The TCAS resolution advisory requires what action and reporting to ATC after resolution?

• A. inform ATC immediately and proceed as RA suggests
• B. take resolution advisory action immediately and once conflict is resolved, return to the last ATC
• C. take resolution advisory action immediately and remain at the new altitude; inform ATC as soon as possible
• D. do not change altitude until ATC clearance

Answer: (B)

The aspect being tested is how to handle a TCAS resolution advisory and subsequent ATC communication. When TCAS issues a resolution advisory, you must act immediately to change altitude to resolve the threat; this maneuver takes priority over ATC instructions. After the conflict is resolved, you should return to the altitude last assigned by ATC (the previously assigned altitude) and you should inform ATC as soon as practical about the resolution so they’re aware of the updated traffic situation.

This is why the best choice is to take RA action right away and, once the conflict is cleared, revert to the last altitude assigned by ATC. The other options imply maintaining the new altitude, waiting for clearance, or starting actions without reverting back to ATC guidance, which would violate the required priority of RA and proper ATC coordination.