Narrative:

Problem first started to develop when lax approach called out an air carrier medium large transport as traffic at 1 O'clock and about 4 or 5 mi. All crew members picked him up visly. He was in a right hand turn for a right base. Approach said he was on a visibility approach to runway 25R. As we continued the approach, the aircraft rolled out on what looked to be a heading of approximately 160 degrees. He was beginning to appear to be a conflict at this point, as it looked as though his flight path would cross in front of us. We were established on the localizer approach. The medium large transport finally began a right turn to final as he xed approximately 1 NM in front of us. Due to his apparent slow speed and turn we were quickly overtaking him. We maneuvered left of the localizer to avoid the medium large transport. By the time he rolled out on final, we were nearly abeam him (about 300'lateral sep), and about 100' above him. We were approximately 500' AGL about 1 1/2 NM from the runway, and well left of course. We thought at this point he was going to land on runway 25L. The decision was made to go around, just prior to the medium large transport rolling out on final, when we saw that it was not making any timely corrections to realign with runway 25R. On a subsequent approach to runway 25L, we measured the visibility to runway 25L at about 4 1/2 NM. It appeared the problem arose due to the mlgs loss of sight of the airfield. As a result, it appeared he used the localizer to runway 25L as a means to initiate a turn to final.

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Original NASA ASRS Text

Title: NMAC

Narrative: PROB FIRST STARTED TO DEVELOP WHEN LAX APCH CALLED OUT AN ACR MLG AS TFC AT 1 O'CLOCK AND ABOUT 4 OR 5 MI. ALL CREW MEMBERS PICKED HIM UP VISLY. HE WAS IN A R HAND TURN FOR A R BASE. APCH SAID HE WAS ON A VIS APCH TO RWY 25R. AS WE CONTINUED THE APCH, THE ACFT ROLLED OUT ON WHAT LOOKED TO BE A HDG OF APPROX 160 DEGS. HE WAS BEGINNING TO APPEAR TO BE A CONFLICT AT THIS POINT, AS IT LOOKED AS THOUGH HIS FLT PATH WOULD CROSS IN FRONT OF US. WE WERE ESTABLISHED ON THE LOC APCH. THE MLG FINALLY BEGAN A R TURN TO FINAL AS HE XED APPROX 1 NM IN FRONT OF US. DUE TO HIS APPARENT SLOW SPD AND TURN WE WERE QUICKLY OVERTAKING HIM. WE MANEUVERED L OF THE LOC TO AVOID THE MLG. BY THE TIME HE ROLLED OUT ON FINAL, WE WERE NEARLY ABEAM HIM (ABOUT 300'LATERAL SEP), AND ABOUT 100' ABOVE HIM. WE WERE APPROX 500' AGL ABOUT 1 1/2 NM FROM THE RWY, AND WELL L OF COURSE. WE THOUGHT AT THIS POINT HE WAS GOING TO LAND ON RWY 25L. THE DECISION WAS MADE TO GO AROUND, JUST PRIOR TO THE MLG ROLLING OUT ON FINAL, WHEN WE SAW THAT IT WAS NOT MAKING ANY TIMELY CORRECTIONS TO REALIGN WITH RWY 25R. ON A SUBSEQUENT APCH TO RWY 25L, WE MEASURED THE VISIBILITY TO RWY 25L AT ABOUT 4 1/2 NM. IT APPEARED THE PROB AROSE DUE TO THE MLGS LOSS OF SIGHT OF THE AIRFIELD. AS A RESULT, IT APPEARED HE USED THE LOC TO RWY 25L AS A MEANS TO INITIATE A TURN TO FINAL.

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.