Narrative:

After reaching cruise altitude at FL330 center asked us to confirm our altitude. I reported level at FL330 which was rogered by the controller with the comment that he read our altitude as 300 ft low. It was then that I discovered that I had not reset my altimeter climbing through FL180. I corrected the setting. The first officer was flying the leg and he had reset his altimeter but since he had switched digital flight guidance computer to #1 to couple the autoplt to the navigation the airplane was flying was my setting. He had not yet noticed the fact that I had not reset my altimeter settings. I do not know how I missed the transition and how I lost checklist discipline but that was the cause of this incident. I cannot remember a distraction but there must have been one. I must reaffirm my checklist discipline.

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Original NASA ASRS Text

Title: MLG FLC FAILS TO SET ALTIMETER PASSING FL180, ALTDEV.

Narrative: AFTER REACHING CRUISE ALT AT FL330 CTR ASKED US TO CONFIRM OUR ALT. I RPTED LEVEL AT FL330 WHICH WAS ROGERED BY THE CTLR WITH THE COMMENT THAT HE READ OUR ALT AS 300 FT LOW. IT WAS THEN THAT I DISCOVERED THAT I HAD NOT RESET MY ALTIMETER CLBING THROUGH FL180. I CORRECTED THE SETTING. THE FO WAS FLYING THE LEG AND HE HAD RESET HIS ALTIMETER BUT SINCE HE HAD SWITCHED DIGITAL FLT GUIDANCE COMPUTER TO #1 TO COUPLE THE AUTOPLT TO THE NAV THE AIRPLANE WAS FLYING WAS MY SETTING. HE HAD NOT YET NOTICED THE FACT THAT I HAD NOT RESET MY ALTIMETER SETTINGS. I DO NOT KNOW HOW I MISSED THE TRANSITION AND HOW I LOST CHKLIST DISCIPLINE BUT THAT WAS THE CAUSE OF THIS INCIDENT. I CANNOT REMEMBER A DISTR BUT THERE MUST HAVE BEEN ONE. I MUST REAFFIRM MY CHKLIST DISCIPLINE.

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.