Definition
A published, step-by-step procedure that guides a pilot from the en route portion of a flight down to a point near the runway using only cockpit instruments and ground- or satellite-based navigation aids. Each procedure specifies the route to fly, altitudes to maintain, navigation sources to use, minimum altitudes, and the missed approach instructions if a landing cannot be completed.
Plain English
A printed flight plan for landing in poor visibility. It tells the pilot exactly which path to fly, how low to descend, and what to do if they can't see the runway when they get there.
Context Anchor
Seen on instrument approach charts, in air traffic control clearances, and in the FMS when selecting or loading an approach to a runway.
Derivation
Approach comes from the Old French aprochier, meaning to come near. An instrument approach is the procedure for coming near the runway when the pilot must rely on instruments rather than outside visual references.
Why Pilots Care
Provides the precise guidance needed to complete a safe landing when visibility is too low for visual approaches.
Intuition Check
An IAP is not just any approach to an airport. It is a published, charted procedure with specific instructions and limits.
Example Sentence 1
With the ceiling reported at 600 feet, the crew briefed the ILS instrument approach procedure for Runway 27.
Example Sentence 2
Before starting descent, the crew reviewed the full IAP to confirm altitudes and fixes.