Heading track deviation places other air carrier in closer proximity to reporter's than planned.

Attributes
ACN	282108
Time
Date	199409
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 2000 msl bound upper : 2000
Environment
Flight Conditions	Marginal
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : visual arrival other arrival star : star
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 11000 flight time type : 2000
ASRS Report	282108
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 3000 vertical : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

As we were turned onto final we had a target on the TCASII very close (on TCASII) at 10 O'clock position with 500 ft below us. Expecting a RA we reduced our descent (we did not have visual) we maintained about 400 ft separation 'til we had the aircraft (a 727 to runway 24L) in sight. By then we had crossed over final (to runway 24R) and were about 1/2 way between the runways. We then corrected back to runway 24R. Cause: the TCASII diverted our attention to traffic we were not advised of by ATC. Ready to do a RA deviation, our attention was on TCASII and not turning final. We did not know the traffic we were avoiding was on final to runway 24L. Visibility was poor at dusk with haze.

Original NASA ASRS Text

Title: HDG TRACK DEV PLACES OTHER ACR IN CLOSER PROX TO RPTR'S THAN PLANNED.

Narrative: AS WE WERE TURNED ONTO FINAL WE HAD A TARGET ON THE TCASII VERY CLOSE (ON TCASII) AT 10 O'CLOCK POS WITH 500 FT BELOW US. EXPECTING A RA WE REDUCED OUR DSCNT (WE DID NOT HAVE VISUAL) WE MAINTAINED ABOUT 400 FT SEPARATION 'TIL WE HAD THE ACFT (A 727 TO RWY 24L) IN SIGHT. BY THEN WE HAD CROSSED OVER FINAL (TO RWY 24R) AND WERE ABOUT 1/2 WAY BTWN THE RWYS. WE THEN CORRECTED BACK TO RWY 24R. CAUSE: THE TCASII DIVERTED OUR ATTN TO TFC WE WERE NOT ADVISED OF BY ATC. READY TO DO A RA DEV, OUR ATTN WAS ON TCASII AND NOT TURNING FINAL. WE DID NOT KNOW THE TFC WE WERE AVOIDING WAS ON FINAL TO RWY 24L. VISIBILITY WAS POOR AT DUSK WITH HAZE.

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.