Narrative:

Air carrier X slc-sna, first officer flying. Inbound sna east side 1 FMS arrival approximately position FO29L. Socal approach issued a left turn to 270 degree and descent to 3000 ft passing through approximately 4000 ft approach issued right turn (to 330 degree) for traffic avoidance. A matter of seconds later a TCASII RA occurred, directing a 'climb maneuver of 2000-2500 FPM. Socal approach was immediately advised of our response to the RA (by me) as the first officer disconnected the autoplt and initiated the maneuver. As the maneuver was initiated the conflicting traffic was observed on TCASII at approximately 10 O'clock, rapidly climbing from white to yellow to the red RA. When 'clear of conflict' message was received and recovery completed our aircraft was at 6000 ft.socal approach vectored us to intercept ILS runway 19R at sna and a normal approach and landing was accomplished. After deplaning I responded to a request from socal approach to contact them. I spoke with a supervisor. We discussed the altitude at which the RA occurred, joint concerns reference the near miss, and he indicated that socal approach quality assurance would investigate the incident. TCASII works!! - In this case, in all likelihood, it saved a couple of hundred lives as well as 2 aircraft. We never saw the RA traffic visually, so, without TCASII the best we could have hoped for was a near miss.

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Original NASA ASRS Text

Title: ACR X TCASII RA WITH PROBABLE VFR ACFT EVASIVE ACTION TAKEN. POSSIBLE TCASII INDUCED LTSS WITH ANOTHER ACFT.

Narrative: ACR X SLC-SNA, FO FLYING. INBOUND SNA E SIDE 1 FMS ARR APPROX POS FO29L. SOCAL APCH ISSUED A L TURN TO 270 DEG AND DSCNT TO 3000 FT PASSING THROUGH APPROX 4000 FT APCH ISSUED R TURN (TO 330 DEG) FOR TFC AVOIDANCE. A MATTER OF SECONDS LATER A TCASII RA OCCURRED, DIRECTING A 'CLB MANEUVER OF 2000-2500 FPM. SOCAL APCH WAS IMMEDIATELY ADVISED OF OUR RESPONSE TO THE RA (BY ME) AS THE FO DISCONNECTED THE AUTOPLT AND INITIATED THE MANEUVER. AS THE MANEUVER WAS INITIATED THE CONFLICTING TFC WAS OBSERVED ON TCASII AT APPROX 10 O'CLOCK, RAPIDLY CLBING FROM WHITE TO YELLOW TO THE RED RA. WHEN 'CLR OF CONFLICT' MESSAGE WAS RECEIVED AND RECOVERY COMPLETED OUR ACFT WAS AT 6000 FT.SOCAL APCH VECTORED US TO INTERCEPT ILS RWY 19R AT SNA AND A NORMAL APCH AND LNDG WAS ACCOMPLISHED. AFTER DEPLANING I RESPONDED TO A REQUEST FROM SOCAL APCH TO CONTACT THEM. I SPOKE WITH A SUPVR. WE DISCUSSED THE ALT AT WHICH THE RA OCCURRED, JOINT CONCERNS REF THE NEAR MISS, AND HE INDICATED THAT SOCAL APCH QUALITY ASSURANCE WOULD INVESTIGATE THE INCIDENT. TCASII WORKS!! - IN THIS CASE, IN ALL LIKELIHOOD, IT SAVED A COUPLE OF HUNDRED LIVES AS WELL AS 2 ACFT. WE NEVER SAW THE RA TFC VISUALLY, SO, WITHOUT TCASII THE BEST WE COULD HAVE HOPED FOR WAS A NEAR MISS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.