TCAS (Traffic Collision Avoidance System)
Definition
An aircraft system that monitors nearby aircraft transponder signals and provides resolution advisories (climb/descend) to prevent mid-air collisions, independent of air traffic control.
Related Terms
Transponder
An electronic device on an aircraft that receives radar signals and automatically transmits a response with identification and altitude information back to air traffic control.
Separation Standards
Minimum distances or time intervals required between aircraft to ensure safety. Vertical separation is typically 1,000 feet; horizontal separation varies by radar coverage and airspace type.
GPWS/EGPWS (Ground Proximity Warning System)
An aircraft system that alerts pilots when they are in danger of flying into terrain. The enhanced version (EGPWS) uses a terrain database to provide earlier, more accurate warnings.