Narrative:

On sep/fri/03, I was flying a debonair IFR from ggi to pkd. Cruising at 8000 ft there was a solid cloud layer in the area of pkd with tops reported at 6500 ft. The pkd ASOS reported ceiling at 3300 ft which would put the bottom of the layer at 4700 ft MSL. I was cleared down to 5000 ft by ZMA, which put me in the clouds. About 20 mi out I was cleared to 3500 ft. I punched off altitude hold, began the descent and set up the approach on the GPS. Knowing I would break out before reaching 3500 ft I monitored descent rate while organizing the cockpit and panel. ATC asked if I could do a visual approach into pkd and I responded, based on the ASOS ceiling report, that yes, I should be able to do the visual. Just as I broke out of the clouds, and ATC called and said radar contact was lost. It was then I glanced at the altimeter and discovered I was at 3000 ft 500 ft below the assigned altitude. (The ceiling was actually 2000 ft AGL or about 3400 ft MSL.) I apologized that I had gone so low. ATC told me to climb back to 3500 ft and report established on an approach to pkd. However, I had the airport in sight and knew there was another aircraft behind me en route to pkd. Rather than climb back into IMC and maneuver to get on an approach, I canceled IFR and proceeded straight in to runway 31 at pkd. Lessons learned -- monitor altimeter closer -- don't get distraction by cockpit chores, ASOS may be accurate but only above the airport. I chose to cancel and go straight to airport to avoid delays or conflicts with other aircraft which would have made this mistake worse.

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Original NASA ASRS Text

Title: DEBONAIR PLT OVERSHOOTS HIS ALT IN DSCNT WHILE IMC INTO VMC CONDITIONS, A NEAR CFTT, 18 MI SE OF PKD, MN.

Narrative: ON SEP/FRI/03, I WAS FLYING A DEBONAIR IFR FROM GGI TO PKD. CRUISING AT 8000 FT THERE WAS A SOLID CLOUD LAYER IN THE AREA OF PKD WITH TOPS RPTED AT 6500 FT. THE PKD ASOS RPTED CEILING AT 3300 FT WHICH WOULD PUT THE BOTTOM OF THE LAYER AT 4700 FT MSL. I WAS CLRED DOWN TO 5000 FT BY ZMA, WHICH PUT ME IN THE CLOUDS. ABOUT 20 MI OUT I WAS CLRED TO 3500 FT. I PUNCHED OFF ALT HOLD, BEGAN THE DSCNT AND SET UP THE APCH ON THE GPS. KNOWING I WOULD BREAK OUT BEFORE REACHING 3500 FT I MONITORED DSCNT RATE WHILE ORGANIZING THE COCKPIT AND PANEL. ATC ASKED IF I COULD DO A VISUAL APCH INTO PKD AND I RESPONDED, BASED ON THE ASOS CEILING RPT, THAT YES, I SHOULD BE ABLE TO DO THE VISUAL. JUST AS I BROKE OUT OF THE CLOUDS, AND ATC CALLED AND SAID RADAR CONTACT WAS LOST. IT WAS THEN I GLANCED AT THE ALTIMETER AND DISCOVERED I WAS AT 3000 FT 500 FT BELOW THE ASSIGNED ALT. (THE CEILING WAS ACTUALLY 2000 FT AGL OR ABOUT 3400 FT MSL.) I APOLOGIZED THAT I HAD GONE SO LOW. ATC TOLD ME TO CLB BACK TO 3500 FT AND RPT ESTABLISHED ON AN APCH TO PKD. HOWEVER, I HAD THE ARPT IN SIGHT AND KNEW THERE WAS ANOTHER ACFT BEHIND ME ENRTE TO PKD. RATHER THAN CLB BACK INTO IMC AND MANEUVER TO GET ON AN APCH, I CANCELED IFR AND PROCEEDED STRAIGHT IN TO RWY 31 AT PKD. LESSONS LEARNED -- MONITOR ALTIMETER CLOSER -- DON'T GET DISTR BY COCKPIT CHORES, ASOS MAY BE ACCURATE BUT ONLY ABOVE THE ARPT. I CHOSE TO CANCEL AND GO STRAIGHT TO ARPT TO AVOID DELAYS OR CONFLICTS WITH OTHER ACFT WHICH WOULD HAVE MADE THIS MISTAKE WORSE.

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.