief Electronics Engineer, two Senior Electronics Engineers and one Personal Secretary II which form a core team to formulate the implementation plan, specify the equipment requirement, and set out testing and evaluation criteria during the study and trial phases. We have included sufficient resources in the 1999-2000 Estimates of CAD for this purpose.

20. As regards paragraph 15(d)(i), the cost covers systems maintenance and spare parts for the systems used for study and trials between 2000-01 and 2007-08. CAD has to procure the necessary spare parts, rent local and international line circuits, and arrange short term equipment support/maintenance service with the manufacturers. The annual expenditure is estimated to be $4 million initially and will increase to $10 million in 2003-04 when fuller evaluation on more CNS/ATM trial systems commences. Based on CAD's past experience, the annual system maintenance costs are estimated to be about 6% of the project costs.

21. As regards paragraph 15(d)(ii), the cost covers electricity costs for the operation of the trial systems of the same equipment category to be run in parallel for evaluation between 2000-01 and 2007-08. The light and power requirements are estimated to be $0.5 million per year initially and to increase to $0.8 million per year between 2003-04 and 2007-08.

22. Subject to Members' approval of this item, we will include the provision for the purpose of paragraph 15(d)(i) and (ii) in future Estimates.

Study and Trial Plan

23. A Study and Trial Plan is attached at Enclosure 2 for Members' reference.

Implications for fees/charges

24. The amortised project cost of the CNS/ATM Systems will be recovered via the Air Traffic Control and En-route Navigation Services Charges. The cost of individual elements will be recovered in about 15 years after coming into operational use.

25. The CNS/ATM project would not result in any increase in these charges in the next six to seven years. For a few years after 2006-07, it is expected that there would be a modest increase in the costs of Air Traffic Control Services to be recovered from the Airport Authority (AA) as a result of the introduction of the CNS/ATM Systems. The increase is estimated to be less than 2% of the total annual operating costs of AA based on its present cost structure. The increase in the costs for En-route Navigation Services provided to aircraft overflying Hong Kong's flight information region is expected to be around 10%. The above increases would be more or less offset when the amortised project cost for the existing ground-based ATC systems has been fully recovered and taken out from the above costs. It should also be noted that even if there is no need for the introduction of the CNS/ATM Systems in compliance with the Global Implementation Plan, CAD would have to gradually upgrade or replace the existing ground-based systems to keep up with advancement in technology and growth in demand for ATC services. The proposal should have no significant impact on these costs in the long run.


26. The implementation of the CNS/ATM Systems is supported by the Aviation Advisory Board, the International Air Transport Association and the airlines. We briefed the Legislative Council Panel on Economic Services on the project on 2 March 1999. Members generally supported the need for the CNS/ATM Systems but asked for more detailed information to be provided when the proposal is submitted to the Finance Committee. This paper has set out the relevant information in greater detail.


27. Given ICAO's Global Implementation Plan and the need to maintain Hong Kong's position as a centre of international and regional aviation, we must introduce the satellite-based CNS/ATM Systems as what many other ATC authorities have been doing. It was stated in the Chief Executive's 1998 Policy Address that we would convert the current ground-based ATC and communications systems to satellite-based CNS/ATM Systems to enhance flight safety and efficiency. The target as contained in the 1998 Policy Objective Booklet of the Economic Services Bureau on Air and Sea Transport Infrastructure, Postal and Weather Information Services was to start studies in 1999 with a view to phased implementation of the new systems from 2003.

28. The purchase and design of the existing ATC systems at the new airport started in 1992 and therefore did not take into account the Global Implementation Plan published by ICAO in 1993. However, given the long lead time required for the full implementation of the CNS/ATM Systems, the existing

ATC systems will be actively utilised for many years to come. The existing ground-based radar will continue to be required to provide short range coverage to complement the satellite-based systems. As for the existing communications equipment, though some of them will eventually be replaced by the satellite communications system, they will be required in the transition period and be retained as backup until the end of their operational life. Hence, there will not be any pre-mature disposition of the existing equipment.


