Does TCAS overrule ATC?
TCAS Overrides Human Decision Even if ATC gives instructions, RA takes priority. TCAS works in a coordinated manner, so when an RA is issued to conflicting aircraft, a required action (i. Climb. Climb. RA in the opposite direction (i. Descend. Descend.
Can aircraft fly without TCAS?
Naturally, aircraft operating without operational TCAS II or in TA-only mode will have limited or no protection, depending on the equipage of the intruder aircraft. TCAS II equipped aircraft will only provide protection against threats with altitude reporting transponders. TCAS is programmed to stop giving alerts in certain conditions automatically. RAs are inhibited when the aircraft is less than 1,000 feet above the ground. This prevents dangerous maneuvers during takeoff and landing.