POTENTIAL CONFLICT OCCURS WHEN A WW24 PIC MISINTERPS THE AMENDED ALT CLRNC GIVEN TO FLT WHILE FO IS OFF FREQ.

Narrative

ON THE NIGHT OF NOV/MON/04; ACFT X WAS IN CRUISE FLT S OF BILLINGS; MT. I HAD TOLD THE CAPT THAT I WAS OFF OF THE #1 RADIO AND HE HAD CTR. WHILE I WAS RETRIEVING THE ATIS FOR OUR ARR INTO BIL; ZLC ISSUED A DSCNT CLRNC AT OUR DISCRETION. I CHKED BACK WITH THE CAPT AND ASKED '13?' THIRTEEN THOUSAND FT IS OUR NORMAL DSCNT CLRNC ISSUED TO ARRIVING TFC AT BIL. THE CAPT STATED 'DISCRETION TO 31.' I THEN SET IN FL310 IN THE ALT ALERTER. THE CAPT HAD ALREADY STARTED THE ACFT DOWN WITH THE AUTOPLT. THE ACFT WAS AT FL320 AND DSNDING WHEN ZLC CALLED AND ISSUED AN IMMEDIATE CLB TO FL330 AND A TFC ALERT. THE CAPT IMMEDIATELY STARTED A CLB AND I CALLED CTR AND TOLD THEM WE WERE IN THE CLB TO FL330 BUT HAD BEEN ISSUED FL310. THE CTLR REPLIED NEGATIVE; THAT WE HAD ONLY BEEN ISSUED A PLT'S DISCRETION DSCNT TO FL330. CTR TOLD US WE HAD TO BE LEVEL AT FL330 IN 1 MIN. CTR CALLED BACK; THE ACFT WAS AT FL329 AND CLBING AND CTR SAID WE HAD TO BE LEVEL IN 10 SECONDS; WHICH WE WERE. AN MD80 PASSED UNDERNEATH US AT FL310. ABOUT 5 MINS LATER; PRIOR TO THE HDOF TO BIL APCH; I ASKED CTR IF WE NEEDED TO GIVE HIM A CALL WHEN WE GOT ON THE GND. HE SAID THAT WAS NOT NECESSARY; BUT I REQUESTED THE TELEPHONE NUMBER ANYWAY. MY CONCLUSION: I SHOULD NOT HAVE BEEN GETTING THE ATIS AT THE TOP OF THE DSCNT AND THE CAPT SHOULD HAVE TOLD ME THE CORRECT ALT OR EVEN PUT IT IN THE ALT ALERTER HIMSELF.