Narrative:

I was captain on flight from sfo to lax as first officer flew leg to lax. WX was clear, 5 mi visibility, haze with west sun (XX00L) we were cleared for stadium visual approach runway 24R after we called preceding aircraft in sight. On base turn gear was lower, flaps 10 degrees, speed 180 KTS. During the start of turn to final I saw a commuter aircraft also turning base to final runway 25, this traffic was co-altitude, belly-up to us, and not called out by approach or tower. During our turn to final I told first officer to increase bank and turn as I kept traffic in sight. I maintained visual contact throughout the turn to assure separation since we were on different frequencys and did not know if the traffic had us in sight. We received a single TCASII RA 'monitor vertical speed,' while in the turn. As we rolled out the first officer lined up on centerline and we continued a normal, stabilized approach, contacted tower and landed normally. The following day was advised of possible loss of separation from other aircraft. ATC had said nothing. Contributing factors to be considered: sun, haze, following preceding aircraft on visual approach without runway in sight, no call by ATC of runway 25 traffic while on different frequencys, both aircraft belly-up at same point in turn at same altitude, need to feel I had to keep traffic in sight, scheduling may be considered a factor (shuttle operations, 6TH flight of the day, 3RD aircraft of day) although neither the first officer or myself considered ourselves fatigued.

Related reports:

Google
 

Original NASA ASRS Text

Title: MLG FLC ON VISUAL INTO LAX FINDS THEMSELVES BELLY UP TO COMMUTER TURNING FINAL FOR OTHER RWYS. MAINTAIN VISUAL CONTACT WITH THE SECOND ACFT.

Narrative: I WAS CAPT ON FLT FROM SFO TO LAX AS FO FLEW LEG TO LAX. WX WAS CLR, 5 MI VISIBILITY, HAZE WITH W SUN (XX00L) WE WERE CLRED FOR STADIUM VISUAL APCH RWY 24R AFTER WE CALLED PRECEDING ACFT IN SIGHT. ON BASE TURN GEAR WAS LOWER, FLAPS 10 DEGS, SPD 180 KTS. DURING THE START OF TURN TO FINAL I SAW A COMMUTER ACFT ALSO TURNING BASE TO FINAL RWY 25, THIS TFC WAS CO-ALT, BELLY-UP TO US, AND NOT CALLED OUT BY APCH OR TWR. DURING OUR TURN TO FINAL I TOLD FO TO INCREASE BANK AND TURN AS I KEPT TFC IN SIGHT. I MAINTAINED VISUAL CONTACT THROUGHOUT THE TURN TO ASSURE SEPARATION SINCE WE WERE ON DIFFERENT FREQS AND DID NOT KNOW IF THE TFC HAD US IN SIGHT. WE RECEIVED A SINGLE TCASII RA 'MONITOR VERT SPD,' WHILE IN THE TURN. AS WE ROLLED OUT THE FO LINED UP ON CTRLINE AND WE CONTINUED A NORMAL, STABILIZED APCH, CONTACTED TWR AND LANDED NORMALLY. THE FOLLOWING DAY WAS ADVISED OF POSSIBLE LOSS OF SEPARATION FROM OTHER ACFT. ATC HAD SAID NOTHING. CONTRIBUTING FACTORS TO BE CONSIDERED: SUN, HAZE, FOLLOWING PRECEDING ACFT ON VISUAL APCH WITHOUT RWY IN SIGHT, NO CALL BY ATC OF RWY 25 TFC WHILE ON DIFFERENT FREQS, BOTH ACFT BELLY-UP AT SAME POINT IN TURN AT SAME ALT, NEED TO FEEL I HAD TO KEEP TFC IN SIGHT, SCHEDULING MAY BE CONSIDERED A FACTOR (SHUTTLE OPS, 6TH FLT OF THE DAY, 3RD ACFT OF DAY) ALTHOUGH NEITHER THE FO OR MYSELF CONSIDERED OURSELVES FATIGUED.

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.