FIR
Flight Information Region
Last updated: April 20, 2026 · Maintained by Aviatr Editorial Team
What is FIR?
A FIR (Flight Information Region) is a defined volume of airspace in which a single authority provides flight information service and alerting service for all traffic. FIRs are ICAO's highest-level airspace division, and every point in the world's airspace falls within exactly one FIR.
How is FIR used?
Pilots filing IFR flight plans list the FIRs their route traverses — a flight from Frankfurt to Istanbul crosses the Langen, Vienna, Budapest, Sofia, and Istanbul FIRs, requiring frequency changes and handoffs at each boundary. FIR boundaries generally follow national borders, geographic features, or traffic-flow patterns rather than simple latitude-longitude lines. In oceanic regions, FIRs such as Shanwick and Gander govern the North Atlantic Track System, where radar coverage is absent and position reporting relies on pilot voice reports and ADS-C data links. FIR authorities also coordinate search-and-rescue operations within their assigned area and are the first point of contact for emergencies in uncontrolled airspace. VFR pilots operating outside controlled zones receive flight information service from the surrounding FIR's flight information centre, which can relay weather, NOTAMs, and traffic information on request.