Circumstances:
The pilot reported that the pre-start checks were completed, and the gear selector was noted in the down position with three green lights. The gear unsafe light was tested and found operational. Both engines were started, and when the brakes were released, the aircraft began to roll forward under idle power, as it was parked on a slight downhill slope. The gear warning horn sounded and at the same instant the nose gear collapsed. Both engines stopped when the propellers struck the ground. The drag brace had failed due to overload, allowing the nose gear to collapse. The aircraft had recently been conducting operations from soft wet strips in the Charleville area. The nose gear assembly was twisted out of normal alignment, leading to the drag brace failure. It is considered that this damage may have occurred during the operations from the soft surfaces.
