AIM Text
Centers are established primarily to provide air traffic service to aircraft operating on IFR flight plans within controlled airspace, and principally during the en route phase of flight.
Source: FAA Aeronautical Information Manual · current edition · paragraph 4-1-1.
The short answer
This AIM section is FAA advisory guidance explaining that Air Route Traffic Control Centers (Centers) are established primarily to provide air traffic service to aircraft operating on IFR flight plans within controlled airspace, and principally during the en route phase of flight.
Research Notes
Common Questions
What is an Air Route Traffic Control Center (ARTCC)?
Per this AIM section, Centers are established primarily to provide air traffic service to aircraft operating on IFR flight plans within controlled airspace.
During what phase of flight do Centers primarily provide service?
The AIM states Centers principally provide service during the en route phase of flight, as distinguished from terminal-area control handled by towers.
Do Centers serve VFR or IFR traffic?
According to the AIM, Centers are established primarily to serve aircraft operating on IFR flight plans within controlled airspace; their core role is IFR en route air traffic service.