Air Traffic Management

North Atlantic Communications Service

The IAA's North Atlantic Communications Service is provided from its communication station located at Ballygirreen, Newmarket-on-Fergus, Co. Clare and covers the Eastern half of the North Atlantic. It is known as Shannon Aeradio, or Shanwick Radio (ICAO Code: EIAA).  Approximately 70 personnel are employed at the North Atlantic Communications centre, including over 55 Radio Officers with the remainder involved in management, engineering, administration and other services.

North Atlantic Communications Centre
North Atlantic Communications Centre, Ballygirreen, Co. Clare

Aeronautical Services at North Atlantic Communciations

1.     Aeronautical Mobile Service - Air/ground operations (Shanwick Radio)

Shanwick Radio provides a long range voice communications service for Oceanic Air Traffic Control in the eastern half of the North Atlantic. The Shanwick Oceanic Air Traffic Control Centre is located at Prestwick in Scotland, hence the name Shanwick (Shannon/Prestwick).

Shanwick Radio keeps in contact with all flights in Oceanic Airspace mainly by means of High Frequency Radio (HF), but also uses VHF (Very High Frequency) and Satellite Phone (SATPHONE). HF can provide global coverage because of its ability to bounce off the ionosphere and can span the globe in a series of skips. VHF coverage, on the other hand, is limited to line-of-sight range. Shanwick Radio uses over 20 HF frequency channels and 2 VHF. At peak times it handles in excess of 1400 aircraft in a 24 hour period.

In 2013, the station handled in excess of 1 million messages from 404,842 aircraft. To cater for the growth in HF frequency activity, additional frequencies will be added in the near future.

Investment in Technology

In recent years the IAA has invested significantly in new systems providing the North Atlantic Communications operation with state-of-the-art facilities and bringing the service up to the most modern standards. A new suite of transmitters and receivers has been installed and the Air-Ground message processing and flight data system replaced.

            Shanwick RO           

A Shanwick Radio, Radio Officer operating the ROFDS.

This system, known as the ROFDS (Radio Officer Flight Data System), which is linked to a similar system in the Iceland Radio centre, has enabled the Irish Aviation Authority and ISAVIA (the Icelandic Civil Aviation Administration) to provide joint radio operations for the Shanwick and Reykjavik/Sondrestrom Oceanic areas.  Formal agreement between the two companies was signed in 2004, and in April 2006 joint operations commenced creating, in effect, one virtual Radio Communications service provision for the North Atlantic from 45N to the North Pole.  Radio officers in either centre work flights in either area, updating both systems seamlessly and transparently for the respective Control Centres in Reykjavik and Prestwick.

Gufunes Ops Room

Gufunes Communications Operations Room

The next phase of the Joint Operations will increase the interoperability whereby operational staff in both centres will have access to each other’s Transmitters, Receivers and associated equipment through interconnectivity. This will bring substantial enhancements to the existing Joint Operations and deliver a safe, efficient and cost effective service to the NAT airlines.

 2.     Aeronautical Fixed Service - AFTN

In addition to the North Atlantic Communications Service, Shannon Aeradio is the AFTN COM Centre for Ireland. The Aeronautical Fixed Telecommunications Network (AFTN) is an international telegraphic service linking airline offices, ATC and meteorological services worldwide. All AFTN communications both in and out of Ireland are routed through the Ballygirreen AFTN switch.

            New AMHS System

The Ballygirreen AFTN switch has been upgraded to the Frequentis smartMessenger AMHS solution. This system will come into operation in the Autumn of 2012.  The system, in time, will be connected to international AMHS centres around Europe.


3.     Aeronautical Broadcast Service - Volmet

Another service provided to the aviation community from Shannon Aeradio, is the Volmet Broadcast Service. This is a 24 hour, 365 day-a-year continuous broadcast of weather data to aircraft in flight. The data consists of SIGMET’s (warnings of significant weather phenomena which may be hazardous to aircraft), terminal forecasts and actual weather observations for each of the principal airports in Europe. These reports are updated every 30 minutes. The broadcast goes out on three HF and one VHF frequency simultaneously.

Winter Schedule         

1 November - 31 March


Day 1200-1800z




Night 1800-1200z




Summer Schedule    

1 April - 31 October    


Day 1000-2200z




Night 2200-1000z




 Shannon Volmet Frequencies and Schedule

Dublin Volmet is broadcast on 127.0MHz

Internal Systems

Information Display System (IMDS)

NAC is equipped with the one of the most modern Information Management and Display System’s (IMDS), the Copperchase IMDS.  This system updates all operational staff with the dynamic information, including NAT Tracks and NARTEL frequencies, that Radio Officer’s require to perform their key role. It also has the capacity to display maps and charts of the North Atlantic including the Reykjavik and Sondrestrom flight information regions as part of the Joint Operations with Iceland.  An electronic Self-Briefing tool is also part of the IMDS.


Copperchase IDS


Voice Record and Replay System (VRSS)

The Voice Recording System, supplied by AudioSoft, UK, provides increased functionality, aids frequency monitoring, playback and incident investigation and fulfills ICAO data retention requirements


AudioSoft VRSS


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