Economic Services Bureau
April 1999

Enclosure 1 to FCR(1999-2000)10

Study and Trial Phases of the
Communications, Navigation, Surveillance/Air Traffic Management (CNS/ATM) Project

Study Phase

Description Purpose/Function Major equipment/
Services to be acquired
Time-frame $ million
(in 1998-99
(a) Computer system for simulation modelling To perform simulation modelling study on Flow Management, Airspace Management, etc. High-capacity, high-speed computer systems, simulation software, LAN, printers, scanners, chart plotters, etc. 1999-2004 1.2

(b) Equipment for the evaluation of system configuration and implementation options, etc. To study/evaluate the performance of different system configurations for individual CNS/ATM elements including levels of backup and equipment site locations to meet the unique terrain and operational requirements in Hong Kong. Computer systems, site evaluation/modelling kit, satellite coverage evaluation tools, etc.(printers and scanners to be shared with item (a)). 2000-2004 1.0

(c) Fact-finding visits to equipment manufacturers and liaison with Hong Kong's aviation partners To gain technical and operational knowledge and experience in the development of CNS/ATM Systems, and to discuss matters such as the concerned international standards to be adopted. It is estimated there will be about 20 man-trips by staff members to visit overseas aviation authorities and manufacturers during the five-year period. The amount sought is to cover travelling expenses and subsistence allowance etc. arising from visits. 1999-2004 0.6

(d) Implementation progress database system To maintain an up-to-date database and record on the implementation progress of CNS/ATM elements by Hong Kong and other Asia Pacific Economic Co-operation economies. Computer systems, relational database management software, external bulk storage device, printers, etc. 1999-2004 0.5

(e) Contingency (10%)



Sub-total (Study Phase) 3.7


Trial Phase

Description Purpose/Function Major equipment/
Services to be acquired
Time-frame $ million
(in 1998-99 prices)
(a) Enhancements to Controller-Pilot Data Link Communications (CPDLC) trial system To make use of the uplink and downlink of satellite data for exchange of Air Traffic Control (ATC) instructions and pilot-controller communications, which is much more efficient and reliable than ordinary voice communication which is more susceptible to interruption or interference. Small ground earth station/equipment for up and down-links of satellite data, upgrading/modification of the CPDLC hardware and software to cover different functionalities and Man-Machine Interface (MMI) for system optimisation, etc. 2000-2003 8.0

(b) Satellite voice To replace the noisy High Frequency (HF) communications currently used for long range applications. Air-ground satellite communications equipment, interface facilities with the Speech Processing Equipment for evaluation by the air traffic controllers, etc. 2000-2004 3.0

(c) High Frequency/Very High Frequency (HF/VHF) Data Link To exchange ATC data between pilots and controllers with a view to replacing the less reliable voice communication.

Applications include pre-departure clearance delivery, ATIS (Automatic Terminal Information System)/Volmet (Meteorological) Data Broadcast, etc.

HF and VHF transmitters/receivers, data processors, display workstations, interface facilities with the standalone ATM system, data recording and playback facilities, printers, etc. 2000-2004 9.0

(d) Air Traffic Services (ATS) Interfacility Data Communication (AIDC) To exchange ATC information related to flight notification, flight coordination, transfer of control, surveillance data, etc. with ATC centres of other places.

Applications include notification of flights approaching a Flight Information Region (FIR) boundary, coordination of boundary conditions and transfer of control or communication, etc.

