DEP RWY WAS CHANGED AND FMC REPROGRAMMED. FLC DID NOT RECHK FMC PROGRAMMING. COURSE DEV OCCURRED DUE TO INADVERTENT FLC FMC PROGRAMMING.

Narrative

ASSIGNED RTE OUT OF LAX WAS A LOOP 9 DEP WITH A DAGGETT RWY TRANSITION. WE HAD PREPROGRAMMED THIS IN OUR FMC EXPECTING TO DEPART ON RWY 24L. A LAST MIN CHANGE AT THE RWY 24L; WE WERE SWITCHED TO RWY 24R. WE PUT RWY 24R IN THE FMC AND DEPARTED. WHAT WE DIDN'T KNOW WAS THAT BY CHANGING OUR RWY; THE WAYPOINTS ALSO CHANGED ON THE DEP. AFTER XING OVER THE ARPT AT 10000 FT AND COUPLED UP TO THE AUTOPLT THE ROUTING TOOK US FROM THE LAX VOR TO SEAL BEACH VOR. THIS IS WHEN THE DEP CTLR TOLD US WE WERE OFF COURSE AND CORRECTED US BACK ON COURSE WITH HDG CHANGES. NO TFC CONFLICTS OCCURRED. AFTER WE WERE BACK ON COURSE WE PLAYED WITH OUR FMC COMPUTERS AND FOUND THAT IF YOU DON'T RESELECT THE DEP AND TRANSITION AFTER CHANGING RWYS; YOU GET THE WRONG ROUTING. CORRECT ROUTING IS CROSS LAX VOR AT 10000 FT OR ABOVE OUTBOUND ON THE LAX 041 DEG RADIAL OVER KEGGS AND COOPP INTXNS TO DAGGETT VOR. THIS WAS VERIFIED IN OUR PREFLT CHKS. AFTER CHANGING FROM RWY 24L TO RWY 24R THE ROUTING WAS NOT RECHKED AND CAME UP CROSS THE LAX VOR AT 10000 FT OR ABOVE DIRECT SEAL BEACH VOR THEN DEPART SEAL BEACH ON THE SEAL BEACH 003 DEG RADIAL TO THE F060X FIX WHICH IS THE SEAL BEACH 003 DEG RADIAL 20 NM TO INTERCEPT THE DAGGETT 222 DEG RADIAL TO DAGGETT. THIS CAN BE AVOIDED BY RESELECTING THE DEP SID AND TRANSITION AFTER RESELECTING A RWY. OUR FLEET MGR WILL BE INFORMED OF THIS AND A REMINDER TO OTHER 757 PLTS WILL BE SENT OUT SO THIS DOESN'T HAPPEN TO OTHER PLTS IN THE FUTURE.