Definition
An instrument approach in which a controller uses radar to provide navigational guidance, by voice radio, to an aircraft on final approach to a runway. The two types are the Precision Approach Radar (PAR), which provides azimuth and glidepath guidance, and the Airport Surveillance Radar (ASR), which provides azimuth guidance only.
Plain English
A landing approach where a controller watches the aircraft on radar and tells the pilot, over the radio, exactly which way to turn and (sometimes) when to climb or descend, all the way down toward the runway.
Context Anchor
Seen in instrument flying and air traffic control procedures, especially when a controller is providing approach guidance instead of the pilot following a normal cockpit navigation display.
Derivation
Radar comes from Radio Detection and Ranging, a system that bounces radio waves off objects to measure their position and distance. A radar approach is simply an approach guided by that radar picture rather than by signals the aircraft receives directly through its own navigation instruments.
Why Pilots Care
Allows a safe arrival at the runway when visibility is too low for a visual approach and no other instrument landing system is in use.
Intuition Check
Do not read “radar approach” as any landing approach where radar happens to be in use. In this term, it means a specific controller-guided instrument approach based on radar tracking.
Example Sentence 1
After the GPS failed in cloud, the pilot requested a radar approach and the controller began issuing headings and descent instructions.
Example Sentence 2
During training the instructor requested a radar approach so the student could practice following heading and altitude instructions from ATC.