On November 7, 2001, at 0800 central standard time, an Air Tractor AT-301 agricultural airplane, N2316X, was substantially damaged during a forced landing following a total loss of engine power while maneuvering near Anton, Texas. The airplane was registered to Pest Elimination Systems Inc., of Littlefield, Texas, and operated by Brown Flying Service of Littlefield, Texas. The commercial pilot, sole occupant of the airplane, was not injured. 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 originated from the Littlefield Municipal Airport, Littlefield, Texas, at 0710. According to the pilot, he was applying malathion to a field. After spraying for 20 minutes, the engine "slowly started to lose power." The pilot abandoned the spray operation and initiated a return flight to the base airport in Littlefield. However, during the return flight, the engine lost total power, and he executed a forced landing to a field. During the landing roll, the airplane contacted a dirt terrace, the left main landing gear wheel separated, and the airplane nosed over, coming to rest inverted. The FAA inspector, who examined the airplane at the accident site, reported that the right wing, including the wing's spar, was structurally damaged, and the canopy was flattened. The Pratt & Whitney R-1340 engine was transported to Younkin Aviation, Inc., Fayetteville, Arkansas, for examination and overhaul. A mechanic reported that the #5 cylinder displayed a crack that initiated at one spark plug, continued over the cylinder head, and ended at the second spark plug. The crack went through the entire thickness of the cylinder's casting. He reported that the #6 cylinder displayed a crack in the casting that measured between 1 and 2 inches in length. The mechanic did not note any other anomalies. A review of the powerplant logbook revealed that on February 20, 2001, the engine underwent its last 100-hour inspection. The logbook entry stated that the compression on each of the cylinders was "above 70/80." According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), at the time of the accident the engine had accumulated 257.0 hours since the 100-hour inspection, and 709.0 hours since its last overhaul.