Narrative:

I was on VOR airways when en route to C09 from 3AR. Chicago approach cleared me down to 2500 until intercepting inbound course. This altitude put me in the middle of a cloud layer where some icing had been reported further north. While in the layer I received a series of radar vectors and was cleared for the approach upon intercepting inbound. The controller advised me I was now 4 north of the VOR and was to contact him to cancel IFR when able. Due to the radar vectors I was temporarily disoriented and began to think I was south of the VOR and began my descent since 4 DME was the FAF. As I was descending I began to question myself and discovered I had not passed the VOR. I pulled up immediately but I had descended just below 2000 MSL by that time. Approach gave no warning of descending below the min approach altitude. Once I realized what I had done, the rest of the approach was flown with much more care and attentiveness. Factors causing occurrence: I would say the off airway vectors combined with the fact that I hadn't done a lot of recent IFR flying. Furthermore it was an area I was unfamiliar with. Also I was the only pilot and I have been trained for 2 pilot operations. I might have been relying on the back up of other pilots in previous flts.

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Original NASA ASRS Text

Title: GA SMA ALTDEV DSNDED BELOW FAF ALT BEFORE REACHING THE FAF.

Narrative: I WAS ON VOR AIRWAYS WHEN ENRTE TO C09 FROM 3AR. CHICAGO APCH CLRED ME DOWN TO 2500 UNTIL INTERCEPTING INBOUND COURSE. THIS ALT PUT ME IN THE MIDDLE OF A CLOUD LAYER WHERE SOME ICING HAD BEEN RPTED FURTHER N. WHILE IN THE LAYER I RECEIVED A SERIES OF RADAR VECTORS AND WAS CLRED FOR THE APCH UPON INTERCEPTING INBOUND. THE CTLR ADVISED ME I WAS NOW 4 N OF THE VOR AND WAS TO CONTACT HIM TO CANCEL IFR WHEN ABLE. DUE TO THE RADAR VECTORS I WAS TEMPORARILY DISORIENTED AND BEGAN TO THINK I WAS S OF THE VOR AND BEGAN MY DSCNT SINCE 4 DME WAS THE FAF. AS I WAS DSNDING I BEGAN TO QUESTION MYSELF AND DISCOVERED I HAD NOT PASSED THE VOR. I PULLED UP IMMEDIATELY BUT I HAD DSNDED JUST BELOW 2000 MSL BY THAT TIME. APCH GAVE NO WARNING OF DSNDING BELOW THE MIN APCH ALT. ONCE I REALIZED WHAT I HAD DONE, THE REST OF THE APCH WAS FLOWN WITH MUCH MORE CARE AND ATTENTIVENESS. FACTORS CAUSING OCCURRENCE: I WOULD SAY THE OFF AIRWAY VECTORS COMBINED WITH THE FACT THAT I HADN'T DONE A LOT OF RECENT IFR FLYING. FURTHERMORE IT WAS AN AREA I WAS UNFAMILIAR WITH. ALSO I WAS THE ONLY PLT AND I HAVE BEEN TRAINED FOR 2 PLT OPS. I MIGHT HAVE BEEN RELYING ON THE BACK UP OF OTHER PLTS IN PREVIOUS FLTS.

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.