Which inputs does TCAS II primarily rely on to determine resolution advisories?

Which inputs does TCAS II primarily rely on to determine resolution advisories?

• A. Relative altitude and range to other aircraft.
• B. Ground elevation and weather radar tilt.
• C. Aircraft speed alone.
• D. Pilot voice reports.

Answer: (A)

TCAS II determines resolution advisories from the three‑dimensional position information of nearby aircraft, which mainly comes from the other aircraft’s transponder replies. The crucial inputs are how far away another airplane is (range) and how high or low it is relative to you (relative altitude). With this geometry, TCAS II can assess whether you and the intruder are on a collision course and decide if a vertical maneuver is needed to maintain safe separation. Ground elevation and weather radar tilt aren’t used to generate RAs, and speed alone or pilot voice reports don’t provide the necessary position data for automatic resolution advisories.

TCAS II determines resolution advisories from the three‑dimensional position information of nearby aircraft, which mainly comes from the other aircraft’s transponder replies. The crucial inputs are how far away another airplane is (range) and how high or low it is relative to you (relative altitude). With this geometry, TCAS II can assess whether you and the intruder are on a collision course and decide if a vertical maneuver is needed to maintain safe separation. Ground elevation and weather radar tilt aren’t used to generate RAs, and speed alone or pilot voice reports don’t provide the necessary position data for automatic resolution advisories.