On August 6, 2002, at 2037 eastern daylight time, a Schweizer G-164B, N8444K, piloted by a commercial pilot, sustained substantial damage when it nosed over during a forced landing following a loss of engine power while maneuvering 8 miles north of Sturgis, Michigan. The 14 CFR Part 137 aerial application flight was operating in visual meteorological conditions without a flight plan. The pilot, who was the sole occupant, was not injured. The local flight originated from the Wolfe Field Airport, Shipshewana, Indiana, at 1910. The airplane was being used to spray a cornfield near Sturgis, Michigan. Subsequent to the engine failure, a forced landing was executed in a soybean field adjacent to the field that was being sprayed. During the forced landing, the airplane nosed over. A postaccident examination of the airplane revealed that the turbine section of the engine had failed.