What happened
After receiving a weather briefing, the pilot filed an IFR flight plan for a flight to Casa De Aero Airport in Hampshire, Illinois. During pre-flight communications, an Air Traffic Control Specialist inquired if the pilot had reviewed the AIRMETs regarding turbulence and IFR conditions along the route; the pilot acknowledged the presence of turbulence, icing, and IFR conditions.
While en route, the pilot contacted the Kankakee, Illinois, Flight Service Station (FSS) to request weather updates. The FSS reported that DuPage County Airport in West Chicago, Illinois, had an overcast ceiling of 400 feet AGL, 5 miles visibility, mist, and a temperature and dew point of 1 degree Celsius. The pilot also requested weather for Madison, Wisconsin, which was reported as having a broken ceiling of 800 feet AGL, 1.5 mile visibility with light freezing drizzle, and a temperature of minus 1 degree Celsius.
The pilot subsequently checked in with Chicago TRACON, reporting a level of 4,000 feet MSL. At 1838, the controller cleared the aircraft for the VOR alpha approach into Casa De Aero Airport, instructing the pilot to contact them to cancel the flight plan. At 1848, the aircraft dropped below radar coverage and all communication ceased. While the controller initially suspected a landing had occurred, an ELT signal was detected by a satellite mission control center at 2200.
A CAP ground team narrowed the signal location to a field behind a rural residence at 0230 CST. Due to weather conditions, the team could not access the field until daybreak, and the aircraft was located at 0813 CST.
The investigation
An examination of the wreckage identified rime ice, approximately 1/4 inch thick, adhering to several components. Specifically, ice was found on the leading edges of the left and right horizontal stabilators, the leading edge of the vertical stabilizer, and along a 30-inch section of the right wing's leading edge at mid-span. No other mechanical anomalies were discovered.