Narrative:

En route to lax from mry, we were cleared to FL230 (climbing). At about 23500 ft, the center controller alerted us that we were climbing through our assigned altitude. The first officer (PF) immediately disconnected the autoplt and descended to 23000 ft. All told, we had climbed 800 ft above our assigned altitude. Even though the autoplt was engaged, I noticed that the first officer had not selected the altitude capture function. I believe the reason we did not catch this error was because we were both preoccupied with other tasks. The first officer was looking out his side window and commenting on how beautiful the sunset was, and I was reading the QRH manual, preparing for an upcoming simulator check ride. In the future, I plan to do my studying on the ground, and pay more attention to my copilot's autoplt panel.

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Original NASA ASRS Text

Title: AN EMB120 FLT CREW CLBS ABOVE THEIR ASSIGNED CRUISE ALT WHEN THE ALT AUTO CAPTURE IS NOT ENGAGED FOR LEVELOFF 40 MI S OF MRY, CA.

Narrative: ENRTE TO LAX FROM MRY, WE WERE CLRED TO FL230 (CLBING). AT ABOUT 23500 FT, THE CTR CTLR ALERTED US THAT WE WERE CLBING THROUGH OUR ASSIGNED ALT. THE FO (PF) IMMEDIATELY DISCONNECTED THE AUTOPLT AND DSNDED TO 23000 FT. ALL TOLD, WE HAD CLBED 800 FT ABOVE OUR ASSIGNED ALT. EVEN THOUGH THE AUTOPLT WAS ENGAGED, I NOTICED THAT THE FO HAD NOT SELECTED THE ALT CAPTURE FUNCTION. I BELIEVE THE REASON WE DID NOT CATCH THIS ERROR WAS BECAUSE WE WERE BOTH PREOCCUPIED WITH OTHER TASKS. THE FO WAS LOOKING OUT HIS SIDE WINDOW AND COMMENTING ON HOW BEAUTIFUL THE SUNSET WAS, AND I WAS READING THE QRH MANUAL, PREPARING FOR AN UPCOMING SIMULATOR CHK RIDE. IN THE FUTURE, I PLAN TO DO MY STUDYING ON THE GND, AND PAY MORE ATTN TO MY COPLT'S AUTOPLT PANEL.

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.