Definition
A ground-based air traffic surveillance service that uses radar data to send nearby traffic information directly to suitably equipped aircraft via a Mode S data link. The information appears on a cockpit display and shows the position, altitude, and movement of other transponder-equipped aircraft within a defined range, helping the pilot maintain visual separation.
Plain English
A service that uses ground radar to send a picture of nearby aircraft up to your cockpit so you can see where other traffic is and avoid it.
Context Anchor
Seen in avionics manuals, traffic display descriptions, and discussions of electronic traffic awareness in radar-covered areas.
Why Pilots Care
Gives pilots early awareness of nearby traffic so they can spot and avoid other aircraft before a conflict develops.
Intuition Check
Do not read “service” as a guarantee that all traffic is being watched for you. Traffic Information Service is advisory only; it helps awareness but does not replace the pilot’s responsibility to see and avoid other aircraft.
Example Sentence 1
With TIS active on the Mode S transponder, the pilot saw a target two miles ahead and 500 feet below before spotting it visually.
Example Sentence 2
While on approach in marginal weather, the Traffic Information Service helped locate a slower aircraft on the same route.