Narrative:

I engaged the autoplt approaching our assigned altitude. The airplane continued climbing about 350 ft above assigned altitude. I physically flew the airplane back to altitude. ATC called to 'check your altitude.' I should have checked the mode annunciation panel to verify autoplt engagement.

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Original NASA ASRS Text

Title: ALTDEV AS A DEP B737 PIC OVERSHOOTS HIS ASSIGNED ALT AFTER NOT INSURING THAT THE AUTOPLT WAS ENGAGED NEAR MDW, IL.

Narrative: I ENGAGED THE AUTOPLT APCHING OUR ASSIGNED ALT. THE AIRPLANE CONTINUED CLBING ABOUT 350 FT ABOVE ASSIGNED ALT. I PHYSICALLY FLEW THE AIRPLANE BACK TO ALT. ATC CALLED TO 'CHK YOUR ALT.' I SHOULD HAVE CHKED THE MODE ANNUNCIATION PANEL TO VERIFY AUTOPLT ENGAGEMENT.

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.