Narrative:

Our aircraft was level at FL180 on the brush 2 arrival to stl. ZKC cleared us to 'cross oddly at 8000' and provided stl altimeter. I copied clearance onto my note pad and read it back. Began discussion with first officer (PF) about calculations for making the crossing restriction considering our ground speed expected in descent. We calculated the distance required to lose 10000 ft, and he elected to remain at FL180 until 5 mi from that distance. Shortly, the first officer announced leaving FL180, and I reported vacating to center, and dialed the altitude alerter to 10000, apparently preoccupied with having 10000 ft to lose. Aircraft leveled at 10000 and was handed off to stl approach. We did not realize our error until stl approach questioned our clearance. There was apparently no separation compromise, as stl approach simply provided descent and vectors for approach. This was our 6TH day on duty. Also, I did not set the altitude selector when the clearance was received as we did not intend to descend immediately, and I had been told by FAA inspector that to do so was deactivating the aircraft warning device and therefore a violation. Had I done so, the clearance would have been fresh, the selector properly set and the deviation would not have occurred. Callback conversation with reporter revealed the following information: when inspector informed me that changing my altitude selector before starting down to a new assigned altitude was a violation he was quite firm in his opinion and I did not quarrel with him about it.

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Original NASA ASRS Text

Title: FLC OF COMMUTER CLRED TO 8000 MSL LEVELED AT 10000 MSL.

Narrative: OUR ACFT WAS LEVEL AT FL180 ON THE BRUSH 2 ARR TO STL. ZKC CLRED US TO 'CROSS ODDLY AT 8000' AND PROVIDED STL ALTIMETER. I COPIED CLRNC ONTO MY NOTE PAD AND READ IT BACK. BEGAN DISCUSSION WITH FO (PF) ABOUT CALCULATIONS FOR MAKING THE XING RESTRICTION CONSIDERING OUR GND SPD EXPECTED IN DSCNT. WE CALCULATED THE DISTANCE REQUIRED TO LOSE 10000 FT, AND HE ELECTED TO REMAIN AT FL180 UNTIL 5 MI FROM THAT DISTANCE. SHORTLY, THE FO ANNOUNCED LEAVING FL180, AND I RPTED VACATING TO CENTER, AND DIALED THE ALT ALERTER TO 10000, APPARENTLY PREOCCUPIED WITH HAVING 10000 FT TO LOSE. ACFT LEVELED AT 10000 AND WAS HANDED OFF TO STL APCH. WE DID NOT REALIZE OUR ERROR UNTIL STL APCH QUESTIONED OUR CLRNC. THERE WAS APPARENTLY NO SEPARATION COMPROMISE, AS STL APCH SIMPLY PROVIDED DSCNT AND VECTORS FOR APCH. THIS WAS OUR 6TH DAY ON DUTY. ALSO, I DID NOT SET THE ALT SELECTOR WHEN THE CLRNC WAS RECEIVED AS WE DID NOT INTEND TO DSND IMMEDIATELY, AND I HAD BEEN TOLD BY FAA INSPECTOR THAT TO DO SO WAS DEACTIVATING THE ACFT WARNING DEVICE AND THEREFORE A VIOLATION. HAD I DONE SO, THE CLRNC WOULD HAVE BEEN FRESH, THE SELECTOR PROPERLY SET AND THE DEV WOULD NOT HAVE OCCURRED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: WHEN INSPECTOR INFORMED ME THAT CHANGING MY ALT SELECTOR BEFORE STARTING DOWN TO A NEW ASSIGNED ALT WAS A VIOLATION HE WAS QUITE FIRM IN HIS OPINION AND I DID NOT QUARREL WITH HIM ABOUT IT.

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.