Narrative:

On the night of nov/mon/04, aircraft X was in cruise flight south of billings, mt. I had told the captain that I was off of the #1 radio and he had center. While I was retrieving the ATIS for our arrival into bil, ZLC issued a descent clearance at our discretion. I checked back with the captain and asked '13?' thirteen thousand ft is our normal descent clearance issued to arriving traffic at bil. The captain stated 'discretion to 31.' I then set in FL310 in the altitude alerter. The captain had already started the aircraft down with the autoplt. The aircraft was at FL320 and descending when ZLC called and issued an immediate climb to FL330 and a traffic alert. The captain immediately started a climb and I called center and told them we were in the climb to FL330 but had been issued FL310. The controller replied negative, that we had only been issued a pilot's discretion descent to FL330. Center told us we had to be level at FL330 in 1 min. Center called back, the aircraft was at FL329 and climbing and center 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 handoff to bil approach, I asked center if we needed to give him a call when we got on the ground. 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 descent and the captain should have told me the correct altitude or even put it in the altitude alerter himself.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 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.