ATM Modernization, Business & GA, Commercial

An ATC Upgrade of Olympian Size

By George Marsh | April 1, 2001
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Athens, city of antiquity and tourism, has a new airport–one fit for the 21st century, and for the Olympic Games that the city will host in 2004. Due to be inaugurated this spring, Eleftherios Venizelos (named for a former prime minister) Airport at Spata, will take over from the previous Athenia International at Hellinikon. After six decades, Athenia, located nine miles (14.5 km) south of Athens city, just cannot expand any further.

Impressive enough with its two parallel runways, 223-foot (68-meter) tall control tower and modern terminal buildings, the new Athens International is nevertheless part of a larger modernization scheme. Over the last decade Greece has been upgrading its airport and air traffic service (ATS) provision in line with Eurocontrol philosophy and the expanding demand for air transport in this pivotal southeastern corner of the European Union. The upgrade has involved phased automation of the Hellenic air traffic control (ATC) system plus implementation of new en route and terminal area radars, AFTN (Aeronautical Fixed Telecommunications Network) message switching, a complete communications suite that includes radio equipment and a voice communications control system (VCCS), and a simulator for controller training. Navigational aids have been added. Even the existing airport at Hellinikon was upgraded to meet late 20th century needs right up to the moment it closes.

Central to this modernization effort has been German, French and British expertise, since Thales ATM (formerly Airsys ATM) has provided and installed the lion’s share of the equipment since 1991. As a turnkey supplier, it also has managed much of the program.

The modernization program revolves around a new ATC complex, housing two area control centers (Athens and

Macedonia) and a new tower in which aerodrome control and, beneath it, approach control have been installed to serve Athens Airport. The new ATC complex can operate with a configuration of up to 15 sectors, each having three working positions. Aerodrome control has 15 controller workstations, while approach control has five. The working positions are equipped with high-definition 2K-by-2K color displays in a Eurocat 2000 system produced by Thales ATM.

Maintaining the momentum of the Hellenic Civil Aviation Authority’s (CAA’s) PALLAS (phased automation of the Hellenic ATC system) project, the new air traffic control complex can acquire and process raw and synthetic data from up to 14 approach and long-range radars. An open architecture provides flexibility for future additions and upgrades.

Dionyssios Kalofonos, former Governor of the Hellenic CAA (recently replaced by Athanasios Trogan), says that controllers, used to the previous procedurally-based manual system, are adapting well to a sophisticated automated environment. "Automatic features like flight progress monitoring, secondary surveillance radar [SSR] code allocation, and alerting [traffic conflicts, minimum safe altitude, danger area, etc.] ease their workload, helping to increase traffic throughput at peak times," he adds.

Flight progress data can be presented to controllers in electronic or paper strip formats. The system automatically collects flight plans emanating from AFTN telecommunications, the repetitive flight plan management system, and local operators. It then processes the plans, with high flexibility for off-line adaptation. Controllers can access weather conditions within the flight information region (FIR) from the Met (meteorological broadcast service) computer and connect as necessary to adjacent control centers and to four regional approach centers. Recorded voice traffic and other data can be played back for training or incident investigation.

Kalofonos feels confident that these capabilities will succeed in meeting initial traffic targets of up to 600 aircraft movements per day in the FIR. These movements account for some 16 million passengers a year, up from the 11 million or 12 million limit imposed on the old airport. Room reportedly exists for expansion to eventually accommodate some 50 million passengers a year.

Greece’s renewed communications infrastructure comprises a TXM 4400 VCCS, produced by Thales ATM, along with HF/VHF/UHF radiocommunications. These units represent the core element of the Helenic CAA’s VCS (voice communication system) ancillary equipment and remote control system (VAR), which has nine subsystems. VAR provides controllers at 85 operator positions access to a mix of communications from 160 phone lines, 56 radio channels, and 11 remote radio sites. In addition, there are 50 back-up phone lines and four back-up frequencies. VAR’s remote control element permits central monitoring and control of a widely dispersed range of ATC facilities both on and off the airport. VAR was the final system to be delivered in a program phase that Greece’s CAA approved in March 1998.

