Narrative:

I was being vectored for the approach to darlington, sc, which is the 320 degree radial from flo. I was heading 120 degrees and was descending to my assigned altitude of 7000 ft. I noticed the altimeter at 6500 ft and immediately corrected to 7000 ft. I had been using the altitude select on the autoplt and neglected to punch it for the 7000 ft descent. No comment was made by the controller.

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Original NASA ASRS Text

Title: BE20 PLT DSNDED THROUGH ASSIGNED ALT WHILE ON VECTORS FOR AN APCH. ALTDEV ALT OVERSHOT.

Narrative: I WAS BEING VECTORED FOR THE APCH TO DARLINGTON, SC, WHICH IS THE 320 DEG RADIAL FROM FLO. I WAS HEADING 120 DEGS AND WAS DSNDING TO MY ASSIGNED ALT OF 7000 FT. I NOTICED THE ALTIMETER AT 6500 FT AND IMMEDIATELY CORRECTED TO 7000 FT. I HAD BEEN USING THE ALT SELECT ON THE AUTOPLT AND NEGLECTED TO PUNCH IT FOR THE 7000 FT DSCNT. NO COMMENT WAS MADE BY THE CTLR.

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.