Narrative:

While approaching acy or vcn VOR from the northeast, we were given a descent to 4000 ft MSL. Passing/descending through 3750 ft, I disengaged the autoplt and climbed to 4000 ft. The altitude deviation may have hit 300 ft. The autoplt/flight director was in 'pitch' mode instead of 'altitude select.' 4000 ft was set in the altitude select window. Both pilots thought 'altitude select' was selected and did not know why the flight director was in 'pitch' mode. System worked ok for remainder of flight. Lesson: check, check, and rechk and verify with other pilot/center.

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Original NASA ASRS Text

Title: A DASH 8 FLC DSNDED BELOW THE ASSIGNED ALT NEAR VCN.

Narrative: WHILE APCHING ACY OR VCN VOR FROM THE NE, WE WERE GIVEN A DSCNT TO 4000 FT MSL. PASSING/DSNDING THROUGH 3750 FT, I DISENGAGED THE AUTOPLT AND CLBED TO 4000 FT. THE ALTDEV MAY HAVE HIT 300 FT. THE AUTOPLT/FLT DIRECTOR WAS IN 'PITCH' MODE INSTEAD OF 'ALT SELECT.' 4000 FT WAS SET IN THE ALT SELECT WINDOW. BOTH PLTS THOUGHT 'ALT SELECT' WAS SELECTED AND DID NOT KNOW WHY THE FLT DIRECTOR WAS IN 'PITCH' MODE. SYS WORKED OK FOR REMAINDER OF FLT. LESSON: CHK, CHK, AND RECHK AND VERIFY WITH OTHER PLT/CTR.

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.