The pilot had been issued an instrument rating on 8/6/82 and had logged 5.6 hrs since that time. The pilot's instructor believed this would have been his first low approach in actual instrument conditions since he completed his check flight. A witness stated that before takeoff, the pilot appeared nervous about his departure and it appeared that he needed to get somewhere despite the weather. After receiving a weather briefing, he departed on an IFR flight plan with known rain, fog and low ceilings at the destination. During arrival the pilot was cleared for an ILS approach to runway 12. At about the position that he would be intercepting a VOR arc to transition to the ILS, radio and radar contact were lost. Later the aircraft was found where it would have intercepted the arc in a left turn. At that point, it had impacted the ground in a nose low, left wing low attitude. An examination of the engine and flight controls revealed no evidence of mechanical malfunction or failure prior to ground impact.