Traffic Collision Avoidance System (TCAS)
The Traffic Collision Avoidance System (TCAS) is an onboard safety tool in aviation that helps prevent mid-air collisions. It detects nearby aircraft with transponders, providing pilots with traffic advisories (TAs) and, if necessary, resolution advisories (RAs) that suggest specific maneuvers to avoid collisions. TCAS operates independently from air traffic control and has different versions—TCAS I provides alerts without maneuvers, while TCAS II (used in larger aircraft) offers both alerts and vertical avoidance commands. Although it’s highly effective, TCAS only detects transponder-equipped aircraft and is meant as a supplement, not a replacement, for air traffic control.
