A flight information service (FIS) is a form of air traffic service which is available to any aircraft within a flight information region (FIR), as agreed internationally by ICAO.
It is defined as information pertinent to the safe and efficient conduct of flight, and includes information on other potentially conflicting traffic, possibly derived from radar, but stopping short of providing positive separation from that traffic.
In aviation, a flight information region (FIR) is a specified region of airspace in which a flight information service, an alerting service (ALRS), and an area control centre are provided. The International Civil Aviation Organization (ICAO) delegates which country is responsible for the operational control of a given FIR. FIRs are the largest regular division of airspace in use in the world today, and have existed at least since 1947.
Smaller countries' airspace is encompassed by a single FIR; larger countries' airspace is subdivided into a number of regional FIRs.
Air traffic management (ATM) aims at ensuring the safe and efficient flow of air traffic. It encompasses three types of services:
The Chicago Convention 1944 (52 signatory states) required each state to provide air navigation services for their own state and early air navigation service providers (ANSPs) were state-controlled monopolies. En-route navigation is still offered by state-run monopolies although in Europe since 1997 they were under a performance review framework and since 2009 and 2013, under performance and risk-sharing charging regulations.