Definition
In Tower En Route Control (TEC), city pairs are pre-coordinated departure-and-arrival airport combinations between which IFR flights can be conducted entirely within terminal (approach control) airspace, without entering the en route ATC system. Each TEC route is published as a specific city pair with an associated route, altitude, and aircraft category.
Plain English
A city pair is just two airports listed together as a recognized start-and-finish for a short IFR trip. ATC has already worked out a route between them, so you can fly from one to the other under IFR while staying with approach controllers the whole way.
Context Anchor
Seen in Tower En Route Control discussions or route listings when checking whether a planned instrument flight can use a published tower en route route.
Why Pilots Care
Pilots receive faster clearances and can often fly at lower altitudes without filing a complete route.
Grounding Statement
The important point is that the route is approved for a specific departure-and-destination pairing, not automatically for every airport near those cities.
Intuition Check
Do not read city pairs as simply “two cities.” In this context, it means an approved departure-and-destination combination used for a specific published route.
Example Sentence 1
Before filing, the pilot checked the TEC route listing to confirm that Long Beach to Palomar was a published city pair.
Example Sentence 2
Controllers routinely assign altitudes below 10,000 feet for city pairs in the Northeast corridor.