AIDC workstations, interface facilities with international communication circuits for connections with similar systems used by adjacent ATC centres, protocol converters, recording devices, modems, protocol/format generators, etc. 2002-2004 10.0

(e) Aeronautical Telecommunication Network (ATN) To cover the inter-networking infrastructure for the global aviation telecommunications network with a view to allowing data communications services for different user groups and eventually to encompassing all aeronautical data communication service users associated with the international aviation environment. Data communications switches, routers, data processors, interface facilities with all local systems to be connected to this network, gateway equipment to international service network to overseas aviation organizations, performance monitoring workstations, event logging devices, etc. 2003-2007 18.0

(f) Wide Area Augmentation System (WAAS) To broadcast the correction signals for aircraft to process the "erroneous" Global Navigation Satellite System (GNSS) satellite data to define its accurate position in air. The system can be upgraded to provide Category I precision landing function and thereby replace Category I Instrument Landing System. Master and reference ground earth stations, GNSS receivers, satellite data performance monitoring systems, correction signal data processors, display system, communication links with ATC centres and communication satellite systems, event logging devices, high speed printers, etc. 2000-2003 20.0

(g) Local Area Augmentation System (LAAS) Functions similar to those of WAAS except that LAAS would provide more accurate correction data to provide up to Category III precision landing function and replace Category II/III Instrument Landing Systems. High precision reference ground earth stations, high precision differential data processors, GNSS receivers, satellite data performance monitoring systems, display system, VHF data link transmitters and receivers, event logging devices, etc. 2004-2007 25.0

(h) Mode "S" Secondary Surveillance Radar(SSR) To enable individual addressing to each aircraft with uniquely allocated identification code and to provide the capability of transmitting digital data between air and ground on air temperature, wind speed, wind direction, airport and runway serviceability status, etc. Modification to existing SSR to include aircraft selective addressing facility, ATC workstations for Mode S operation, additional channelling cards on existing microwave link systems, Mode S data recording system, etc. 2000-2005 10.0

(i) Automatic Dependent Surveillance (ADS) Enhancements To provide aircraft position in air through satellite and VHF data links, for air traffic controllers for closer monitoring and/or control of aircraft movements, particularly in areas outside radar coverage. Small ground earth station/equipment for up and down-links of satellite data, upgrading/ modification of the ADS hardware and software to cover different functionalities and MMI for system optimisation, etc. 2000-2003 6.0

(j) Enhanced Ground Movement Control System (EGMCS) To provide more positive and accurate surveillance of moving targets on or adjacent to the airfield, e.g. taxiway, apron, runway, sea area (as applicable in Hong Kong) for aircraft, vehicles and ships and to provide runway intrusion alert. Upgrading of Surface Movement Radar (SMR) to provide target interrogation functions, transponders on ground vehicles, software development/modifications on the SMR workstations, etc. 2004-2007 17.0

(k) Air Traffic Management (ATM) functions (Integrated Global ATM System) To merge and provide various ATM functions like -

ADS Data Processing;Conflict Alert;Minimum Safe Altitude Warning;Flow Control Management;Conflict Prediction;Arrival Metering, Sequencing and Spacing;Trajectory Conformance Monitoring, etc.

This would enable aircraft operators to conduct their flights in accordance with their preferred trajectories, dynamically adjusted, in the most optimum and cost-efficient manner.

Standalone high capacity ATM system with ADS/radar data processors, data communications network and advanced display systems, interface facilities with relevant CNS systems, software development/modification for various ATM functions, radar/ADS data recorders, etc. 2003-2007 20.0

(l) Ancillary systems relating to systems (a) to (k) For the trial operations and evaluation of the systems listed in (a) to (k) in a complete user working scenario. High precision timing systems, data phone system, advanced intercom facilities, high capacity voice recording devices, data emulators, technical consoles, etc. 2000-2007 8.0

(m) Contingency (10%)



Sub-total (Trial Phase ) : 170.0


Total (Study and Trial Phases) : 173.7


Price adjustment : 24.2

Total (in money-of-the-day prices) : 197.9


Note : Allocation among different cost items is subject to adjustment as studies and trials progress.

Enclosure 2 to FCR(1999-2000)10