What does TCAS stand for?

• A. Traffic Collision Avoidance System
• B. Traffic Congestion Alert System
• C. Terrain Clearance Advisory System
• D. Tactical Collision and Surveillance System

Answer: (A)

TCAS stands for Traffic Collision Avoidance System. In flight, this onboard system monitors nearby traffic by exchanging transponder signals and calculating relative positions and movement. When a potential collision is detected, TCAS provides traffic advisories to help you locate the other aircraft, and can issue resolution advisories that suggest maneuvers like climbs or descents to maintain safe separation. The other options don’t fit because they describe systems or purposes that aren’t what TCAS does: congestion alerts aren’t the function of TCAS, terrain clearance relates to terrain awareness systems, and a tactical collision and surveillance term isn’t used in this context.