The pilot was to conduct seeding operations on a friend's property. On arrival at the strip, he removed the front right seat from the cabin, leaving only the pilot's seat in the aircraft (the rear passenger seats were not in the aircraft). The pilot then fitted shaped metal sheets to the top and bottom of the baggage door. The door was positioned at the rear of the cabin on the left side of the aircraft. The metal sheets enabled the door to be held open (at an angle of about 17`) during flight, to allow seed to be dispensed through the opening. The seed mixture was contained in bags, each weighing about 45 kg. Four bags were loaded into the aircraft cabin. One bag was placed adjacent to the baggage door. The person dispensing the seed then sat on the cabin floor leaning against the cabin rear bulkhead. Two further bags were placed on the floor in the area normally occupied by the rear passenger seats and another bag on the floor in the position of the front right seat. About 10 min after the aircraft departed for the seeding area, the property owner became concerned that he had not seen or heard the aircraft and commenced a search. He located the wreckage some 25 min later. From the evidence available at the site, the aircraft impacted the ground at low speed and with a high rate of descent. Some flap (probably one notch on the selection handle) was selected at impact but whether this was a normal configuration for seeding operations could not be determined. The impact was not survivable, the forces being sufficient to cause the pilot's inboard lap safety belt attachment bracket to fail in overload. Examination of the seed bags indicated that one bag was probably empty of seed at impact. Nothing to indicate a pre-existing defect in the aircraft controls or engine was found. It appears that the pilot had conducted one seeding run and was conducting a right procedure turn to position for the next run when the accident occurred. It was established that the pilot had received no formal training in low flying or aerial agriculture techniques. The exact sequence of events leading to this accident could not be determined.