Definition
Under ICAO definitions, a runway intended for the operation of aircraft using instrument approach procedures. ICAO classifies instrument runways into three types: a) Non-precision Approach Runway — an instrument runway served by visual aids and a non-visual aid providing at least directional guidance adequate for a straight-in approach; b) Precision Approach Runway, Category I — an instrument runway served by ILS and visual aids intended for operations down to a 200-foot decision height and a runway visual range of not less than 800 meters; c) Precision Approach Runway, Categories II and III — an instrument runway served by ILS to and along the surface of the runway and intended for operations down to and along the surface of the runway with progressively lower decision heights and runway visual ranges.
Plain English
A runway built and equipped for aircraft arriving by instrument approach rather than by sight alone. ICAO sorts these runways into three categories based on how much guidance the equipment provides and how low pilots can descend in poor visibility before needing to see the runway.
Context Anchor
Seen in airport information, approach procedure discussions, and runway capability descriptions, especially when weather may reduce what the pilot can see outside.
Derivation
‘Instrument’ here points to instrument flight — flying by reference to cockpit instruments rather than outside visual cues. The label tells you the runway is set up to support that kind of arrival, with the navigation aids needed to bring an aircraft down through cloud or low visibility.
Why Pilots Care
Allows safe operations in low visibility or instrument meteorological conditions, reducing accident risk during precision and non-precision approaches.
Grounding Statement
If the pilot cannot count on seeing the runway early, an instrument runway is the kind of runway meant to be approached using approved instrument guidance.
Intuition Check
“Instrument” does not mean the runway itself has cockpit instruments. It means the runway is intended to be used with an aircraft’s instruments and published approach guidance.
Example Sentence 1
The destination airport had a Category II precision approach runway, which allowed the crew to plan for a lower decision height than a standard Cat I arrival.
Example Sentence 2
Due to fog, the tower closed the visual runway and directed all arrivals to the instrument runway on the opposite end of the field.