The pilot was engaged in sheep mustering. The aircraft was being flown at 200 feet agl, and about three minutes after the fuel tank selection was changed , the engine lost power. The pilot selected the other fuel tank but the engine did not respond. The aircraft touched down heavily on unsuitable terrain and the main gear collapsed. No defect was found with the engine and 55 litres of fuel was drained from the fuel system following the accident. It is considered probable that the loss of power resulted from fuel starvation caused by the pilot inadvertently turning the fuel selector beyond the correct position. An inspection of the fuel selector valve found that it had been incorrectly assembled. This resulted in there being no effective detent to indicate that the selector had been correctly positioned. Also it was found that if the selector was positioned slightly beyond the required position, fuel flow was considerably restricted.
