Narrative:

Air carrier X cleared for the ILS 25L at lax. Night VFR conditions. Approach asked us 3 times if we saw the airport. Obviously, they really wanted to give us a visual approach. When we finally picked out the runway, amidst all the lights, they immediately told us to sidestep to the right side runway 25R and they told us there was aircraft Y in our 8 O'clock position that was going to land on the left side. Very shortly thereafter, we received a TA on TCASII. The aircraft was moving in from behind us. We continued our approach. Shortly afterward, we received an RA telling us to slow our descent rate. We leveled off so that the warning (aural warning) stopped, but the TCASII still showed red and the vsi indicator would not let us descend because of the other aircraft. This scenario started at approximately 10 mi out, and by about 4 mi out, the TCASII guaranteed that we were in no position to land. I told the tower that we had a TCASII advisory and that we couldn't descend with that aircraft there. The approach controller asked the other aircraft if they had us in sight. The other said that they did have us in sight. The problem is that we could not see the other aircraft, and more importantly, we could not descend and ignore the TCASII warning. Company policy, FAA, and common sense dictate that an RA should not be ignored. I told the tower we would have to go around. I believe that we made the proper decisions and took the proper actions, considering the situation.

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Original NASA ASRS Text

Title: ACR X TCASII RA WITH Y ON PARALLEL RWY MADE MISSED APCH. NON ADHERENCE TO ATC CLRNC.

Narrative: ACR X CLRED FOR THE ILS 25L AT LAX. NIGHT VFR CONDITIONS. APCH ASKED US 3 TIMES IF WE SAW THE ARPT. OBVIOUSLY, THEY REALLY WANTED TO GIVE US A VISUAL APCH. WHEN WE FINALLY PICKED OUT THE RWY, AMIDST ALL THE LIGHTS, THEY IMMEDIATELY TOLD US TO SIDESTEP TO THE R SIDE RWY 25R AND THEY TOLD US THERE WAS ACFT Y IN OUR 8 O'CLOCK POS THAT WAS GOING TO LAND ON THE L SIDE. VERY SHORTLY THEREAFTER, WE RECEIVED A TA ON TCASII. THE ACFT WAS MOVING IN FROM BEHIND US. WE CONTINUED OUR APCH. SHORTLY AFTERWARD, WE RECEIVED AN RA TELLING US TO SLOW OUR DSCNT RATE. WE LEVELED OFF SO THAT THE WARNING (AURAL WARNING) STOPPED, BUT THE TCASII STILL SHOWED RED AND THE VSI INDICATOR WOULD NOT LET US DSND BECAUSE OF THE OTHER ACFT. THIS SCENARIO STARTED AT APPROX 10 MI OUT, AND BY ABOUT 4 MI OUT, THE TCASII GUARANTEED THAT WE WERE IN NO POS TO LAND. I TOLD THE TWR THAT WE HAD A TCASII ADVISORY AND THAT WE COULDN'T DSND WITH THAT ACFT THERE. THE APCH CTLR ASKED THE OTHER ACFT IF THEY HAD US IN SIGHT. THE OTHER SAID THAT THEY DID HAVE US IN SIGHT. THE PROB IS THAT WE COULD NOT SEE THE OTHER ACFT, AND MORE IMPORTANTLY, WE COULD NOT DSND AND IGNORE THE TCASII WARNING. COMPANY POLICY, FAA, AND COMMON SENSE DICTATE THAT AN RA SHOULD NOT BE IGNORED. I TOLD THE TWR WE WOULD HAVE TO GAR. I BELIEVE THAT WE MADE THE PROPER DECISIONS AND TOOK THE PROPER ACTIONS, CONSIDERING THE SIT.

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.