NTSB Factual Report

On September 21, 1996, about 1515 central daylight time, an Air Tractor 402, N1517G, collided with trees during an aerial application swath run near Mayersville, Mississippi. The airplane was operated by Lake Washington Flying Service under Title 14 CFR Part 137, and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the flight. The commercial pilot was fatally injured, and the airplane was substantially damaged. Origination of the flight was Glen Allan, Mississippi about 1430 on the same day.

According to the inspector who visited the accident site, the airplane collided with trees at the end of a swath run. The inspector, and the operator who has been an agricultural pilot for about 17 years, stated that they believed the airplane was conducting the spray swath downwind, with about an eight knot tailwind. They indicated in their respective reports that the airplane was scattered through a densely wooded area for about 800 feet. There was general disintegration of the airplane along the debris trail. According to the inspector, the propeller was heavily damaged indicative of high powered rotation during the impact sequence.

The aircraft manufacturer stated that, in the turbine powered airplane, spray runs are typically conducted about 150-170 knots.

NTSB Probable Cause

the pilot's misjudgment of his ground speed and distance to trees during the swath run, and his delayed pull-up at the end of the swath run, which resulted in his failure to remain clear of the trees. The tail wind and location of the trees were related factors.