Incident Overview
On August 10, 2008, at 0635 central daylight time, an Air Tractor AT-802A (registration N9078G) collided with a ditch during an off-airport forced landing in Turton, South Dakota. The pilot, the sole occupant, was not injured. The airplane sustained substantial damage. The flight was conducted under 14 Code of Federal Regulations Part 137 as an aerial application operation by Wilbur-Ellis Air LLC. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Huron, South Dakota, at 0615.
Sequence of Events
According to the pilot, while in cruise flight at approximately 500 feet above ground level, the radios began "popping and breaking squelch." He realized the generator system had failed. Approximately 30 seconds later, the engine began to lose power. The pilot advanced the throttle and turned back toward the departure airport. The engine then began to vibrate and rapidly lose power. The pilot dumped the chemical load and identified a road on which to land. During the landing roll, the left wing caught in the tall grass alongside the road, spinning the airplane around and into a ditch.
Post-Accident Findings
The pilot reported that the starter generator failed, which was followed shortly thereafter by the loss of engine power. He also stated that the starter generator was on fire after the accident.