Definition
The ARTCC (Air Route Traffic Control Center) facility that has jurisdiction over the airspace above a given Terminal Radar Approach Control (TRACON) or tower facility. When a flight departs the lower terminal-area airspace, control is handed off upward to the overlying Center, which manages en route traffic at higher altitudes.
Plain English
The big regional control facility that handles the airspace sitting on top of a local approach or tower's airspace. Once you climb out of the local controller's area, you're talking to the Center above them.
Context Anchor
Seen in air traffic control discussions, especially when describing which facility controls aircraft above a local approach control area.
Derivation
Overlying' simply means 'lying on top of.' Airspace is layered vertically — terminal airspace below, en route airspace above — so the Center 'overlies' the terminal facility beneath it.
Why Pilots Care
Pilots need to know the overlying center to make the correct frequency change and receive proper routing and separation once above the terminal airspace.
Intuition Check
Do not read “Center” as the middle point of an area. Here it means a regional FAA air traffic control facility. “Overlying” also means responsible for the airspace above another facility’s area, not just physically located overhead.
Example Sentence 1
After departure, the tower handed us off to the overlying Center for our climb to cruise altitude.
Example Sentence 2
The overlying center issued a direct routing once the flight was clear of the terminal area.