THE HELLENIC ATC SYSTEM
(modernisation program)

by Mr Chr. Galiouras

System development history

The new Hellenic air traffic control (ATC) system has been in operation since the 11^th February 1999. This means the operation of a new ATC centre housing the two Area Control Centres (Athens and Macedonia) and a new Tower for the Aerodrome Control (TWR) and beneath it the Approach Control (APP), serving Athens airport. This also means a transition from a procedural based control system to a sophisticated automated environment utilising processed radar and flight plan data.

The new system has been developed in the frame of a modernisation program implemented by a contract signed in 1991, between the Greek State and the company Thomson-CSF (Airsys - ATM), for the delivery of the following systems:

• PALLAS (Phased Automation of the Hellenic ATC System) for the radar and flight data processing and operator input and display functions

• HERAS (Hellenic Radar System) for the enroute radar part of the program including four stations at Himittos (PSR/MSSR), Pilion (MSSR), Lefkas (MSSR) and Kithira (MSSR).

• ATARS (Athens Terminal Area Radar System) for the surveillance function in the Athens TMA. The system replaced the old radar system operating since 1968.

• SIMULATOR, for air traffic controllers training

• AFTN for messages switching and distribution with CIDIN functions

• VAR (Voice Communication System, Ancillary Equipment and Remote Control System) for the communication part of the program consisting of 9 subsystems.

A sophisticated System for overall System Monitoring and Control (SMC) and a Central Workshop (CWS) for the repair of faulty or damaged items supplement the program.

The new ATC centre can operate with a configuration of up to 15 sectors, each one having three working positions while the configuration of the new Athens APP consists of 8 working positions and that of the Athens TWR consists of 5. All “executive” working positions are equipped with high definition colour displays 2kX2k.

The new environment is an outcome of the implementation mainly of the PALLAS system, which has the following characteristics :

- fully automated and integrated system

- duplicated RISC processors

- open architecture, industrial standards, based on the EUROCAT 2000

- graceful degradation modes

- acquisition and processing of up to 14 radars (approach and long range by providing raw and synthetic video)

- radar data processing with multiradar tracking and alert facilities such as :

-short term conflict alert

-minimum safe altitude warning

-danger area infringement warning

-cleared level adherence monitoring

-automatic collection and processing of flight plans issued from AFTN,RPL and Local Operators

-high flexibility with off-line adaptation of flight processing

-automatic flight progress monitoring (continuous calculation of flight profile and update based on radar data)

-electronic and paper strip presentation

-automatic allocation of SSR codes

-silent co-ordination

-connection to adjacent centres (four OLDI, X25 lines)

-connection to four regional approach centres

-reception from meteo computer taking into account weather conditions into the FIR

-civil/military flights co-ordination

-air situation play-back function for incidents investigation, test and training

-HMI issued from prototyping with ATCOs and ergonomic study

-test and development platform

-benchmark position

The VAR system provides the vital tool of communications which has the following characteristics:

- main/stand-by

- 85 operator positions

- 160 telephone lines

- 56 radio channels

- 11 remote radio station sites

- 4 back-up frequencies

- 50 back-up telephone lines

Benefits of the new system

Customer services mean safety, efficiency, and punctuality. Capacity bottlenecks must be reduced to accommodate the current traffic figures as well as the future growth rates. The new ATC system complies with our customers’ wishes for capacity increase.

More than 400.000 operations in the Hellenic airspace and more than 145.000 movements take place annualy in the Athens airport, experiencing important delays in the past, during peak periods, resulting from the limited capabilities of the old system.

After seven months of operation, the new system has been giving quite impressive results. During the peak months (July and August) a delay reduction, ranging from 64 to 82% (on a weekly basis), is recorded compared with the same period of 1998. This reduction is considered to be highly important taking into account the fact that it has been achieved during the initial operation of the system. During this phase of operation an increase in delays is usually anticipated since a familiarisation period is required before establishing an effective operation of the system.

In addition to the delay reduction, an increase of 12-16% of the handled traffic was recorded. This increase of traffic was in a certain degree expected considering that in the highly competitive air traffic management market this change (automation- delay reduction) is highly appreciated.

The operation of the new ATC system effectively contributes to the achievement of the objectives of the Convergence and Integration Plan in the framework of EATCHIP, in line with the commitments of the Hellenic Civil Aviation Authority. This achievement upgrades the role of the Hellenic system in the area as far as efficiency and safety are concerned.

The radar station network which will be enhanced by the use of three additional MSSR stations (PHAROS project) and the, already installed, radar systems in the four main regional airports (PATROCLOS project), will ensure a more than double coverage all over the entire airspace. This will upgrade the safety element and it will significantly improve the efficiency of the system. By establishing new navigation routes and direct routes within Athens and Macedonia FIR/UIR, a more effective use of the airspace is achieved, as a benefit from the available coverage. This ensures the most possible efficient flight profile and it alleviates congestion.

The radar coverage and the advanced data processing reduce the workload for both controllers and pilots. The new ATC system enables the controllers to manage the airspace more effectively and efficiently and greatly improves their working conditions. At the same time it serves as an incentive for the personnel, upgrading their level of the professionalism and productivity.

The SIMULATOR, being in operation since early 1995, was proven to be an excellent tool for the development of the required skills and the controllers' qualification (both for area and approach). The facility is equipped with advanced hardware and software tools, based on the PALLAS features. It is used so far not only for training controllers involved in the operation of the new system but also for controllers of the 4 peripheral airports, where the process for a phased introduction of radar function is currently in progress.

The future

The operation of the new ATC system is a major step to fill the gap in technology and the gap between a procedural and an automated system. The efforts shall continue in order to cope with the needs for continuous improvement, the continuous increase of air traffic, and the need for a constant enhancement of ATC facilities.

This effort is reflected in a number of projects which now are in the planning or the implementation phase.

The PATROCLOS project comprises the installation of four terminal radar stations (PSR/MSSR), the associated processing and display systems and four Voice Communication Systems at the four main peripheral airports (Thessaloniki/Makedonia, Kerkira/I.Kapodistrias, Iraklion/N.Kazantzakis, Rodos/Diagoras)

These systems will become operational in a phased implementation, currently being in the test phase.

The URANIA project is developed in parallel with the construction of the New Athens International Airport at Spata, which has already started. The main aim is the implementation of all the air navigation systems for the new TWR and the upgraded Athens APP. Operation of these systems is planned for October 2000; the new airport will start operations in March 2001.

The PHAROS project comprises the installation of three new en route radar stations in order to ensure at least a continuous duplicated SSR and single PSR coverage for en-route surveillance. The project is in the implementation phase.

The PALLAS UPGRADE project will enhance the functionalities of the PALLAS system.

The AIS, the HELLANET and the SAFETY MANAGEMENT projects, being in the planning phase, are also parts of the global modernisation program.

Finally since the operation of any of the above systems is strongly dependent on the available human resources a plan is developed for staff recruitment to cover these needs. Within this framework 41 controllers were recruited on July 1999. A recruitment of 140 more will follow.

As a result of all these initiatives the Hellenic Air Traffic Services are in a position to provide safe and more efficient ATC capacity at a reasonable price and to operate an ATC system as part of the European ATC concept and serving as a critical centre for the EATCHIP Program.

As a result of the same initiatives the Hellenic Civil Aviation Authority contributes to the upgrading of the efficiency and effectiveness of the Hellenic air transport system .

Finally the same initiatives allow for the benefits of the geographical position of the country to be fully exploited. As a crossroads of numerous traffic flows and operating as a link between Europe and two other continents Greece is expected to constructively contribute to the international aviation community.