Definition
A Terminal Radar Service Area (TRSA) is an area surrounding certain airports where radar service is provided to participating IFR and VFR aircraft. Within a TRSA, controllers offer sequencing, separation between IFR aircraft, and separation between participating VFR and IFR aircraft. Pilot participation is voluntary for VFR aircraft, but encouraged. TRSAs are depicted on VFR sectional charts with a solid black line and altitudes shown in black numbers.
Plain English
An area of airspace around some airports where air traffic control uses radar to help keep aircraft safely spaced and orderly as they arrive and depart. VFR pilots aren't required to use the service, but they're encouraged to.
Context Anchor
Seen on aeronautical charts and in airport-area planning when approaching, departing, or passing near an airport with this radar service.
Derivation
Terminal' here means the area near an airport where flights begin or end (from Latin terminus, meaning end or boundary). So a Terminal Radar Service Area is simply a radar-supported service zone around an airport terminal area.
Why Pilots Care
VFR pilots can receive helpful radar guidance and traffic calls inside this airspace without having to file a flight plan or follow mandatory procedures.
Grounding Statement
Picture the airspace around a busy airport as a radar-watched traffic area where controllers help aircraft line up, depart, arrive, and pass through without getting too close to each other.
Intuition Check
Terminal does not mean the airport passenger building here. It means the airspace near an airport where flights are arriving, departing, or transitioning through the airport area.
Example Sentence 1
Approaching the airport, the pilot contacted approach control and requested TRSA service for sequencing into the pattern.
Example Sentence 2
Participation is voluntary for VFR aircraft inside the Terminal Radar Service Area, unlike Class B airspace.