Definition
Runways equipped to support instrument approaches that provide both lateral (left/right) and vertical (glidepath) electronic guidance to the pilot, allowing landings in low visibility. They are served by an Instrument Landing System (ILS) or equivalent, and are marked and lit to specific standards including touchdown zone lighting and centerline lighting.
Plain English
A runway built and equipped for landings when the weather is poor, using radio signals that guide the airplane both side-to-side and up-and-down all the way to the runway.
Context Anchor
Seen in airport lighting, runway marking, and instrument approach discussions, especially when learning why some runways have extra lighting built into or near the runway surface.
Derivation
‘Precision’ comes from the Latin praecisio, meaning ‘a cutting off’ or ‘exactness.’ In this context it refers to the exactness of the guidance provided — not just where the runway is, but exactly how high the aircraft should be at every point along the approach.
Why Pilots Care
Identifies which runways provide the visual and electronic cues needed for low-visibility landings and determines applicable minimums.
Intuition Check
Precision does not mean the runway itself is more perfectly built. It means the approach to that runway gives the pilot more exact guidance, including both alignment and descent path.
Example Sentence 1
Because the destination has a precision approach runway, the flight could continue even with a low cloud ceiling forecast.
Example Sentence 2
Charts mark precision approach runways with specific lighting symbols so pilots know what visual aids will be available.