Instrument Flight Rules (IFR)

Rules governing the procedures for conducting instrument flight. Also a term used by pilots and controllers to indicate type of flight plan. (PCG definition).

Rules and regulations established by the Federal Aviation Administration to govern flight under conditions in which flight by outside visual reference is not safe. IFR flight depends upon flying by reference to instruments in the flight deck, and navigation is accomplished by reference to electronic signals. (PHAK definition)

Source: Pilot Contoller Glossary (PCG), Pilot Handbook of Aeronatical Knowledge

See also: