B757 crew descends below assigned altitude after late runway change on civet 5 into lax.

Attributes
ACN	734695
Time
Date	200704
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl bound lower : 11400 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival star : civet
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	734695
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	734694
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Altitude deviation occurred at 12000 ft at cadmi fix on the civet runway 24R arrival at lax. Within 20 mi switched FMC runways from runway 25R to runway 25L to runway 24R. During the switch to runway 24R given direct to cadmi after having passed gramm. Was expediting descent to 12000 ft when copilot asked if he should put in 8000 ft for the arrival. He thought we were still in VNAV when we were actually in flight level change. I was trying to get my map page updated. The copilot called 12000 ft when we were 5 mi prior to cadmi. We sank to around 11400 ft and corrected. No calls by ATC. Lots of things going on and it will probably happen again to other crews getting late runway switches at lax. We were assigned 290 KIAS on the speed at the time.

Original NASA ASRS Text

Title: B757 CREW DESCENDS BELOW ASSIGNED ALTITUDE AFTER LATE RUNWAY CHANGE ON CIVET 5 INTO LAX.

Narrative: ALTDEV OCCURRED AT 12000 FT AT CADMI FIX ON THE CIVET RWY 24R ARR AT LAX. WITHIN 20 MI SWITCHED FMC RWYS FROM RWY 25R TO RWY 25L TO RWY 24R. DURING THE SWITCH TO RWY 24R GIVEN DIRECT TO CADMI AFTER HAVING PASSED GRAMM. WAS EXPEDITING DSCNT TO 12000 FT WHEN COPLT ASKED IF HE SHOULD PUT IN 8000 FT FOR THE ARR. HE THOUGHT WE WERE STILL IN VNAV WHEN WE WERE ACTUALLY IN FLT LEVEL CHANGE. I WAS TRYING TO GET MY MAP PAGE UPDATED. THE COPLT CALLED 12000 FT WHEN WE WERE 5 MI PRIOR TO CADMI. WE SANK TO AROUND 11400 FT AND CORRECTED. NO CALLS BY ATC. LOTS OF THINGS GOING ON AND IT WILL PROBABLY HAPPEN AGAIN TO OTHER CREWS GETTING LATE RWY SWITCHES AT LAX. WE WERE ASSIGNED 290 KIAS ON THE SPD AT THE TIME.

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.