Narrative:

Failed to change altimeter to standard (29.92) leaving FL180 resulting in a leveloff altitude of FL283 (300 ft high). Was advised by ATC, corrected and descended to FL280.

Google
 

Original NASA ASRS Text

Title: FLC OF AN MLG FORGOT TO RESET THEIR ALTIMETERS PASSING THROUGH FL180 RESULTING IN LEVELOFF ON AN ALT 300 FT HIGHER THAN ASSIGNED. ATC INTERVENED AND ALERTED THEM OF THEIR ACTUAL ALT READOUT.

Narrative: FAILED TO CHANGE ALTIMETER TO STANDARD (29.92) LEAVING FL180 RESULTING IN A LEVELOFF ALT OF FL283 (300 FT HIGH). WAS ADVISED BY ATC, CORRECTED AND DSNDED TO FL280.

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.