A CPR SMT INBOUND ON THE SADDE ARR TO LAX COPIED A DSCNT AND TURN CLRNC FOR ANOTHER ACFT. APCH CTLR CAUGHT THE ERROR AFTER THE ACFT COMPLETED THE TURN AND VECTORED THE SMT BACK ON THE ARR. NO SEPARATION WAS LOST.

Narrative

AS WE APCHED SYMON INTXN ON THE SADDE ARR INTO LAX; THE CTLR GAVE US A CLRNC TO DEPART SMO (SANTA MONICA) ON A HDG OF 070 DEGS; BUT TO REMAIN ON THE ARR UNTIL SMO. WE ACKNOWLEDGED THAT CLRNC. A SHORT TIME LATER AT APPROX XA05 LCL; WE HEARD A CLRNC TO PROCEED DIRECT TO SMO; MAINTAIN 7000 FT AND 180 KTS. WE ACKNOWLEDGED WITH OUR CALL SIGN. SHORTLY AFTER COMPLETING OUR TURN TO SMO (WE WERE STILL ABOVE OUR PREVIOUS ASSIGNED ALT AND DSNDING); THE CTLR CALLED US AND ASKED US OUR HEADING. WE REPLIED 095 DEGS. HE STATED THAT WE WERE SUPPOSED TO BE HEADING FOR (UNINTELLIGIBLE) INTXN (ON THE SADDE ARR). I IMMEDIATELY TURNED TO HIS ASSIGNED HEADING OF 180 DEGS TO RE-INTERCEPT THE ARR AND TOLD HIM THAT I HAD COPIED THE DIRECT SMO 7000 FT 180 KTS ASSIGNMENT. HE STATED THAT WE HAD COPIED ANOTHER ACFT'S CLRNC. AT THAT POINT ANOTHER ACFT STATED 'WHO WAS THE CLRNC FOR?' AND THE CTLR STATED THAT IT WAS FOR HIM. IF IT WAS; HE HADN'T HEARD IT AS SUCH. 1) THE CTLR WAS VERY BUSY AT THIS TIME WITH AT LEAST 3 ACFT; ARRIVING FOR THE SADDE ARR AT VERY CLOSE INTERVALS. 2) WE READ BACK THE NEWLY ASSIGNED CLRNC (WHICH WAS APPARENTLY NOT FOR US) AND STATED OUR CALL SIGN WITH NO REPLY OR CORRECTION FROM ATC UNTIL OUR COURSE DEV WAS NOTICED. 3) WE MAY HAVE PERCEIVED OUR CALL SIGN (IN ERROR) FOR THE CLRNC IN QUESTION; BUT WE TOOK MEASURES TO MINIMIZE ERROR BY READING BACK OUR CALL SIGN AND THE CLRNC. 4) THIS WAS A COM EVENT IN THAT A CLRNC WAS ISSUED AND AN ERROR WAS MADE IN THE ISSUANCE OF THE CORRECT CALL SIGN; OR THE INCORRECT RECEIPT OF THE CALL SIGN BY THE CREW. HOWEVER; EVEN IF THE CTLR DIDN'T CATCH THE READBACK N-NUMBER AS BEING INCORRECT; HE VERY QUICKLY NOTED THE DEV FROM THE EXPECTED COURSE AND CORRECTED IT.