Definition
An FAA facility that provides air traffic control services to aircraft operating on IFR flight plans within controlled airspace, primarily during the en route phase of flight between departure and destination terminal areas. Each Center is responsible for a large geographic block of airspace, and the United States is divided into 21 such Centers covering the contiguous airspace of the country.
Plain English
A regional air traffic control facility that handles aircraft once they have climbed away from the airport area and are cruising between cities. Controllers there watch and direct aircraft across a large slice of the country until they hand them off to the next Center or to the destination airport's controllers.
Context Anchor
You encounter this term in air traffic control, radio communication, instrument flight, and cross-country flight planning. In flight, a pilot is often handed off from departure control to a Center, and later from a Center to approach control.
Derivation
The name describes the function: a 'center' (central facility) that controls 'air route' traffic — the traffic flying along the airway routes between airports. It is commonly shortened to ARTCC, or simply called 'Center' on the radio (e.g., 'Denver Center').
Why Pilots Care
These centers maintain safe separation between aircraft and issue routing instructions that keep flights on course and out of conflict.
Intuition Check
Do not read “center” as the middle of something. In this term, “Center” means a regional air traffic control facility responsible for aircraft moving through a large area.
Example Sentence 1
After departure, the tower handed us off to Denver Center, which controlled our flight across most of Colorado.
Example Sentence 2
After takeoff the aircraft was handed off to the next Air Route Traffic Control Center for the remainder of the flight.