A witness on duty at the airport heard an airplane circling very low overhead; it made several circles and then the sound ceased. She said the weather was 'very, very foggy', and heard several 'clicks' similar to the activation of an airplane microphone. The wreckage was found 2/19 approximately 300 ft north of the approach end of RWY 33. The pilot's 'memo' book showed that he had practiced LORAN approaches to the airport. The pilot's CFI endorsement for solo flight had expired 3/19/90. The airplane had been earlier impounded and chained by a Federal Marshall as a result of an incident wherein the pilot had landed at the airport twice during the hours of darkness without a clearance from the control tower or any other radio communications. The pilot's toxicological tests detected cocaine in the urine, and benzoylecgonine in the urine (43.300 ug/ml), blood (0.390 ug/ml), liver (0.394 ug/ml) and kidney (0.207 ug/ml).