Definition
A pre-coded routing stored in the air traffic control computer system that connects a specific departure airport directly to a specific arrival airport. When a flight plan matches the city pair, the system automatically inserts the full route — from departure fix through en route segments to arrival fix — without the controller or pilot having to build it manually.
Plain English
A ready-made route the ATC computer keeps on file for common airport-to-airport trips. If your flight plan matches one of these airport pairs, the computer fills in the whole route for you.
Context Anchor
Seen in FAA glossary and ATC route-planning discussions. A pilot may notice its effect when an instrument clearance gives a specific path for departure or arrival instead of a simple direct route.
Derivation
"Adapted" here means "customized for the local facility." Each ATC facility adapts its computer to handle the traffic flows it actually sees, so an ADAR is a route that has been pre-built and stored to match a common departure-to-arrival pairing at that facility.
Why Pilots Care
Pilots may be directed to fly an ADAR rather than a standard procedure, which can affect their route, altitude, and compliance with local noise rules.
Intuition Check
“Adapted” does not mean the route is being improvised in the moment. Here it means the route has been built into ATC’s computer data for use in that area.
Example Sentence 1
Because an ADAR existed for the city pair, the controller cleared the flight on the adapted route rather than the one originally filed.
Example Sentence 2
Preflight briefing included review of the ADAR for the destination airport due to noise abatement requirements.