Narrative:

After briefing civet 4 arrival and ILS runway 25L, we were given a vector then reclred for the mitts 1 arrival. We were held at 12000 ft approaching snrkl int and asked if we had traffic off our left. After calling traffic in sight we were asked to maintain visual. We were then cleared to snrkl at 12000 ft and for the mitts 1 arrival. The traffic was abeam and appeared to be appropriate distance for runway 25L final. We then noticed that traffic was beginning to encroach on our flight path and thought that he might be overshooting slightly but did not seem of immediate concern. Traffic continued to get closer and now had our attention. First officer began a shallow turn to the right to allow for a little more room while still on course when about this time we got TCASII TA followed shortly by an RA to descend which we complied with and advised ATC. ATC responded that we could resume approach after complying. Clear of conflict was received at approximately 8700 ft approaching jonzz intersection. We elected to not climb back toward traffic while we checked for appropriate altitude on the chart for our present position. We then continued to descend on the arrival and approach. Aftr landing ATC supervisor told me that there were some paradise arrival about the time we experienced the RA and that due to intercept angle of 30 degrees to the runway 25L localizer and our final approach course and possible slight overshoot was likely reason for RA. This situation should be avoided. Supplemental information from acn 496359: with assigned path altitude and airspeed how do I maintain separation? Are these two arrival procedures compatible?

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Original NASA ASRS Text

Title: LAST MIN RWY APCH CHANGE, USE OF VISUAL SEPARATION, AND A SLIGHT OVERSHOOT FROM A THIRTY DEG INTERCEPT RESULT IN A TFC CONFLICT AND TCAS RESOULUTION ADVISORY ON ARR FROM THE E AT LAX, CA.

Narrative: AFTER BRIEFING CIVET 4 ARR AND ILS RWY 25L, WE WERE GIVEN A VECTOR THEN RECLRED FOR THE MITTS 1 ARR. WE WERE HELD AT 12000 FT APCHING SNRKL INT AND ASKED IF WE HAD TFC OFF OUR L. AFTER CALLING TFC IN SIGHT WE WERE ASKED TO MAINTAIN VISUAL. WE WERE THEN CLRED TO SNRKL AT 12000 FT AND FOR THE MITTS 1 ARR. THE TFC WAS ABEAM AND APPEARED TO BE APPROPRIATE DISTANCE FOR RWY 25L FINAL. WE THEN NOTICED THAT TFC WAS BEGINNING TO ENCROACH ON OUR FLT PATH AND THOUGHT THAT HE MIGHT BE OVERSHOOTING SLIGHTLY BUT DID NOT SEEM OF IMMEDIATE CONCERN. TFC CONTINUED TO GET CLOSER AND NOW HAD OUR ATTENTION. FO BEGAN A SHALLOW TURN TO THE R TO ALLOW FOR A LITTLE MORE ROOM WHILE STILL ON COURSE WHEN ABOUT THIS TIME WE GOT TCASII TA FOLLOWED SHORTLY BY AN RA TO DSND WHICH WE COMPLIED WITH AND ADVISED ATC. ATC RESPONDED THAT WE COULD RESUME APCH AFTER COMPLYING. CLR OF CONFLICT WAS RECEIVED AT APPROX 8700 FT APCHING JONZZ INTXN. WE ELECTED TO NOT CLB BACK TOWARD TFC WHILE WE CHKED FOR APPROPRIATE ALT ON THE CHART FOR OUR PRESENT POS. WE THEN CONTINUED TO DSND ON THE ARR AND APCH. AFTR LNDG ATC SUPVR TOLD ME THAT THERE WERE SOME PARADISE ARR ABOUT THE TIME WE EXPERIENCED THE RA AND THAT DUE TO INTERCEPT ANGLE OF 30 DEGS TO THE RWY 25L LOC AND OUR FINAL APCH COURSE AND POSSIBLE SLIGHT OVERSHOOT WAS LIKELY REASON FOR RA. THIS SIT SHOULD BE AVOIDED. SUPPLEMENTAL INFO FROM ACN 496359: WITH ASSIGNED PATH ALT AND AIRSPEED HOW DO I MAINTAIN SEPARATION? ARE THESE TWO ARR PROCS COMPATIBLE?

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.