ATC voice communication support systems include a communications recording system and closed circuit television. AFTN is installed for message switching and distribution within the Common ICAO Data Interchange Network (CIDIN).

Navaids for Greece’s ATS include new DVOR/DME, ILS/DME and non-directional radio beacon installations. A new Doppler VOR has gone into the Korinthos region, west of Athens.

Lead Player

Supervised by the Hellenic CAA and the German consortium responsible for constructing the new airport–Hochtief (leader), ABB Calor Emag, and Krantz-TKT–Thales ATM has been charged to supply, install and integrate much of the equipment, especially at Athens Airport. Ordered by the consortium under three contracts in 1999, all of the new provisions had to be operational, integrated with the Greek ATC infrastructure, and ready to run in time for the spring 2001 deadline.

These orders, following a previous contract to supply two approach radars, made Thales ATM the predominant player in the Greek modernization effort. Other companies involved include Alenia and Garex, which upgraded ATC facilities at four major regional airports: Thessalonika, Rhodes, Heraklion and Kerkyra (PATROCLUS project). Among the improvements, they installed terminal approach radars, new voice communications, and new flight-data processing systems.

Still more was provided by sub-contractors, including a fiber optic network to carry voice and video, plus air traffic management (ATM) and local area communications. Florida-based Milgo Solutions engineered the 155 Mbit/s broadband network. Called the Premnet 5000, it is central to eight fiber rings delivering 1.2 Gbit/s of bandwidth with substantial redundancy. The system includes Cisco hardware, Milgo ALM 3239 modems, and a CMS 400 network manager.

A significant part of Thales ATM’s task has been to add five long-range radars in various parts of the country (see side bar on page 22). Commissioned to augment HERAS, the Hellenic Radar System, the equipment includes an L-band primary surveillance radar with co-located monopulse secondary surveillance radar (MSSR) at Himittos, together with individual MSSRs at Lefkas, Kithira and Pilion. The radar network will more than double coverage over Greece’s entire airspace and support reduced separations between aircraft, while new navigation routes, some direct, become established within the Athens FIR/upper information region (UIR).

All new surveillance radars are in addition to a terminal radar supplied under the Athens Terminal Area Radar System (ATARS) project. It was installed in 1996 to replace a 30-year-old system. Also placed at Athens Airport is an advanced surface detection equipment (ASDE) radar.


The Eurocat 2000 at the Athens control centers, with its human-machine interface (HMI) and architecture, automatically processes surveillance and flight data, and presents aircraft track and status on large, high-definition color displays. Targets are tagged with their identities (confirmed by SSR returns), intentions and clearance status. Windows pop-up with incipient conflict alerts, plus advisory information from Aeronautical Information Services (AIS), Met and other sources. A record and playback facility meets statutory requirements for subsequent incident review, together with training needs.

The Eurocat 2000’s surveillance data processing provides advanced radar tracking in vertical and horizontal dimensions and shows a clear, synthetic air-situation display from raw radar returns. The system has automatic dependent surveillance (ADS) tracking capability, and will handle the radar/ADS transition. Weather data also is integrated.

Flight data processing predicts flight trajectories from flight plans and actual flight status. Flight plans are received and processed automatically, and so are telecommunications messaging, predeparture clearances and the handling of air-ground data link. The Eurocat 2000 system allows coordination between civil and military controllers, between control sectors, and between FIRs.

Athens’ FIR–one of the region’s busiest–currently handles 400,000 flights per year. Upgrades to the infrastructure over the last decade, and particularly over the last three years, will see that capacity significantly increased with reduced delays and improved service reliability.

And just in time. With three years to settle down into glitch-free operation before the Olympic Games, the country that started the Games centuries ago should be ready for the 2004 air travel invasion.

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