Definition
An air traffic control facility that uses radar to provide separation, sequencing, and approach services to aircraft arriving at, departing from, or transiting the airspace surrounding one or more busy airports, typically from the surface up to about 10,000 feet and out to roughly 30 to 50 nautical miles from the primary airport. A TRACON hands aircraft off to the airport tower for landing and to the en route center (ARTCC) for higher-altitude cruise.
Plain English
A radar facility staffed by controllers who guide aircraft through the busy airspace around an airport, lining them up for approach or sending them on their way after departure. They sit between the airport tower and the long-range center controllers.
Context Anchor
You encounter TRACON during radio handoffs near busy airports, especially on instrument flights, departures, arrivals, and radar approaches.
Derivation
Terminal refers to the airspace at the ends of a flight -- arrival and departure -- as opposed to the en route portion in the middle. Radar Approach Control describes what the facility does: uses radar to control aircraft on approach (and departure). The name is descriptive of its job and its location in the flight.
Why Pilots Care
Ensures orderly flow of arriving and departing traffic to prevent conflicts.
Intuition Check
Do not read “terminal” as the airport passenger building. Here it means the airport-area airspace. Do not read “approach” as only the final moments before landing. TRACON can also handle departures and aircraft passing through the area.
Example Sentence 1
After takeoff from Phoenix, the tower handed us off to TRACON, who vectored us around traffic before clearing us on course.
Example Sentence 2
TRACON controllers manage traffic within a 30-mile radius of the airport.