Shanwick Oceanic Control

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Shanwick Oceanic Control Area

Shanwick is the Air Traffic Control (ATC) name given to the area of International Airspace which lies above the northeast part of the North Atlantic.

Responsibility for the provision of air traffic services within International Airspace is delegated to UN Member States by the International Civil Aviation Organisation (ICAO). ICAO divides such airspace into Flight Information Regions, parts of which may be deemed Controlled Airspace and, where appropriate, classified as an Oceanic Control Area (OCA).

The name Shanwick is a portmanteau of the two air traffic facilities jointly concerned with flights operating within this particular area of International Airspace. First, the Ballygirreen Radio Station, 6 miles North of Shannon Airport in County Clare, (near Limerick), Republic of Ireland, and the Prestwick Oceanic Area Control Centre (OACC) in Ayrshire, (near Glasgow), Scotland.

The flight control (Procedural ATC) aspect is the responsibility of the United Kingdom and is provided by NATS from the Prestwick OACC, while the voice communication aspect is the responsibility of the Republic of Ireland and is provided by the Irish Aviation Authority (IAA) from the Ballygirreen Radio Station based Shannon Aeradio.

Shannon Aeradio keeps in radio contact with all flights within the Shanwick OCA by means of HF radio. 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. Shannon Aeradio, callsign "Shanwick Radio", uses over 20 HF frequency channels and 2 VHF. At peak times it handles in excess of 1300 aircraft in a 24 hour period. (The Prestwick OACC, callsign "Shanwick Control", uses 2 VHF frequencies and an ACARS based system called ORCA - Oceanic Route Clearance Authorisation, exclusively for the issue of Oceanic Clearances to westbound flights about to enter the Shanwick OCA).

In 2003, NATS announced that is was investing £300m to build a new ATC centre at Prestwick which will eventually house both the Prestwick OACC and Scottish Area Control Centre (ScACC), together with the Manchester ACC, which is currently located at Manchester Airport, Manchester, England. The new Prestwick Centre is due to commence handling flights in early 2010. (The existing ATC centre at Prestwick, home to both the Prestwick OACC and Scottish ACC, is known as ScOACC - the Scottish and Oceanic Area Control Centre). RAF Prestwick, home of the "Scottish Air Traffic Control Centre (Military)", is also housed at ScOACC and will likewise move into the new Prestwick Centre.

Prior to the opening of the new Prestwick Centre, the Prestwick OACC moved into a temporary building in November 2006 to commence operations with the new joint NATS/NAV CANADA designed Oceanic ATC computer system known as SAATS - Shanwick Automated Air Traffic System. SAATS having been developed from NAV CANADA's GAATS - Gander Automated Air Traffic System. (Gander International Airport, Newfoundland, Canada, being the location of NAV CANADA's ATC center responsible for flights in the northwest part of the North Atlantic).

During 2005/6 upgrades to Shannon Aeradio equipment at Ballygirreen took place and the IAA entered into an agreement with the Icelandic Civil Aviation Administration's Gannet ATS COM to provide additional HF communication services within the Shanwick OCA via the Gufunes Telecommunications Centre, (near Reykjavík), Iceland.

Trans-atlantic traffic has been steadily growing over the years and this growth is expected to continue. In 2004, 351,588 aircraft crossing the North Atlantic, on both random routes and North Atlantic Tracks, communicated with air traffic controllers at the Prestwick OACC via Shannon Aeradio. However, increasing numbers of aircraft operators are utilising Datalink communications, Future Air Navigation Systems and forwarding waypoint position reports via Automatic Dependent Surveillance, (ADS-C & ADS-B), or Flight Management Computer. As a result of these technological developments, fewer flights now require to use HF radio in order to communicate with ATC.