Narrative:

During climb out, FL230 was assigned, then modified to FL200 while passing through 18000 ft MSL. Autoplt was in use. After normal leveloff at FL200, ATC noted that altitude readout was FL204. We then noted that captain's standby altimeter (which is controling) had not been reset to 29.92. Altimeter was reset and ATC seemed to accept explanation. There were no other aircraft nearby and apparently no conflict occurred.

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Original NASA ASRS Text

Title: CAPT OF ACR WDB ACFT OVERSHOT CLB ALT RESTRICTION DUE TO FAILURE TO RESET ALT AT FL180.

Narrative: DURING CLBOUT, FL230 WAS ASSIGNED, THEN MODIFIED TO FL200 WHILE PASSING THROUGH 18000 FT MSL. AUTOPLT WAS IN USE. AFTER NORMAL LEVELOFF AT FL200, ATC NOTED THAT ALT READOUT WAS FL204. WE THEN NOTED THAT CAPT'S STANDBY ALTIMETER (WHICH IS CTLING) HAD NOT BEEN RESET TO 29.92. ALTIMETER WAS RESET AND ATC SEEMED TO ACCEPT EXPLANATION. THERE WERE NO OTHER ACFT NEARBY AND APPARENTLY NO CONFLICT OCCURRED.

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.