What Is FIR? Definition & Meaning in Aviation
A FIR (flight information region) is a defined block of airspace in which a country, or a group of countries, provides air traffic and alerting services.
In plain language
The world’s airspace is divided into FIRs. Aircraft talk to the controllers of the FIR they are in and are handed over at the boundary.
Example
Pakistan’s airspace is managed as two FIRs, the Karachi FIR and the Lahore FIR, so an aircraft crossing the country is handed from one to the other.
Why it matters
The FIR determines which controllers handle a flight and where handovers occur. It also explains why aircraft crossing Pakistan talk to different centres, and why airspace decisions in one FIR can ripple into flight times.