An air carrier flight crew deviated from the assigned track on arrival into lax.

Attributes
ACN	761220
Time
Date	200711
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl single value : 13000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : civet
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 247 flight time type : 7000
ASRS Report	761220
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 96
ASRS Report	761209
Events
Anomaly	altitude deviation : crossing restriction not met other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued advisory flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

On arrival on the civet 5 into lax we were descending via the runway 24R transition instead of runway 25L transition. I was very busy trying to instruct the first officer on the arrival descent profile and missed the transition error. ATC called us slightly right of course and asked if we were correcting. We told them we were showing on course descending via civet 5 runway 24R. They came back with you were cleared descend via civet 5 runway 25L. We were approximately 45 mi out with 12000 ft in the MCP. We corrected back left to runway 25L and may have been slightly high on the next altitude restr; however; ATC gave us an at or above clearance.

Original NASA ASRS Text

Title: AN ACR FLT CREW DEVIATED FROM THE ASSIGNED TRACK ON ARRIVAL INTO LAX.

Narrative: ON ARR ON THE CIVET 5 INTO LAX WE WERE DSNDING VIA THE RWY 24R TRANSITION INSTEAD OF RWY 25L TRANSITION. I WAS VERY BUSY TRYING TO INSTRUCT THE FO ON THE ARR DSCNT PROFILE AND MISSED THE TRANSITION ERROR. ATC CALLED US SLIGHTLY R OF COURSE AND ASKED IF WE WERE CORRECTING. WE TOLD THEM WE WERE SHOWING ON COURSE DSNDING VIA CIVET 5 RWY 24R. THEY CAME BACK WITH YOU WERE CLRED DSND VIA CIVET 5 RWY 25L. WE WERE APPROX 45 MI OUT WITH 12000 FT IN THE MCP. WE CORRECTED BACK L TO RWY 25L AND MAY HAVE BEEN SLIGHTLY HIGH ON THE NEXT ALT RESTR; HOWEVER; ATC GAVE US AN AT OR ABOVE CLRNC.

Data retrieved from NASA's ASRS site as of January 2009 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.