Narrative:

We departed detroit for chicago, while in the climb we received numerous altitudes and frequency changes. The captain was flying, so when we received what I thought was FL230, I set it in the altitude window of the flight director. We climbed to and leveled at FL230. We changed frequencys and I checked in to cleveland center at FL230. In approximately 3 or 4 min, the controller asked our altitude and asked us to descend to FL220. I perceived that FL230 was our cleared to altitude. No member of the crew perceived otherwise. I didn't catch that FL230 was the wrong altitude for westerly flight. Also, we were filed for FL220, nor did the other crew members. I read back FL230 and the controller didn't catch it. Also, the next controller didn't catch the incorrect altitude. The captain through our union contacted cleveland center. They read back the tape which clearly indicated we had been cleared to FL220. Also, it clearly indicated that I had read back FL230. Also I checked into the next controller at FL230. No excuses. We goofed. Possible reasons. 2 early am get ups. We were tired. We had just come from chicago. Our altitude was FL230. Maybe subconsciously I was just thinking FL230. Cockpit atmosphere not as conducive as it should be as far as utilizing 3 crew members. It was my perception that the captain would rather run, do everything himself. Maybe I subconsciously wasn't quite mentally feeling as much a part of the crew as I should have. Anyway, quite a series of events. All safeguards overlooked, unheard or misheard. Believe me, this isn't going to happen to me again. I even cleaned my ears of wax. Supplemental information from acn 94262. The amount of traffic the controller handles, the speed at which clrncs are given and cockpit discipline all contributed to this error.

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Original NASA ASRS Text

Title: ACR WDB ALT DEVIATION OVERSHOT DURING CLIMB.

Narrative: WE DEPARTED DETROIT FOR CHICAGO, WHILE IN THE CLB WE RECEIVED NUMEROUS ALTS AND FREQ CHANGES. THE CAPT WAS FLYING, SO WHEN WE RECEIVED WHAT I THOUGHT WAS FL230, I SET IT IN THE ALT WINDOW OF THE FLT DIRECTOR. WE CLBED TO AND LEVELED AT FL230. WE CHANGED FREQS AND I CHKED IN TO CLEVELAND CENTER AT FL230. IN APPROX 3 OR 4 MIN, THE CTLR ASKED OUR ALT AND ASKED US TO DSND TO FL220. I PERCEIVED THAT FL230 WAS OUR CLRED TO ALT. NO MEMBER OF THE CREW PERCEIVED OTHERWISE. I DIDN'T CATCH THAT FL230 WAS THE WRONG ALT FOR WESTERLY FLT. ALSO, WE WERE FILED FOR FL220, NOR DID THE OTHER CREW MEMBERS. I READ BACK FL230 AND THE CTLR DIDN'T CATCH IT. ALSO, THE NEXT CTLR DIDN'T CATCH THE INCORRECT ALT. THE CAPT THROUGH OUR UNION CONTACTED CLEVELAND CENTER. THEY READ BACK THE TAPE WHICH CLEARLY INDICATED WE HAD BEEN CLRED TO FL220. ALSO, IT CLEARLY INDICATED THAT I HAD READ BACK FL230. ALSO I CHKED INTO THE NEXT CTLR AT FL230. NO EXCUSES. WE GOOFED. POSSIBLE REASONS. 2 EARLY AM GET UPS. WE WERE TIRED. WE HAD JUST COME FROM CHICAGO. OUR ALT WAS FL230. MAYBE SUBCONSCIOUSLY I WAS JUST THINKING FL230. COCKPIT ATMOSPHERE NOT AS CONDUCIVE AS IT SHOULD BE AS FAR AS UTILIZING 3 CREW MEMBERS. IT WAS MY PERCEPTION THAT THE CAPT WOULD RATHER RUN, DO EVERYTHING HIMSELF. MAYBE I SUBCONSCIOUSLY WASN'T QUITE MENTALLY FEELING AS MUCH A PART OF THE CREW AS I SHOULD HAVE. ANYWAY, QUITE A SERIES OF EVENTS. ALL SAFEGUARDS OVERLOOKED, UNHEARD OR MISHEARD. BELIEVE ME, THIS ISN'T GOING TO HAPPEN TO ME AGAIN. I EVEN CLEANED MY EARS OF WAX. SUPPLEMENTAL INFO FROM ACN 94262. THE AMOUNT OF TFC THE CTLR HANDLES, THE SPD AT WHICH CLRNCS ARE GIVEN AND COCKPIT DISCIPLINE ALL CONTRIBUTED TO THIS ERROR.

Data retrieved from NASA's ASRS site as of August 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.