Narrative:

We departed avp for a flight to phl. After our handoff to ZNY we were cleared direct east texas, climb and maintain 12000 ft. We read the clearance back and using altitude awareness procedures set and crosschecked the altitude. At 11300 ft ATC asked our altitude and we said 'leaving 11500 ft for 12000 ft.' ATC said our clearance altitude was 11000 ft and to descend. We descended to 11000 ft and no conflict was reported. We continued to phl.

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Original NASA ASRS Text

Title: A B737-200 FLC CLBS TO THE WRONG ALT, 12000 FT VERSUS 11000 FT, AFTER CLRNC READ BACK TO ZNY.

Narrative: WE DEPARTED AVP FOR A FLT TO PHL. AFTER OUR HDOF TO ZNY WE WERE CLRED DIRECT EAST TEXAS, CLB AND MAINTAIN 12000 FT. WE READ THE CLRNC BACK AND USING ALT AWARENESS PROCS SET AND XCHKED THE ALT. AT 11300 FT ATC ASKED OUR ALT AND WE SAID 'LEAVING 11500 FT FOR 12000 FT.' ATC SAID OUR CLRNC ALT WAS 11000 FT AND TO DSND. WE DSNDED TO 11000 FT AND NO CONFLICT WAS RPTED. WE CONTINUED TO PHL.

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.