After ATC said to expect runway 24R on the lax seavu arrival; 25L was assigned later. A track deviat...

Attributes
ACN	811437
Time
Date	200811
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl single value : 10000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	tracon : sct.tracon tracon : pct.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : seavu
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 293
ASRS Report	811437
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 134
ASRS Report	811652
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	flight crew : became reoriented flight crew : overcame equipment problem
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

On approach to lax; we were assigned runway 24R. Just before seavu intersection we were assigned runway 25L. I was the pm so I selected runway 25L in the FMC. When I looked at the new input there were only 3 waypoints on the new course. I informed the PF that this did not look right. I reselected the runway again; but the same thing came up. At this time we were close to seavu intersection; so I had the pm spell the luvyn intersection to me and I input it in the FMC. The airplane now had to fix to head to. I began to input all the waypoints one at a time. The pm was flying and doing all the stepdown fixes. At this point as I was inputting the fixes; I saw that the airplane did not turn on the course. I informed the pm the LNAV had kicked off and to turn left now. We made the turn; got back on course; and selected LNAV again. After that we did all the stepdown fixes with DME on the localizer. Supplemental information from acn 811652: just past pecos we were given runway 25L. Pm began programming runway 25L in the computer while I flew the arrival. Pm tried 2 times to enter runway 25L but was missing 5 intxns and the runway. Pm started entering all by hand while I continued to fly. On arrival at seavu pm had all the points in and we verified. I then verified we were proceeding to luvyn and continued the descent as published. Somewhere around luvyn; the LNAV 'kicked off.' we immediately turned toward krain to get back on the arrival. We are not sure exactly what happened. All was well briefed and verified. The LNAV was re-engaged once on course with no further problems. ATC was very busy. We were given runway 25L at the very last min. We did our best to get it in quickly. More heads up from ATC would have helped.

Original NASA ASRS Text

Title: AFTER ATC SAID TO EXPECT RUNWAY 24R ON THE LAX SEAVU ARRIVAL; 25L WAS ASSIGNED LATER. A TRACK DEVIATION OCCURRED WHEN THE FMC DID NOT ACCEPT THE ARRIVAL AND RUNWAY CHANGE.

Narrative: ON APCH TO LAX; WE WERE ASSIGNED RWY 24R. JUST BEFORE SEAVU INTXN WE WERE ASSIGNED RWY 25L. I WAS THE PM SO I SELECTED RWY 25L IN THE FMC. WHEN I LOOKED AT THE NEW INPUT THERE WERE ONLY 3 WAYPOINTS ON THE NEW COURSE. I INFORMED THE PF THAT THIS DID NOT LOOK RIGHT. I RESELECTED THE RWY AGAIN; BUT THE SAME THING CAME UP. AT THIS TIME WE WERE CLOSE TO SEAVU INTXN; SO I HAD THE PM SPELL THE LUVYN INTXN TO ME AND I INPUT IT IN THE FMC. THE AIRPLANE NOW HAD TO FIX TO HEAD TO. I BEGAN TO INPUT ALL THE WAYPOINTS ONE AT A TIME. THE PM WAS FLYING AND DOING ALL THE STEPDOWN FIXES. AT THIS POINT AS I WAS INPUTTING THE FIXES; I SAW THAT THE AIRPLANE DID NOT TURN ON THE COURSE. I INFORMED THE PM THE LNAV HAD KICKED OFF AND TO TURN L NOW. WE MADE THE TURN; GOT BACK ON COURSE; AND SELECTED LNAV AGAIN. AFTER THAT WE DID ALL THE STEPDOWN FIXES WITH DME ON THE LOC. SUPPLEMENTAL INFO FROM ACN 811652: JUST PAST PECOS WE WERE GIVEN RWY 25L. PM BEGAN PROGRAMMING RWY 25L IN THE COMPUTER WHILE I FLEW THE ARR. PM TRIED 2 TIMES TO ENTER RWY 25L BUT WAS MISSING 5 INTXNS AND THE RWY. PM STARTED ENTERING ALL BY HAND WHILE I CONTINUED TO FLY. ON ARR AT SEAVU PM HAD ALL THE POINTS IN AND WE VERIFIED. I THEN VERIFIED WE WERE PROCEEDING TO LUVYN AND CONTINUED THE DSCNT AS PUBLISHED. SOMEWHERE AROUND LUVYN; THE LNAV 'KICKED OFF.' WE IMMEDIATELY TURNED TOWARD KRAIN TO GET BACK ON THE ARR. WE ARE NOT SURE EXACTLY WHAT HAPPENED. ALL WAS WELL BRIEFED AND VERIFIED. THE LNAV WAS RE-ENGAGED ONCE ON COURSE WITH NO FURTHER PROBS. ATC WAS VERY BUSY. WE WERE GIVEN RWY 25L AT THE VERY LAST MIN. WE DID OUR BEST TO GET IT IN QUICKLY. MORE HEADS UP FROM ATC WOULD HAVE HELPED.

Data retrieved from NASA's ASRS site as of May 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.

After ATC said to expect runway 24R on the lax seavu arrival; 25L was assigned later. A track deviation occurred when the FMC did not accept the arrival and runway change.