On May 25, 2003, approximately 1315 central daylight time, an Ayres S2R-G6 single-engine agricultural airplane, N6136Z, sustained substantial during a forced landing following a loss of engine power while maneuvering near Palestine, Arkansas. The commercial pilot, who was the sole occupant of the airplane, was not injured. The airplane was registered to and operated by Chism Flying Service, Inc., near Brinkley, Arkansas. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 137 aerial application flight. The local flight departed a private airstrip near Brinkley at an unknown time and was returning to the airstrip at the time of accident. According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), after completing an aerial application of a chemical fertilizer, the pilot was returning to the private airstrip to reload the hopper and refuel the airplane. During the return flight, "the airplane felt like it tried to nosedive." The pilot checked the power settings, extended the flaps, and initiated a forced landing to a field. During the forced landing, the airplane struck a levee and came to rest upright. Examination of the aircraft by an FAA inspector, who responded to the accident site, reported the left wing and both flaps were bent. On June 3, 2003, at the facilities of Kelner Turbine, a FAA certified repair station, near Neosho, Missouri, the Garrett TPE-331-6 engine was disassembled and examined for subsequent repair. The examination revealed that the torsion shaft was fractured at the shear point on the shaft. According to the examination report, " the torsion shaft sheared thus uncoupling the power section from the gearbox. With nothing driving the gearbox the engine would begin to spool down because the fuel pump will not have enough pressure to keep it running. This is when [the mechanic] feel the pilot noticed no response from the throttle. The emergency stop and feather lever was not pulled therefore the prop[eller] did not go to the feather position. The result is a flat-pitched prop[eller], which causes enormous drag that made the nose of the aircraft pitch down just as the pilot reported."