Narrative:

Cruising at 6000 ft en route arb to ekm, autoplt engaged. IFR flight plan, but VMC conditions. Altitude hold disengaged. Aircraft climbed 500 ft before I realized the problem. I was correcting my altitude when ATC mentioned it and they issued the altimeter setting. Classic example of pilot becoming too 'kick back' with autoplt use. Lesson learned is the autoplt is a wonderful thing but it bears watching at all times!

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Original NASA ASRS Text

Title: A C335 PLT INADVERTENTLY DISCONNECTED HIS ALT HOLD, CAUSING HIM TO DEVIATE FROM HIS ALT IN AZO AIRSPACE.

Narrative: CRUISING AT 6000 FT ENRTE ARB TO EKM, AUTOPLT ENGAGED. IFR FLT PLAN, BUT VMC CONDITIONS. ALT HOLD DISENGAGED. ACFT CLBED 500 FT BEFORE I REALIZED THE PROB. I WAS CORRECTING MY ALT WHEN ATC MENTIONED IT AND THEY ISSUED THE ALTIMETER SETTING. CLASSIC EXAMPLE OF PLT BECOMING TOO 'KICK BACK' WITH AUTOPLT USE. LESSON LEARNED IS THE AUTOPLT IS A WONDERFUL THING BUT IT BEARS WATCHING AT ALL TIMES!

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.