How does TCAS function on the A320 and what actions should you take on a Resolution Advisory (RA)?

• A. TCAS detects intruders and provides RA; follow ATC instructions and RA procedures to maintain safe separation.
• B. Ignore the RA and rely solely on ATC vectors.
• C. TCAS provides only advisory information; no action is required.
• D. Turn off TCAS to avoid conflicting instructions.

Answer: (A)

TCAS on the A320 actively watches the airspace around you by using nearby transponder signals to detect potential conflicts. It can warn you with a Traffic Advisory to alert you to traffic in your vicinity, and if the threat persists, it issues a Resolution Advisory that prescribes a vertical maneuver to restore safe separation. The important point is that when a Resolution Advisory is displayed, you must promptly execute the maneuver it specifies—climb or descend—so you increase the distance from the intruder as directed. This action takes priority over other considerations, including ATC instructions, because the RA is designed to prevent collision and buy you time to maintain safe separation. Continue to follow the RA until TCAS cancels it, then resume your normal ATC clearance and traffic awareness. Never switch TCAS off, and never ignore an RA; if ATC guidance would conflict with the RA, you should still comply with the RA and coordinate with ATC as soon as possible after the maneuver is established.