What happened
During an aerial spraying mission, a pilot was operating an aircraft beneath 110,000-volt electrical transmission lines. Having successfully completed several previous sorties over the same property without incident, the pilot had navigated under the conductors at least six times during the initial run of the day. After reloading the aircraft for subsequent passes, the pilot continued the spraying operation under the power lines.
During one of these later runs, the aircraft encountered a single tree that necessitated a change in flight path. To clear the obstacle and maintain the necessary trajectory, the pilot lowered the nose of the aircraft to fly beneath the high-voltage conductors before pulling up to clear a nearby stand of trees. During this maneuver, the aircraft struck multiple power lines. The impact caused the aircraft to skid across the crest of a hillside, eventually coming to a stop 370 meters past the transmission line infrastructure. The pilot suffered serious back injuries as a result of the impact.
The investigation
The investigation focused on the flight path and the maneuvers required to navigate the terrain and obstacles. It was established that the pilot was familiar with the area and had successfully navigated the power lines on multiple occasions prior to the accident. The investigation examined the sequence of the flight, specifically the necessity of lowering the aircraft's altitude to clear a tree and the subsequent attempt to climb back above the conductors.