Definition
The provision of advice and information to a pilot based on radar observations, issued by an air traffic controller. The information typically includes traffic, weather, terrain, or other observed factors, but the pilot remains responsible for separation and the safe conduct of the flight.
Plain English
A controller watching a radar screen tells the pilot what they see — like nearby traffic or weather — but does not take over flying decisions. The pilot is still in charge of staying clear of other aircraft and obstacles.
Context Anchor
Used during radio communication with air traffic control when a controller is watching your aircraft or nearby conditions on radar.
Derivation
Radar comes from “radio detection and ranging,” meaning using radio waves to detect objects and measure how far away they are. Advisory comes from “advise,” meaning to give helpful information or guidance. Together, the term means guidance based on radar observations.
Why Pilots Care
It improves situational awareness of traffic and weather when the pilot is not under full ATC navigation guidance.
Intuition Check
Do not read “advisory” as a clearance or command. A radar advisory is information from the controller; it does not remove the pilot’s responsibility for safe flight.
Example Sentence 1
Approach issued a radar advisory about VFR traffic crossing two miles ahead at the same altitude, so the pilot adjusted course to pass behind it.
Example Sentence 2
While on flight following the pilot received a radar advisory about a line of thunderstorms twenty miles ahead.