On August 26, 2010, approximately 1035 central daylight time, an Air Tractor AT-401, N4530L, was substantially damaged during a forced landing to a field near Castroville, Texas. Visual meteorological conditions prevailed at the time of the accident. The aerial applications flight was being conducted under the provisions of 14 Code of Federal Regulations Part 137 without a flight plan. The commercial pilot was not injured. The local flight departed D'Hanis, Texas, approximately 1000. According to the written statement received from the pilot, he was pitching the airplane up to reverse direction when the "engine spooled down." The pilot leveled the airplane and attempted to restart the engine without success. During the forced landing, the airplane impacted several trees and bushes. Several ribs in the right wing were crushed aft and bent and the right wing spar was bent aft. According to the Federal Aviation Administration inspector who traveled to the scene, and was present during the engine examination, the torque sensor bearing failed resulting in the shutdown of the fuel system.