IN THE MIDDLE OF A BRIEFING B727 CREW TOOK A CLRNC WITHOUT HEARING THE CALL SIGN. FOREIGN CTLR ALSO DID NOT CATCH THE WRONG CALL SIGN IN THE READBACK AND ACCEPTED IT UNTIL HE DISCOVERED WRONG ACFT DSNDING.

Narrative

WE WERE CRUISING AT FL180 ENRTE TO LFPG. CREW WAS PREPARING FOR APCH TO RWY 9 AT LFPG. CAPT HAD COMMENCED APCH BRIEFING WHEN FO HEARD A RADIO CALL FROM PARIS CTL. FO DID NOT HEAR CALL SIGN DUE TO CAPT'S APCH BRIEFING. CTLR'S INSTRUCTIONS WERE FOR SOMEONE TO DSND TO FL160 AND MAINTAIN 280 KTS IN DSCNT. FO READ BACK INSTRUCTION WITH OUR CALL SIGN. CTLR ACKNOWLEDGED READBACK. CAPT BEGAN DSCNT TO FL160. PASSING FL160; PARIS CTL ASKED US WHY WE HAD LEFT FL180. FO REPLIED WE HAD BEEN CLRED TO FL160. CTLR STATED THAT CLRNC HAD BEEN FOR ANOTHER ACFT. WE WERE TOLD TO MAINTAIN FL160. RECOMMEND CREWS VERIFY CLRNC IS FOR THEM. SUPPLEMENTAL INFO FROM ACN 468844: WHILE ALL STANDARD CHALLENGES AND REPLIES DID TAKE PLACE IN THE COCKPIT BTWN THE FLC MEMBERS PRIOR TO DSCNT; THERE MAY HAVE BEEN SOME BREAKDOWN IN COM BECAUSE THE CAPT WAS CONDUCTING AN APCH BRIEFING WHEN THE RADIO XMISSIONS OCCURRED INITIALLY BTWN THE FO AND CTR CTLR. ALSO; BECAUSE THE FO READ BACK A CLRNC TO FL160 PRIOR TO DSCNT (WITH NO CORRECTION FROM CTR); WE ASSUMED THE CLRNC HAD BEEN FOR US (NOT ANOTHER ACFT). THE CONTRIBUTING FACTOR IN THIS EVENT WAS A BREAKDOWN IN COM BTWN OUR ACFT AND THE CTR CTLR.