Narrative:

We were cleared down to 12000 ft about 20 mi from air VOR. Upon reaching 14000 ft and about 5 mi from fix, controller called us and gave holding instructions to the captain (PNF). We were about to go over the fix and while receiving the clearance I disengaged the autoplt receiving the aural warning (autoplt). I didn't hear the clearance altitude and the captain didn't put the new altitude in the alerter, because he was trying to get the hold in the FMS. The new altitude was 13000 ft. He (captain) never called the altitude and I descended to 12700 ft. The controller asked our altitude and the captain then alerted me to the clearance altitude and I pulled up and had the aircraft at 13000 ft by the end of his transmission. The late clearance (holding) was the primary contributing factor to the incident. I (PF) didn't hear the complete clearance due to the aural warning and the captain made the decision that horizontal situational awareness was more crucial than vertical. I was trying to fly the hold while putting in the VOR frequency not paying attention to the altitude (new) cleared to in the hold. The recent 12000 ft clearance was received so close to the holding clearance I didn't question the altitude.

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Original NASA ASRS Text

Title: AN E145 CREW OVERSHOT ASSIGNED ALT DSNDING INTO PIT.

Narrative: WE WERE CLRED DOWN TO 12000 FT ABOUT 20 MI FROM AIR VOR. UPON REACHING 14000 FT AND ABOUT 5 MI FROM FIX, CTLR CALLED US AND GAVE HOLDING INSTRUCTIONS TO THE CAPT (PNF). WE WERE ABOUT TO GO OVER THE FIX AND WHILE RECEIVING THE CLRNC I DISENGAGED THE AUTOPLT RECEIVING THE AURAL WARNING (AUTOPLT). I DIDN'T HEAR THE CLRNC ALT AND THE CAPT DIDN'T PUT THE NEW ALT IN THE ALERTER, BECAUSE HE WAS TRYING TO GET THE HOLD IN THE FMS. THE NEW ALT WAS 13000 FT. HE (CAPT) NEVER CALLED THE ALT AND I DSNDED TO 12700 FT. THE CTLR ASKED OUR ALT AND THE CAPT THEN ALERTED ME TO THE CLRNC ALT AND I PULLED UP AND HAD THE ACFT AT 13000 FT BY THE END OF HIS XMISSION. THE LATE CLRNC (HOLDING) WAS THE PRIMARY CONTRIBUTING FACTOR TO THE INCIDENT. I (PF) DIDN'T HEAR THE COMPLETE CLRNC DUE TO THE AURAL WARNING AND THE CAPT MADE THE DECISION THAT HORIZ SITUATIONAL AWARENESS WAS MORE CRUCIAL THAN VERT. I WAS TRYING TO FLY THE HOLD WHILE PUTTING IN THE VOR FREQ NOT PAYING ATTN TO THE ALT (NEW) CLRED TO IN THE HOLD. THE RECENT 12000 FT CLRNC WAS RECEIVED SO CLOSE TO THE HOLDING CLRNC I DIDN'T QUESTION THE ALT.

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.