The aircraft was outbound from Adelaide on the first sector of a daily bank run and was being operated at night under the Instrument Flight Rules. The pilot reported that the township lights of Minlaton were visible during the descent, and the runway lights were clearly visible from a distance of about 12 NM. The pilot joined the circuit on a downwind leg for runway 15 and said that the runway lights were visible on both downwind and base legs. Shortly after turning final, at a height of approximately 400 ft, the pilot initiated a missed approach after losing sight of the runway. The runway lights were visible as the aircraft passed overhead the aerodrome, as were the lights of a motor vehicle passing the southern end of the runway. The pilot elected to attempt another approach for runway 15, with the option of landing on runway 33, if the second approach was unsuccessful.
A second circuit was flown at about 800 ft, with the runway lights remaining in sight on the downwind and base legs. Shortly after turning final the aircraft entered patchy low cloud that was obscuring the runway lights for brief periods. The pilot reported that he was in the process of commencing a second missed approach when he regained visual contact. He reduced power but again lost contact. While searching for the runway lights he initiated a missed approach but felt the main wheels touch down. He immediately closed the throttles and allowed the aircraft to roll to a stop.
The aircraft had touched down in a paddock approximately 800 m before the runway threshold and had rolled normally on its landing gear for about 600 m. However, the aircraft was substantially damaged when it entered a lightly timbered area at moderate speed. The pilot sustained minor injuries.
The Area 50 forecast prepared by the Bureau of Meteorology, valid from 0130 to 1430 Central Standard Time, indicated that the aircraft would be operating to the west of a trough moving through the area. Isolated showers and drizzle, together with broken low cloud on the coast and western slopes, were forecast until 1130. Isolated fog patches were forecast until 1030.
The terminal area forecast (TAF) issued for Minlaton at 0434 for the period 0530 to 1730, predicted a light south-westerly wind and rain showers. Broken cloud cover was forecast at a height of 2,500 ft, with a few lower patches at 1,200 ft, together with a visibility greater than 10 km. The forecasting officer preparing the TAF considered the possibility of low stratus, fog or drizzle affecting aircraft operations into Minlaton. However, each was discounted on analysis of the synoptic situation and on other available information. The Minlaton TAF was reviewed at 0600 but it was considered that no amendment was required. The Bureau prepares regular aerodrome forecasts for Minlaton, without the benefit of local weather observations.
The pilot subsequently lost visual contact with the runway lights at low altitude when the aircraft entered a localised area of cloud or fog, at a height lower than forecast. The aircraft had then inadvertently contacted the ground while the pilot was initiating a missed approach.