Definition
A primary radar system used to assist a pilot during the final approach to landing. It provides the controller with high-accuracy information on the aircraft's position relative to the extended runway centerline (azimuth), the correct glide path (elevation), and the distance from the runway threshold (range). The controller uses this data to give the pilot continuous talk-down instructions until the aircraft reaches a point where a visual landing can be completed.
Plain English
A specialized ground radar that watches an aircraft very closely as it approaches the runway. The controller can see exactly where the aircraft is — left or right of centerline, above or below the correct descent path, and how far from the runway — and reads instructions to the pilot to keep it on track until landing.
Context Anchor
You may see this term in instrument approach, air traffic control, and airport facility information, especially at locations that provide controller-guided radar approaches.
Derivation
‘Precision’ comes from Latin praecisio, meaning ‘a cutting short’ or ‘exactness.’ ‘Approach’ here means the final segment of flight toward landing. The name highlights that this radar gives precise — not just general — guidance during the most critical phase of flight.
Why Pilots Care
Enables safe landings in weather conditions where visual references are insufficient, expanding the range of usable airports and reducing weather-related delays or diversions.
Grounding Statement
Picture the aircraft on short final with the controller watching its path on radar and calling corrections such as slightly left, slightly right, above path, or below path.
Intuition Check
Do not read “precision” as just “very accurate radar.” Here it means radar accurate enough to support controller-provided guidance for both runway alignment and descent path on final approach.
Example Sentence 1
After losing the glideslope receiver, the crew requested a PAR approach and followed the controller's headings and descent calls down to minimums.
Example Sentence 2
During training the student pilot flew a low-visibility approach guided by Precision Approach Radar instructions from the controller.