Definition
Instrument Approach Procedure charts are published charts that depict the step-by-step procedure a pilot must follow to descend from the en route or arrival environment down to a runway, or to a point from which a landing can be made, using only flight instruments and ground-based or satellite navigation aids. Each chart shows the routing, altitudes, navigation frequencies, communication frequencies, minimum descent altitudes or decision altitudes, missed approach instructions, and airport details for one specific approach to one specific runway.
Plain English
These are the printed or digital charts pilots use to fly an instrument approach into an airport. The chart tells the pilot exactly where to fly, how low to descend, what radio frequencies to use, and what to do if the landing has to be abandoned.
Context Anchor
Seen during instrument flight planning, arrival briefing, and the transition from a STAR to an approach at the destination airport.
Derivation
Approach comes from the Old French aprochier, meaning to come near. An instrument approach procedure is a defined set of steps for coming near the runway using instruments rather than visual cues.
Why Pilots Care
They supply the exact vertical and lateral guidance needed to complete an approach safely in instrument conditions.
Intuition Check
Do not think of an IAP chart as just a map of the airport. It is a step-by-step published procedure for flying the approach safely and legally.
Example Sentence 1
Before starting the descent, the pilot pulled up the IAP chart for the ILS approach to runway 27 and briefed the minimums and missed approach point.
Example Sentence 2
After the approach clearance, the crew cross-checked the altitudes shown on the IAP charts against the altimeter.