Shannon FIR is the Flight Information Region

Flight Information Region

In aviation a flight information region is a region of airspace with specific dimensions, in which a flight information service and an alerting service are provided. It is the largest regular division of airspace in use in the world today....

 (FIR) for the country of Ireland

Republic of Ireland

Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

. The Irish Aviation Authority

Irish Aviation Authority

The Irish Aviation Authority is a commercial semi state company employing approximately 700 people at six locations around Ireland. The IAA has two main functions; the provision of air traffic management & related services in Irish controlled airspace and the safety regulation of the civil...

 is responsible for providing Air Traffic Control

Air traffic control

Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

 in this area and for regulating Irish aviation.

Its ICAO code is EISN.

Its boundaries are from surface to flight level

Flight level

A Flight Level is a standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the International standard pressure datum of 1013.25 hPa , the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either...

(FL) 660. The class G airspace exists outside the Control Zones (CTR's - Class C Airspace) and Control Areas (CTA's - Class A & C Airspace), up to FL75. The high level (FL245-FL660) above the area around Donegal Co., is controlled by the Scottish Control (EGPX).

The Shannon FIR contains the SOTA (South Oceanic Transition Area) and NOTA (North Oceanic Transition Area), as of the start of 2006. The airspace there is FL55-FL660. Just like in rest of the FIR, the airspace there is class C up to FL200 and Class A, FL210 up to FL660.