Narrative:

On downwind from smo we were asked to turn base leg in the area of the coliseum. Having the airport in sight and the preceding airplane on short final (for 24R), we were given a visual approach (also for 24). On about a 2 mi final we were issued traffic at 2 O'clock, and were told that it would pass over and behind for 24L. Between 1000 ft and 500 ft we received a TCASII RA along with the aural warnings. Traffic was noted to the right and slightly behind, we immediately increased our descent according to the red avoidance area, then of course we received the 'monitor vertical speed' and 'below GS' warnings! Approximately 20 seconds later I observed a commuter aircraft wingtip to wingtip for 24L. As our airspeed was somewhere around 140 KTS, I wonder how he could come over the top of us and catch up so as to be abeam from a downwind leg! I feel the practice of crossing aircraft, where only 1 aircraft has visual contact with the other aircraft, is dangerous. Under the circumstances, we should have been given the left runway and the commuter the right. Also mutual visual contact should be maintained by both pilots at all times. (The runways are only 800 ft apart.) instances such as this are particularly unnerving, especially in a TCASII environment. This adds additional confusion with loud aural warnings at a time when the workload is at its highest. I would like to see greater separation for arriving aircraft. As a further suggestion, for safety, the commuter should have been told to remain at least 1 mi behind.

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Original NASA ASRS Text

Title: ACR MLG DSNDED BELOW GS ON STADIUM VISUAL AT LAX IN RESPONSE TO TCASII RA.

Narrative: ON DOWNWIND FROM SMO WE WERE ASKED TO TURN BASE LEG IN THE AREA OF THE COLISEUM. HAVING THE ARPT IN SIGHT AND THE PRECEDING AIRPLANE ON SHORT FINAL (FOR 24R), WE WERE GIVEN A VISUAL APCH (ALSO FOR 24). ON ABOUT A 2 MI FINAL WE WERE ISSUED TFC AT 2 O'CLOCK, AND WERE TOLD THAT IT WOULD PASS OVER AND BEHIND FOR 24L. BTWN 1000 FT AND 500 FT WE RECEIVED A TCASII RA ALONG WITH THE AURAL WARNINGS. TFC WAS NOTED TO THE R AND SLIGHTLY BEHIND, WE IMMEDIATELY INCREASED OUR DSCNT ACCORDING TO THE RED AVOIDANCE AREA, THEN OF COURSE WE RECEIVED THE 'MONITOR VERT SPD' AND 'BELOW GS' WARNINGS! APPROX 20 SECONDS LATER I OBSERVED A COMMUTER ACFT WINGTIP TO WINGTIP FOR 24L. AS OUR AIRSPD WAS SOMEWHERE AROUND 140 KTS, I WONDER HOW HE COULD COME OVER THE TOP OF US AND CATCH UP SO AS TO BE ABEAM FROM A DOWNWIND LEG! I FEEL THE PRACTICE OF XING ACFT, WHERE ONLY 1 ACFT HAS VISUAL CONTACT WITH THE OTHER ACFT, IS DANGEROUS. UNDER THE CIRCUMSTANCES, WE SHOULD HAVE BEEN GIVEN THE L RWY AND THE COMMUTER THE R. ALSO MUTUAL VISUAL CONTACT SHOULD BE MAINTAINED BY BOTH PLTS AT ALL TIMES. (THE RWYS ARE ONLY 800 FT APART.) INSTANCES SUCH AS THIS ARE PARTICULARLY UNNERVING, ESPECIALLY IN A TCASII ENVIRONMENT. THIS ADDS ADDITIONAL CONFUSION WITH LOUD AURAL WARNINGS AT A TIME WHEN THE WORKLOAD IS AT ITS HIGHEST. I WOULD LIKE TO SEE GREATER SEPARATION FOR ARRIVING ACFT. AS A FURTHER SUGGESTION, FOR SAFETY, THE COMMUTER SHOULD HAVE BEEN TOLD TO REMAIN AT LEAST 1 MI BEHIND.

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.