TCAS uses transponder interrogation and return signals to determine if aircraft around you pose a threat. In order to detect these aircraft, they must be equipped with an operating Mode A, C, or S transponder. Note: Mode A transponders will provide range and bearing only - no altitude info.
TCAS I provides TAs only.
TCAS II provides TAs and RAs.
Some notes:
- Traffic Advisories (TAs) and Resolution Advisories (RAs) are only provided in the vertical plane (azimuth information is not reliably accurate)
- pilots should only alter their flight in the event of a RA (not a TA).
- notify ATC ASAP of any deviation from your clearance. Also notify them when you are clear of the conflict and returning to the cleared altitude
- See also CAR 602.31 (3) and (4) Compliance with ATC instructions and clearances
AIM RAC 12.16.6 (a) "Although TCAS will never be a complete substitute for a good lookout, good situational awareness and proper radio procedures, it has been proven to be a valuable tool in providing information on potential collision hazards."
