Must say I am little scared after reading this thread.
Too many pilots think they allmost have "a radar" in their aircraft these days.
TCAS is a great last option tool...but really also give us ATCO's a LOT of grey hairs too because it's used/misused like a radar by many pilots.
TCAS is not a radar, for sure it shows you about which direction to look for traffic...HOWEVER...it doNOT show you which direction the traffic is moving!!
SO..turning in a RA situation...or even worse..turning to avoid a RA...is not the smart thing to do.
Give you an example...(out of memory from a incident I did read about some time ago).
Pilot see a target on his TCAS approaching him at same level from his 10 o'clock, for the pilot it looks like the traffic is heading direct for him. So with his smart thinking he turns right without telling ATC...to avoid any TCAS RA...result was...yes you guessed correct, a near miss and RA
What the pilot ofcourse couldnt't see on his TCAS was that the target was crossing in front of him with 5nm minimum sep. from left to right about 90degrees on his flightpath. So if he had stayed on course he would had seen the target approach him..then do a arcing movement around him from left to right..and leave behind at his 4 o'clock.
TCAS is NOT the same as RADAR, it do only show direction to target, not which way he is flying...so until TCAS has been improved and works both vertically
and horisontally...PLEASE..do not turn according to TCAS RA only!!!
Thanks
FinalVectors
ATCO