Narrative:

During departure from cos, contacted ZDV. Climb clearance was 16000 ft. ZDV issued a climb clearance on course to FL200. I read back FL200, but the first officer understood and set FL220 in the altitude alert window. We then both acknowledged the clearance incorrectly as climb and maintain FL220. Leaving FL200, ZDV reported traffic(flight of 2 F-15's) north at 12 - 1 O'clock position. We both saw and acknowledged the 2 aircraft. Leaving FL210, we received a TA, and noted the traffic at 12 O'clock, passing right to left -- their range about 10 NM. At FL215, we received an RA, followed immediately by a clear of conflict message. We observed the flight at 11-12 O'clock position, moving right to left, but did not consider them a collision risk at any time. At that time, we were queried by ZDV to confirm altitude as FL200. I stated that I had read back FL220 as our clearance limit. This statement was later proven incorrect, upon review of tapes. Contributing factors include fatigue from minimum crew rest, preceded by a 6 hour flight day which included mechanical irregularities and deicing delays. Another factor was the fact that we had the traffic in sight at all times, did not consider it a risk to our route of flight, and failed to consider altitude deviation as a potential problem. Contributing was our past experience of receiving TA's and RA's during flight at altitude as well as in terminal areas, where altitude deviations were not a factor. The TA/RA alert simply did not clue us into the fact that we had (possibly) exceeded a clearance limit. Loss of separation caused den to file a report on the incident.

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Original NASA ASRS Text

Title: ACR PIC TALKED OUT OF ALT READBACK OF FL200 AS FO INPUTS FL220 IN ALT ALERTER.

Narrative: DURING DEP FROM COS, CONTACTED ZDV. CLB CLRNC WAS 16000 FT. ZDV ISSUED A CLB CLRNC ON COURSE TO FL200. I READ BACK FL200, BUT THE FO UNDERSTOOD AND SET FL220 IN THE ALT ALERT WINDOW. WE THEN BOTH ACKNOWLEDGED THE CLRNC INCORRECTLY AS CLB AND MAINTAIN FL220. LEAVING FL200, ZDV RPTED TFC(FLT OF 2 F-15'S) N AT 12 - 1 O'CLOCK POS. WE BOTH SAW AND ACKNOWLEDGED THE 2 ACFT. LEAVING FL210, WE RECEIVED A TA, AND NOTED THE TFC AT 12 O'CLOCK, PASSING R TO L -- THEIR RANGE ABOUT 10 NM. AT FL215, WE RECEIVED AN RA, FOLLOWED IMMEDIATELY BY A CLR OF CONFLICT MESSAGE. WE OBSERVED THE FLT AT 11-12 O'CLOCK POS, MOVING R TO L, BUT DID NOT CONSIDER THEM A COLLISION RISK AT ANY TIME. AT THAT TIME, WE WERE QUERIED BY ZDV TO CONFIRM ALT AS FL200. I STATED THAT I HAD READ BACK FL220 AS OUR CLRNC LIMIT. THIS STATEMENT WAS LATER PROVEN INCORRECT, UPON REVIEW OF TAPES. CONTRIBUTING FACTORS INCLUDE FATIGUE FROM MINIMUM CREW REST, PRECEDED BY A 6 HR FLT DAY WHICH INCLUDED MECHANICAL IRREGULARITIES AND DEICING DELAYS. ANOTHER FACTOR WAS THE FACT THAT WE HAD THE TFC IN SIGHT AT ALL TIMES, DID NOT CONSIDER IT A RISK TO OUR RTE OF FLT, AND FAILED TO CONSIDER ALT DEV AS A POTENTIAL PROB. CONTRIBUTING WAS OUR PAST EXPERIENCE OF RECEIVING TA'S AND RA'S DURING FLT AT ALT AS WELL AS IN TERMINAL AREAS, WHERE ALT DEVS WERE NOT A FACTOR. THE TA/RA ALERT SIMPLY DID NOT CLUE US INTO THE FACT THAT WE HAD (POSSIBLY) EXCEEDED A CLRNC LIMIT. LOSS OF SEPARATION CAUSED DEN TO FILE A RPT ON THE INCIDENT.

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.