The aircraft had been chartered to convey seven passengers, their luggage and a quantity of freight from Brisbane to Trinidad Station. When the pilot arrived at Archerfield Aerodrome on the morning of the flight, he found that the aircraft had a fuel load that was too great to allow the expected passenger and freight loading to be carried. He therefore arranged for the aircraft to be defuelled. When the passengers and freight arrived, the pilot learned that the freight load was less than had been originally advised and he stopped further defuelling. The aircraft departed Archerfield at 0900 hours and arrived at Charleville at 1045 hours, where additional fuel was added before completing the flight to Trinidad Station. After arriving in the vicinity of Trinidad Station the pilot experienced some difficulty in locating the strip. He consulted several passengers about its position in relation to a seismic survey camp that had been seen on descent. The strip was located after about five minutes and the pilot positioned the aircraft to join the circuit on the downwind leg for landing into the northwest. On final approach, a passenger who was seated in the third row of seats observed that the landing gear position indicating lights on the instrument panel indicated that the gear was up. He shouted and drew the attention of the passenger seated in front of him to the problem, who in turn tapped the pilot on the shoulder and pointed to the landing gear position indicator lights. Almost immediately both propellers struck the ground. The pilot applied power and rotated the aircraft. The left engine stopped as a result of the propeller striking the ground and the pilot was seen adjusting the engine controls, apparently either attempting to feather the left propeller or restart the left engine. The aircraft climbed to between 150 feet and 300 feet above the strip, where it levelled out before gradually yawing and banking to the left. The yaw and bank increased and the aircraft descended, struck the ground on the left engine and nose section 310 metres to the left of the strip and slid backwards for about 20 metres before coming to rest. Inspection of the wreckage revealed that the landing gear was up and had not been selected down. The aircraft was fitted with a gear warning system that activated an aural alarm when the engine throttles were retarded below 14" manifold pressure and the gear was not in the down position. Although this system was serviceable at the time of the accident, it was company policy that the pilots not reduce the throttle settings below 15" manifold pressure until the aircraft had touched down. It was estimated that during the go-around attempt the available power from the right engine would have been reduced by at least 25 per cent due to propeller blade damage.