Definition
A flight conducted in accordance with Instrument Flight Rules, in which the pilot navigates and controls the aircraft primarily by reference to flight instruments rather than by looking outside. The flight is operated under an IFR clearance issued by air traffic control, who provides separation from other IFR traffic and, in controlled airspace, from terrain and obstacles via assigned routes and altitudes.
Plain English
A flight where the pilot flies by the instruments and follows directions from air traffic control, instead of relying on looking out the window. ATC keeps the aircraft separated from other traffic.
Context Anchor
Seen in flight plans, weather decisions, air traffic control communication, instrument training, and instrument flight procedures.
Derivation
IFR stands for Instrument Flight Rules. 'Instrument' here points to the cockpit gauges the pilot uses to know attitude, altitude, heading, and position when outside cues are missing. Knowing this makes it clear that an IFR flight is defined by how the pilot navigates and is regulated, not by the weather alone.
Why Pilots Care
Allows continued safe flight through clouds, fog, or low visibility and is required for operations in controlled airspace under IMC or above certain altitudes.
Intuition Check
An IFR flight does not always mean the weather is bad. A pilot can fly IFR in clear weather if the flight is being conducted under Instrument Flight Rules.
Example Sentence 1
She filed an IFR flight from Oakland to Reno because a layer of clouds was forecast along the route.
Example Sentence 2
During the IFR flight the controller issued a descent clearance to the initial approach fix.