Narrative:

Controled by atl approach, turned from downwind leg to base, about 10 mi. Instructed to keep speed at 210 KIAS by ATC. Traffic pointed out by ATC and spotted by both pilots. Told to follow traffic and cleared visual approach, started to decrease speed and configure aircraft for landing. As approach commenced, I mistakenly idented another aircraft for the one I was supposed to follow. The aircraft I saw was on final to runway 27L (I was cleared runway 26R). My airspeed was about 190 KIAS when I saw the localizer course for runway 26R rapidly move off the wall. I turned to intercept, but overshot, causing the TCASII TA and RA. RA was 'reduce vertical speed.' I continued to intercept the localizer without further incidents.

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Original NASA ASRS Text

Title: B727 FO, PF, OVERSHOT THE LOC COURSE AS HE FIXATED ON THE WRONG ACFT TO FOLLOW FOR A VISUAL TO RWY 26R. OTHER ACFT WAS ON AN APCH TO RWY 27L. TCASII TA RA ALERTED HIM TO THE POTENTIAL CONFLICT.

Narrative: CTLED BY ATL APCH, TURNED FROM DOWNWIND LEG TO BASE, ABOUT 10 MI. INSTRUCTED TO KEEP SPD AT 210 KIAS BY ATC. TFC POINTED OUT BY ATC AND SPOTTED BY BOTH PLTS. TOLD TO FOLLOW TFC AND CLRED VISUAL APCH, STARTED TO DECREASE SPD AND CONFIGURE ACFT FOR LNDG. AS APCH COMMENCED, I MISTAKENLY IDENTED ANOTHER ACFT FOR THE ONE I WAS SUPPOSED TO FOLLOW. THE ACFT I SAW WAS ON FINAL TO RWY 27L (I WAS CLRED RWY 26R). MY AIRSPD WAS ABOUT 190 KIAS WHEN I SAW THE LOC COURSE FOR RWY 26R RAPIDLY MOVE OFF THE WALL. I TURNED TO INTERCEPT, BUT OVERSHOT, CAUSING THE TCASII TA AND RA. RA WAS 'REDUCE VERT SPD.' I CONTINUED TO INTERCEPT THE LOC WITHOUT FURTHER INCIDENTS.

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.