Narrative:

We were cleared for the runway 25L ILS approach outside of hunda intersection. We were told about traffic at 10 O'clock position and about 2 mi, a B757. We reported traffic in sight. We were told to maintain 180 KTS to the marker. As the captain intercepted the GS and started the descent, we received a TA from TCASII. In the next few seconds a lot of things were happening very fast. I first thought the TA was from the B757 at our 1 O'clock position going to runway 24R. I had him in sight and knew he wasn't a problem. Then we received our first RA which was to descend, followed by an RA to climb and then an RA to 'monitor vertical speed.' during this process I looked at the TCASII and noted traffic directly under and 200 ft below us. We never saw anything. The captain followed the RA to climb and climbed from about 2800-3100 ft MSL before RA ended. I asked lax tower if they had traffic at our position. They said, 'yes we have helicopter traffic below you.' ATC should have pointed out traffic before we approached their position and traffic should not be allowed that close to such a busy instrument approach.

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Original NASA ASRS Text

Title: ACR ACFT RECEIVED RA WHILE ON FINAL TO LAX. TFC HAD BEEN ISSUED ON PARALLEL BUT CTLR FAILED TO ADVISE PLT OF HELI OPERATING BELOW THE APCH.

Narrative: WE WERE CLRED FOR THE RWY 25L ILS APCH OUTSIDE OF HUNDA INTXN. WE WERE TOLD ABOUT TFC AT 10 O'CLOCK POS AND ABOUT 2 MI, A B757. WE RPTED TFC IN SIGHT. WE WERE TOLD TO MAINTAIN 180 KTS TO THE MARKER. AS THE CAPT INTERCEPTED THE GS AND STARTED THE DSCNT, WE RECEIVED A TA FROM TCASII. IN THE NEXT FEW SECONDS A LOT OF THINGS WERE HAPPENING VERY FAST. I FIRST THOUGHT THE TA WAS FROM THE B757 AT OUR 1 O'CLOCK POS GOING TO RWY 24R. I HAD HIM IN SIGHT AND KNEW HE WASN'T A PROB. THEN WE RECEIVED OUR FIRST RA WHICH WAS TO DSND, FOLLOWED BY AN RA TO CLB AND THEN AN RA TO 'MONITOR VERT SPD.' DURING THIS PROCESS I LOOKED AT THE TCASII AND NOTED TFC DIRECTLY UNDER AND 200 FT BELOW US. WE NEVER SAW ANYTHING. THE CAPT FOLLOWED THE RA TO CLB AND CLBED FROM ABOUT 2800-3100 FT MSL BEFORE RA ENDED. I ASKED LAX TWR IF THEY HAD TFC AT OUR POS. THEY SAID, 'YES WE HAVE HELI TFC BELOW YOU.' ATC SHOULD HAVE POINTED OUT TFC BEFORE WE APCHED THEIR POS AND TFC SHOULD NOT BE ALLOWED THAT CLOSE TO SUCH A BUSY INST APCH.

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.