Definition
An instrument approach procedure that provides lateral (course) guidance to the runway but does not provide vertical (glide path) guidance certified to precision-approach standards. Examples include VOR, NDB, LOC (localizer only), and LNAV-only RNAV approaches. Pilots descend in steps to published minimum altitudes until reaching the Minimum Descent Altitude (MDA), which they may not descend below unless the required visual references and other regulatory conditions are met.
Plain English
An instrument approach that tells you which way to fly toward the runway but does not give you an electronic slope to follow down. You step down through published altitudes until you reach a minimum altitude, and you can only go lower if you can see the runway environment.
Context Anchor
Seen on instrument approach charts and in instrument flying, especially when planning or flying the final approach segment.
Derivation
"Non-precision" simply means "not precision." A precision approach (like an ILS) provides certified vertical guidance with tight tolerances. Removing that vertical guidance — or providing it without meeting precision standards — makes the approach "non-precision."
Why Pilots Care
Determines the minimum descent altitude, required equipment, and pilot decision-making during low-visibility arrivals.
Intuition Check
Non-precision does not mean careless, rough, or unsafe. It means the approach lacks approved vertical guidance, so the pilot must manage the descent using the published altitude limits.
Example Sentence 1
With the ILS out of service, we briefed the LOC approach as a non-precision approach and planned our step-down altitudes to the MDA.
Example Sentence 2
Because it was an NPA, the crew planned a higher decision altitude than they would have used on the ILS.