Definition
An Air Route Traffic Control Center (ARTCC) is an FAA facility that provides air traffic control service to aircraft operating on IFR flight plans within controlled airspace, principally during the en route phase of flight. Pilots address the facility on the radio simply as 'Center,' prefixed by the geographic name of the specific ARTCC (for example, 'Denver Center' or 'Jacksonville Center').
Plain English
Center is the controller you talk to when you're flying high and far between airports. They watch you on radar across large regions of the country and hand you off from one Center to the next as you cross the country.
Context Anchor
Heard on the radio with names such as “Denver Center,” “Atlanta Center,” or “Oakland Center,” and seen in flight planning and air traffic control discussions.
Derivation
The word 'center' here points to the physical facility — a single building housing the controllers and radar equipment that oversees a large block of airspace. Each ARTCC is the central hub for traffic flowing through its region, hence the name.
Why Pilots Care
Center provides traffic separation, routing, and weather advisories during the cruise portion of an IFR flight.
Intuition Check
Do not read “Center” as simply “the middle.” In this FAA context, Center means a specific type of air traffic control facility.
Example Sentence 1
After departure, Tower handed us off to Approach, and once we leveled at cruise altitude, Approach passed us to Denver Center.