Plain English Meaning

Equipment in the cockpit that watches for other aircraft nearby and tells the pilot when one is getting too close, with a screen showing where the traffic is and a voice or chime that warns when action may be needed.

Full Definition

Onboard avionics that monitor the airspace around an aircraft for other transponder-equipped aircraft and warn the pilot when another aircraft is close enough to be a collision risk. The two main families are TCAS (Traffic Alert and Collision Avoidance System), found primarily on transport-category aircraft, and TAS/TIS (Traffic Advisory System / Traffic Information Service), commonly installed in general aviation aircraft. These systems nearby traffic on a cockpit screen and issue audible and alerts as the increases.