The pilot reported that he had been flying over his farm for about 30 minutes inspecting his crops and livestock. When crossing a road, whilst proceeding to another section of the farm at a altitude of about 30 feet, he remembered the location of a powerline, which was then only 50 metres ahead. He banked the aircraft left to avoid the line, but the left wing hit the top of a tree. Control was lost and the aircraft impacted the ground, coming to rest inverted. The pilot stated that during the flight he had been preoccupied thinking about the several tasks he hoped to complete that day. Consequently he was not giving his full attention to the operation of the aircraft. During the impact sequence the insert plug in the fuel tank became dislodged. This allowed fuel to spill from the tank and drench the pilot.
