The pilot submitted flight plan details to Moorabbin by telephone at approximately 1245 hours EST indicating that he intended to track direct to Mildura at an altitude below 5000 feet and that the estimated time for the flight was 104 minutes. At 1334 hours the pilot advised Melbourne Flight Service Unit by radio that he had departed from Lovely Banks at 1330 hours and estimated that he would be over Maryborough at 1400 hours. This communication was acknowledged and no further calls were received from the aircraft. Between 1345 hours and 1350 hours, the sound of an aircraft was heard in the Yendon area, some 15 miles south east of Ballarat. The engine noise, which was normal when first heard, rose to a high pitch and intensity and then ceased abruptly. The wreckage of the aircraft was found shortly afterwards at a position approximately 2 miles west of the direct track from Lovely Banks to Maryborough. Examination of the wreckage indicated that the aircraft had struck the ground at high speed in a steep nose down attitude. The aircraft disintegrated on impact and there was no fire. There is evidence from witnesses on the ground in the general vicinity of the accident site that the cloud base was low and there were showers in the area. Another pilot, on a flight from Melton, was approaching the Yendon area a few minutes before the time of the accident and was forced to turn back when he encountered increasing cloud and a lowering cloud base with considerable rain ahead.