TCAS
TCAS - Traffic Collision Avoidance System
Gliders are not TCAS equipped although FLARM is similar in concept.
What is TCAS?
See page 3-4 of this document for more information.
Who is TCAS equipped?
All airliners, most corporate jets and some turboprops.
"RA" Resolution Advisory
The target (red square) is 25 seconds from closest point of approach.
This target aircraft is 200 feet higher than the viewer and descending by at least 500 feet/minute.
The TCAS equipped aircraft will receive an RA (Resolution Advisory) that tells (quite loudly) them to either climb or descend.
Typical TCAS Display
"TA" Traffic Advisory
Target aircraft is 40 seconds from closest point of approach.
The target aircraft is level with the viewer and is climbing or descending less than 500 feet/minute.
The viewer will receive a TA (Traffic Advisory) that has a audio "Traffic, Traffic".
TCAS Altitudes*
Altitudes are displayed in hundreds of feet and relative to the altitude of the observing aircraft.
+01 = 100 feet higher
+10 = 1,000 feet higher
00 = Same altitude
-08 = 800 feet lower
-21 = 2,100 feet lower
*Flarm uses the same method to show altitudes.
Proximate TrafficAny traffic within 6 nautical miles and +/- 1,200 feet vertical.
This target is 1,000 feet lower and climbing by at least 500 feet/minute.
Other Traffic
Any traffic within TCAS range limit
This target is 2,700 higher than the viewer and descending by at least 500 feet/minute.
