Definition
A radar-based approach in which a ground controller uses precision or surveillance radar to give the pilot continuous instructions for heading, and in some cases altitude, to guide the aircraft to a runway. A precision approach (PAR) provides azimuth, range, and glidepath information; a surveillance approach (ASR) provides azimuth and range only. The pilot flies the aircraft based on the controller's verbal instructions rather than on cockpit navigation instruments.
Plain English
A landing approach where a controller on the ground watches the aircraft on radar and tells the pilot which way to turn, and sometimes when to climb or descend, to line up with the runway. The pilot flies what the controller says, step by step, all the way down.
Context Anchor
Used during instrument approaches, especially when a pilot is relying on air traffic control radar guidance to reach the runway in poor visibility or for practice.
Derivation
The name describes the procedure plainly: the approach is controlled from the ground rather than flown using onboard navigation. It dates from World War II, when ground radar operators first began talking pilots down through poor weather.
Why Pilots Care
Enables a safe landing when weather is below visual or other instrument approach minimums and no other guidance is usable.
Intuition Check
Do not read “controlled” as meaning the controller flies the aircraft. In a Ground Controlled Approach, the controller gives spoken guidance, and the pilot remains responsible for flying the airplane.
Example Sentence 1
After losing both navigation receivers in the clouds, the pilot requested a ground controlled approach into the nearest military field.
Example Sentence 2
Throughout the ground controlled approach the controller issued small heading corrections to keep the aircraft aligned with the runway centerline.