Narrative:

Aircraft (SF340B) was in the base turn during transition from vectors to a visual approach, following another aircraft (MD80) for a visual approach to runway 24R at lax. PF was first officer on right side of aircraft making right turns to base and to final. During base to final, I lowered the gear and completed the associated flow items. I was about to suggest to the first officer to turn inside the localizer final approach course (north of course) to avoid wake turbulence when we noted that we were a DOT high on the GS and we would be above the wake turbulence. I felt that this would safely avoid the turbulence and didn't feel a need to comment on my idea. As we started our turn to final, I saw an aircraft crossing the harbor freeway, that I thought was the traffic we were to follow (but turned out to be a DC9 inbound for runway 25) and estimated that we were about 3 mi in trail and above the GS. The airport was about 13 mi from our position. As we started our right turn to final, I checked to my left and saw a B767 about 2 mi away and on what seemed to be a converging course and at the same altitude. I advised the first officer to tighten up the right turn, continuing northwestward and to climb to avoid the traffic. As I was saying this, we both realized that we were south of the runway 24R localizer. As we corrected north, I advised approach that we were correcting north. The first officer noted that the autoplt had not captured the final approach as it was set up to do. We corrected to the runway 24R localizer and landed at lax. A major contributing factor that would have prevented this event was that we did not have a working TCASII system. It had been previously deferred. Had this system been working, it would have allowed me to realize that there were 2 aircraft on finals ahead of us (one for the south complex and one for the north complex). It would have reduced my concerns of wake turbulence. Plus I would have 'seen' the B767 earlier in the approach on the TCASII. Another factor was that the visibility was about 5 mi in haze at the time. This allowed me to think I saw our traffic-to-follow when in fact, it was traffic for another runway.

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Original NASA ASRS Text

Title: SF34 FLC OVERSHOOTS FINAL WHILE DISTRACTED BY OTHER ACFT ON PARALLEL APCHS TO LAX.

Narrative: ACFT (SF340B) WAS IN THE BASE TURN DURING TRANSITION FROM VECTORS TO A VISUAL APCH, FOLLOWING ANOTHER ACFT (MD80) FOR A VISUAL APCH TO RWY 24R AT LAX. PF WAS FO ON R SIDE OF ACFT MAKING R TURNS TO BASE AND TO FINAL. DURING BASE TO FINAL, I LOWERED THE GEAR AND COMPLETED THE ASSOCIATED FLOW ITEMS. I WAS ABOUT TO SUGGEST TO THE FO TO TURN INSIDE THE LOC FINAL APCH COURSE (N OF COURSE) TO AVOID WAKE TURB WHEN WE NOTED THAT WE WERE A DOT HIGH ON THE GS AND WE WOULD BE ABOVE THE WAKE TURB. I FELT THAT THIS WOULD SAFELY AVOID THE TURB AND DIDN'T FEEL A NEED TO COMMENT ON MY IDEA. AS WE STARTED OUR TURN TO FINAL, I SAW AN ACFT XING THE HARBOR FREEWAY, THAT I THOUGHT WAS THE TFC WE WERE TO FOLLOW (BUT TURNED OUT TO BE A DC9 INBOUND FOR RWY 25) AND ESTIMATED THAT WE WERE ABOUT 3 MI IN TRAIL AND ABOVE THE GS. THE ARPT WAS ABOUT 13 MI FROM OUR POS. AS WE STARTED OUR R TURN TO FINAL, I CHKED TO MY L AND SAW A B767 ABOUT 2 MI AWAY AND ON WHAT SEEMED TO BE A CONVERGING COURSE AND AT THE SAME ALT. I ADVISED THE FO TO TIGHTEN UP THE R TURN, CONTINUING NORTHWESTWARD AND TO CLB TO AVOID THE TFC. AS I WAS SAYING THIS, WE BOTH REALIZED THAT WE WERE S OF THE RWY 24R LOC. AS WE CORRECTED N, I ADVISED APCH THAT WE WERE CORRECTING N. THE FO NOTED THAT THE AUTOPLT HAD NOT CAPTURED THE FINAL APCH AS IT WAS SET UP TO DO. WE CORRECTED TO THE RWY 24R LOC AND LANDED AT LAX. A MAJOR CONTRIBUTING FACTOR THAT WOULD HAVE PREVENTED THIS EVENT WAS THAT WE DID NOT HAVE A WORKING TCASII SYS. IT HAD BEEN PREVIOUSLY DEFERRED. HAD THIS SYS BEEN WORKING, IT WOULD HAVE ALLOWED ME TO REALIZE THAT THERE WERE 2 ACFT ON FINALS AHEAD OF US (ONE FOR THE S COMPLEX AND ONE FOR THE N COMPLEX). IT WOULD HAVE REDUCED MY CONCERNS OF WAKE TURB. PLUS I WOULD HAVE 'SEEN' THE B767 EARLIER IN THE APCH ON THE TCASII. ANOTHER FACTOR WAS THAT THE VISIBILITY WAS ABOUT 5 MI IN HAZE AT THE TIME. THIS ALLOWED ME TO THINK I SAW OUR TFC-TO-FOLLOW WHEN IN FACT, IT WAS TFC FOR ANOTHER RWY.

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.