Definition
A series of predetermined maneuvers, published by the FAA, that allow a pilot to descend safely from the en route altitude to a point near the runway using only flight instruments and navigation aids, when visibility or cloud cover prevents visual approach. Each IAP specifies the route, altitudes, headings, descent profile, and required navigation equipment for a specific runway at a specific airport.
Plain English
A step-by-step set of instructions that guides a pilot down to the runway when they cannot see the ground clearly. The pilot follows the published path, altitudes, and turns using cockpit instruments instead of looking outside.
Context Anchor
You see IAPs on instrument approach charts, in instrument training, in IFR flight planning, and when air traffic control clears an aircraft for an approach.
Derivation
"Approach" comes from the Latin appropiare, meaning "to come near." "Procedure" comes from the Latin procedere, "to go forward." Together the term describes a forward-going, near-the-airport sequence — a defined path for getting close to the runway when you cannot rely on your eyes.
Why Pilots Care
These procedures make landings possible and safe in weather that would otherwise force a diversion, and they form a required part of every instrument flight plan to equipped airports.
Grounding Statement
Picture a pilot in clouds following a published approach chart that tells them where to fly, how low they may go, and what to do if the runway does not come into view.
Intuition Check
An instrument approach is not just any arrival at an airport. A procedure is not a suggestion; it is a published, approved path and set of actions the pilot is expected to follow exactly.
Example Sentence 1
With the field reporting a 400-foot ceiling, the pilot briefed the ILS instrument approach procedure for Runway 27 before beginning the descent.
Example Sentence 2
When the runway stayed hidden at the missed approach point, the crew followed the published Instrument Approach Procedures to climb and hold for another attempt.