resolution advisory

Resolution advisories provide pilots with information to change a flight path or to prevent a manoeuvre that could cause insufficient separation between aeroplanes.

TCAS will issue traffic advisories (TA) and resolution advisories (RA), when appropriate.

(2) TCAS II provides both TAs and recommended vertical escape manoeuvres (resolution advisories or RAs).

ATC can be automatically informed about resolution advisories issued by TCAS only when the aircraft is within an area covered by a Mode S, or an ADS-B monitoring network.