Definition
A series of predetermined maneuvers by reference to flight instruments with specified protection from obstacles, from the initial approach fix (or where applicable, from the beginning of a defined arrival route) to a point from which a landing can be completed and thereafter, if a landing is not completed, to a position at which holding or en route obstacle clearance criteria apply. Under ICAO classification, instrument approach procedures are categorized as a precision approach procedure (PA) using precise lateral and vertical guidance with minima determined by the category of operation, an approach procedure with vertical guidance (APV) using lateral and vertical guidance but not meeting precision approach standards, or a non-precision approach procedure (NPA) using lateral guidance only.
Plain English
An ICAO instrument approach procedure is a step-by-step published path a pilot flies using cockpit instruments to safely descend from cruise altitude down to a point where they can either land or break off and try again. ICAO sorts these procedures into three types based on whether the procedure provides full guidance up and down (precision), partial vertical help (with vertical guidance), or only side-to-side guidance (non-precision).
Context Anchor
Seen on instrument approach charts, in instrument flight training, and in clearances for landing when weather or visibility requires instrument guidance.
Derivation
ICAO stands for International Civil Aviation Organization, the United Nations body that sets worldwide aviation standards. The [ICAO] tag means this definition reflects the international standard, which can differ slightly from the FAA's domestic version of the same term.
Why Pilots Care
Provides a standardized, safe method to reach the runway when visibility is too low for visual approaches.
Intuition Check
Do not read approach as just flying generally toward an airport. Here, it means a published, protected path with specific points, altitudes, and actions. [ICAO] means this wording follows International Civil Aviation Organization usage, not a separate maneuver.
Example Sentence 1
Before flying into the airport in Europe, the captain briefed the ICAO instrument approach procedure, noting it was classified as APV with vertical guidance from the satellite-based system.
Example Sentence 2
ATC cleared the flight to fly the published Instrument Approach Procedure [ICAO] for the runway in use.