Definition
Instrument approach procedures that provide lateral (left/right) course guidance to a runway or airport, but do not provide electronic vertical (glidepath) guidance. The pilot must manage the descent using published step-down altitudes and a minimum descent altitude (MDA).
Plain English
An instrument approach where the equipment tells you whether you are lined up with the runway, but does not tell you whether you are at the right height. You handle the descent yourself using altitudes printed on the approach chart.
Context Anchor
Seen when using traditional navigation systems, such as an ADF, to fly an approach in clouds or low visibility.
Derivation
Non- (not) + precision. In approach terminology, 'precision' specifically refers to having electronic vertical guidance. So 'nonprecision' means 'no vertical guidance' — not 'imprecise' or 'inaccurate.'
Why Pilots Care
These approaches have higher minimum altitudes and visibility requirements, directly affecting the decision to land or go around.
Intuition Check
Do not read “nonprecision” as “careless” or “less accurate flying.” It means the approach lacks approved vertical glidepath guidance, so the pilot has to control the descent using the published procedure.
Example Sentence 1
Because the airport only had a VOR approach, the crew briefed it as a nonprecision instrument approach and reviewed the step-down altitudes carefully.
Example Sentence 2
Nonprecision approaches require the pilot to reach the missed approach point at the MDA before deciding whether to land.