Definition
A runway served by an instrument approach procedure that provides lateral guidance (course alignment to the runway) but no electronic vertical guidance to the touchdown point. Pilots descend using published step-down altitudes and a Minimum Descent Altitude (MDA) rather than following an electronic glidepath.
Plain English
A runway you can fly to in cloud or low visibility using instruments that tell you where the runway is left-and-right, but not how high you should be at each point. You manage the descent yourself, level off at a published minimum altitude, and look for the runway from there.
Context Anchor
Seen in airport runway descriptions, instrument approach planning, and FAA runway classification discussions.
Derivation
"Nonprecision" here does not mean sloppy or inaccurate. It is a regulatory category: an approach without electronic vertical (glideslope) guidance is classified as nonprecision, regardless of how accurate the lateral guidance is.
Why Pilots Care
The classification sets the landing minimums, including decision altitude or height and required visibility, and determines whether a straight-in landing is authorized.
Intuition Check
Do not read “nonprecision” as “inaccurate” or “unsafe.” Here it means the approach gives runway alignment guidance, but not an approved glidepath down to the runway.
Example Sentence 1
Runway 27 is a nonprecision approach runway, so we'll fly the localizer course down to the MDA and look for the runway environment before going missed.
Example Sentence 2
Runway 18 is designated a nonprecision approach runway, so circling minimums apply if the pilot cannot land straight in.