Definition
An instrument approach procedure that provides the pilot with electronic guidance in both the lateral (left/right) and vertical (up/down) dimensions, meeting ICAO Annex 10 standards. Examples include the Instrument Landing System (ILS), Precision Approach Radar (PAR), and the Ground-Based Augmentation System (GBAS) Landing System (GLS).
Plain English
A type of instrument approach where the aircraft's navigation equipment guides the pilot both side-to-side onto the runway centerline and down a precise descent path to the runway.
Context Anchor
Seen in instrument procedure discussions, approach charts, and final approach segment descriptions.
Derivation
‘Precision’ comes from Latin praecisio, meaning ‘a cutting off’ or ‘exactness.’ In this context it refers to the exact, narrow tolerances of the guidance signal — both horizontally and vertically — rather than meaning ‘perfect.’
Why Pilots Care
Allows safe descent to lower altitudes and minimums in reduced visibility than non-precision approaches permit.
Grounding Statement
On a precision approach, the pilot is not just aiming toward the runway; the procedure also shows whether the airplane is too high, too low, left, or right on final.
Intuition Check
Precision approach does not just mean a careful or well-flown approach. In FAA use, it means a specific type of published instrument approach that provides approved alignment and descent-path guidance.
Example Sentence 1
With the ceiling reported at 300 feet, the crew elected to fly the ILS as a precision approach into Runway 27.
Example Sentence 2
When weather dropped below non-precision minimums, the pilot requested the PA instead.