Definition
The dedicated communications network used by the FAA to exchange air traffic control data and voice messages between air traffic facilities, including towers, TRACONs, and Air Route Traffic Control Centers. It is the backbone that lets controllers coordinate handoffs, flight plans, and traffic information across facility boundaries.
Plain English
It is the FAA's internal phone and data network that lets air traffic facilities talk to each other behind the scenes, so traffic can be passed smoothly from one controller to the next.
Context Anchor
Seen in FAA acronym lists and in discussions of how aviation information moves between FAA facilities, rather than as equipment a pilot normally operates directly.
Derivation
"Interfacility" means "between facilities." The name simply describes what it is: a nationwide system for communication between (inter-) ATC facilities.
Why Pilots Care
Smooth handoffs between controllers, accurate flight plan transfers, and timely traffic coordination all depend on this system. When it works, the pilot rarely notices; when it fails, delays and miscommunications can follow.
Intuition Check
Do not read NICS as a cockpit radio system for pilots. It is mainly a facility-to-facility communication system used behind the scenes.
Example Sentence 1
Coordination between the tower and the en route center is carried over the National Interfacility Communications System.
Example Sentence 2
NICS links centers so traffic information moves quickly between sectors.