Definition
A ground-based radar system used by air traffic controllers to guide an aircraft down a final approach to a runway by providing precise position information in three dimensions: azimuth (left/right of the runway centerline), elevation (above/below the glide path), and range (distance from touchdown). The controller monitors the aircraft on the radar display and issues continuous voice instructions for heading and descent corrections until the aircraft reaches decision height or the runway is in sight.
Plain English
A type of radar at the airport that lets a controller watch exactly where you are on final approach and talk you down to the runway, telling you how to steer and when to adjust your descent.
Context Anchor
Seen in instrument approach procedures and air traffic control services, especially at airports equipped to provide radar-guided approaches.
Derivation
Precision means accurate to a fine degree. Approach refers to the final segment of flight before landing. Radar comes from RAdio Detection And Ranging — using radio signals to find an object's position and distance. Together, the name describes a radar system accurate enough to guide an aircraft along the precise path needed for landing.
Why Pilots Care
Provides a safe landing option in low visibility when other precision aids are unavailable or during controller training.
Intuition Check
PAR is not radar equipment the pilot uses in the cockpit. It is a ground-based air traffic control service that gives the pilot spoken guidance.
Example Sentence 1
With the ILS out of service, the controller offered us a PAR approach to runway 27 and talked us down to minimums.
Example Sentence 2
During the PAR approach the pilot responded to each instruction while keeping the aircraft aligned with the runway centerline.