The pilot and three passengers had flown to Nyngan earlier in the evening and had spent about 4 hours on the ground with the owner of a nearby property. Some of the time on the ground was spent at 2 hotels in the township, where alcoholic beverages were consumed by all members of the group. After take off for the return flight, the aircraft flew to the property, where it was observed to pass low over the homestead. The lights of the aircraft disappeared soon after and the sound of a ground impact was heard. The wreckage was discovered about 4 hours later. The aircraft had initially collided with a tree and then rolled inverted and dived into the ground at high speed. The evidence indicated that the pilot was attempting a deliberate low pass over the homestead. During this manoeuvre, he apparently misjudged the height of the aircraft above the ground. A detailed examination of the aircraft did not reveal any mechanical defect which could have contributed to this occurrence. The engine was delivering high power at the time of impact with the ground. A toxicological examination of blood samples taken from the pilot revealed a concentration of blood alcohol, which medical opinion concluded would have adversely affected his rational judgement and manipulative skills.