THE ACFT COLLIDED WITH WOODED, RISING TERRAIN AT AN ELEVATION OF ABOUT 2800 FT MSL ON THE WEST SLOPE OF HINCH MOUNTAIN. A PASSENGER, WHO SURVIVED THE CRASH, BUT DIED LATER DUE TO BURNS, REPORTED THAT LIGHT CONDITIONS WERE DARK & SHE COULD NOT SEE ANYTHING OUTSIDE THE ACFT BEFORE IMPACT. SHE HEARD THE PLT REPORT ON THE RADIO THAT THERE WAS ICE ON THE ACFT. HE HAD OBTAINED 5 FSS WX BRIEFINGS PRIOR TO TAKEOFF. A COLD FRONTAL SYSTEM WAS ON HIS PROPOSED FLT PATH. THERE WERE NUMEROUS PLT REPORTS OF ICING CONDITIONS IN THE ST LOUIS AREA & IN TENNESSEE. ANOTHER PLT REPORTED ICE IN THE CLOUDS NEAR THE CRASH SITE. THE PLT OF N4716R HAD TOLD FRIENDS THAT HE HAD MUCH MORE FLT EXPERIENCE THAN HE ACTUALLY HAD. ALSO, HE TOLD THE FSS BRIEFERS HE WAS INSTRUMENT RATED. ABOUT 11 MI AWAY AT CROSSVILLE, TN, THE 1450 & 1526 CST WX WAS IN PART: 200 FT OBSCURED, VISIBILITY 1/2 MI WITH FOG, TEMP 32 DEG & DEW POINT 31 DEG. THE ELEV AT CROSSVILLE WAS 1881 FT. AN INVESTIGATION REVEALED EVIDENCE THE ACFT WAS IN LEVEL, POWERED FLT WHEN IT CRASHED.