Definition
An air traffic control service provided by an Air Route Traffic Control Center (ARTCC) that handles approach and departure functions for IFR aircraft operating to or from airports located in areas where a separate approach control facility has not been established. The center controller sequences arrivals onto an instrument approach and provides separation and routing for departing IFR aircraft until they are released to en route control or to the destination tower.
Plain English
When an airport is too remote or too quiet to need its own approach control office, the regional center handles those duties instead. The same controllers who manage high-altitude traffic also bring IFR aircraft down to the airport and send IFR departures on their way.
Context Anchor
You may see this in instrument training, airport information, or assigned frequencies when flying to or from an airport served by Center rather than by a local approach control facility.
Derivation
Center' here refers to an Air Route Traffic Control Center (ARTCC), the FAA facility responsible for IFR traffic between terminal areas. When that same facility also performs the approach and departure role, the combined service is called Center Approach/Departure Control.
Why Pilots Care
Knowing the provider is Center rather than a local facility lets the pilot use the correct frequency, expect appropriate separation services, and anticipate the handoff sequence during the transition from enroute to terminal airspace.
Intuition Check
“Center” does not mean the middle of the airport or runway. Here it means the regional air traffic control facility that can handle arrivals and departures for airports in its area.
Example Sentence 1
Departing IFR from a small rural airport, the pilot was told to contact Center Approach/Departure Control after takeoff for radar vectors on course.
Example Sentence 2
After takeoff Center Approach/Departure Control issued a climb to 6000 feet and later handed the flight off to the next sector.