Narrative:

We were inbound to denver on the powdr arrival, and had been handed off to den approach. The captain checked in, and I believe at that time we were cleared to 13000 ft from 16000 ft. I didn't hear the clearance, but don't recall what might have distraction me. The captain later told me that we were cleared down to 13000 ft and I began the descent. Nothing was said by the controller at that time. The chief pilot called me the following day and said that the TRACON had called and stated that: 1) an aircraft ('commander') had been cleared from 17000 ft to 16000 ft after we read back our clearance. 2) we began our descent 2 mins after receiving our clearance. 3) separation was lost (no details on how close we were). 4) the controller would take the blame because he should have waited until he saw us leave 16000 ft before descending the second aircraft. Contributing factors: 1) I had started work after a few days off, but hadn't slept well before the early (XA15) show. 2) company doesn't have established policy like other carriers to have the PF verify altitude assignments after the PNF sets them in the altitude alerter. Note: the chief pilot claimed the incident as reported by the TRACON occurred on the northwest arrival (tomsn?) on an earlier flight, but my recollection was that it occurred on the above stated arrival and time of day.

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Original NASA ASRS Text

Title: AN ACR BE02 WAS SLOW TO DSND FROM 16000 FT AND THE APCH CTLR CLRED ANOTHER ACFT TO THAT ALT BEFORE LEGAL SEPARATION EXISTED. THE TRACON NOTIFIED THE ACR CHIEF PLT OF THE INCIDENT AND INFORMED HIM THAT THE CTLR WAS CHARGED WITH AN ERROR BECAUSE OF THE SLOW DSCNT OF THE BE02. RPTR GAVE MANY EXCUSES FOR HIS SLOW REACTION TO THE DSCNT CLRNC.

Narrative: WE WERE INBOUND TO DENVER ON THE POWDR ARR, AND HAD BEEN HANDED OFF TO DEN APCH. THE CAPT CHKED IN, AND I BELIEVE AT THAT TIME WE WERE CLRED TO 13000 FT FROM 16000 FT. I DIDN'T HEAR THE CLRNC, BUT DON'T RECALL WHAT MIGHT HAVE DISTR ME. THE CAPT LATER TOLD ME THAT WE WERE CLRED DOWN TO 13000 FT AND I BEGAN THE DSCNT. NOTHING WAS SAID BY THE CTLR AT THAT TIME. THE CHIEF PLT CALLED ME THE FOLLOWING DAY AND SAID THAT THE TRACON HAD CALLED AND STATED THAT: 1) AN ACFT ('COMMANDER') HAD BEEN CLRED FROM 17000 FT TO 16000 FT AFTER WE READ BACK OUR CLRNC. 2) WE BEGAN OUR DSCNT 2 MINS AFTER RECEIVING OUR CLRNC. 3) SEPARATION WAS LOST (NO DETAILS ON HOW CLOSE WE WERE). 4) THE CTLR WOULD TAKE THE BLAME BECAUSE HE SHOULD HAVE WAITED UNTIL HE SAW US LEAVE 16000 FT BEFORE DSNDING THE SECOND ACFT. CONTRIBUTING FACTORS: 1) I HAD STARTED WORK AFTER A FEW DAYS OFF, BUT HADN'T SLEPT WELL BEFORE THE EARLY (XA15) SHOW. 2) COMPANY DOESN'T HAVE ESTABLISHED POLICY LIKE OTHER CARRIERS TO HAVE THE PF VERIFY ALT ASSIGNMENTS AFTER THE PNF SETS THEM IN THE ALT ALERTER. NOTE: THE CHIEF PLT CLAIMED THE INCIDENT AS RPTED BY THE TRACON OCCURRED ON THE NW ARR (TOMSN?) ON AN EARLIER FLT, BUT MY RECOLLECTION WAS THAT IT OCCURRED ON THE ABOVE STATED ARR AND TIME OF DAY.

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.