Flight Information Region

A Flight Information Region (FIR) is an aviation term used to describe 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.Any portion of the atmosphere belongs to some specific FIR. Smaller countries' airspace is encompassed by a single FIR, larger countries' airspace is subdivided into a number of regional FIRs. Some FIRs may encompass the territorial airspace of several countries. Oceanic airspace is divided into Oceanic Information Regions and delegated to a controlling authority bordering that region. The division among authorities is done by international agreement through ICAO.
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An airspace of defined dimensions within which Flight Information Service and Alerting Service are provided. (FAA4)

An airspace of defined dimensions within which flight information service and alerting service are provided. See also air traffic control centre; area control centre. 1/3/73

Espace aérien de dimensions définies, à l'intérieur duquel sont assurés un service d'information de vol et un service d'alerte. Voir aussi centre de la circulation aérienne; centre de contrôle régional. 1/3/73

An airspace of defined dimensions within which Flight Information Service and Alerting Service are provided.
a. Flight Information Service. A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.
b. Alerting Service. A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid and to assist such organizations as required.