During spraying operations the engine suffered a partial power loss. The pilot initiated dumping of the hopper load but was unable to prevent the aircraft from striking the ground heavily. The landing gear collapsed and the aircraft slid for about 50 metres before coming to rest. The reported power loss had occurred during a procedure turn, the latter portion of which was downwind. No fault was subsequently found with the engine, however it was considered likely that the aircraft was affected by downdraughts in the lee of a hill. When dumping was initiated, the pilot's left sleeve had probably caught on the throttle lever and pulled it towards the closed position.
