On October 7, 2003, at 1730 central standard time, a Waco CTO, N9577H, owned and piloted by a private pilot was destroyed after a forced landing in a soybean field when a fire ensued, near Greenfield, Indiana. Visual meteorological conditions prevailed at the time of the accident. The flight was operating under the provisions of 14 CFR Part 91 without a flight plan. The pilot reported no injuries. The flight departed Pope Field Airport (GFD), Greenfield, Indiana, at 1720. According to the pilot's written statement, prior to takeoff a preflight inspection and engine run-up was performed with no anomalies. The takeoff and climb out were uneventful. The pilot reported the engine started to "sputter/cough" and lose power after approximately 4 minutes and 5 miles from the airport. The airplane was at approximately 1,700 feet mean sea level and an airspeed of 80 miles per hour when the power loss occurred. The pilot stated that he initiated a descent to find a suitable landing area. The pilot reported he tried to restart the engine by cycling the magnetos, throttle, and mixture. The pilot also verified the fuel valve was in the "on" position. The pilot stated that he was unsuccessful in restarting the engine. The pilot reported that he aligned the airplane with the rows of a soybean field. The pilot stated the airplane "came over the trees fast, [I] shut off fuel and master switch." The pilot reported the airplane hit the ground "hard and bounced". The pilot stated that after touchdown, he smelled "smoke" that could have been an electrical smell. The pilot reported the airplane stopped in 900 feet. The pilot stated the accident site was "dusty" and he could not tell if the smoke was visible or not. The pilot reported that after he exited the airplane he saw a fire burning under the fuel tank around the battery box. The pilot stated that he left the area and after he was approximately 20 feet away, he turned and saw the fire had burned through the fabric under the fuel tank on the left side. The pilot reported the airplane became engulfed in flames. A Federal Aviation Administration (FAA) inspector examined the airplane subsequent to the accident. The FAA inspector reported that the fire consumed the majority of the airplane. Both upper and lower wings were consumed to approximately the outer 2/3's of the span. The engine and propeller sustained minor damage. The fuel tank was ruptured in three places. The fuel line from the tank to the shutoff valve had three ruptures and was melted off the shutoff valve. The fire destroyed the fuel line from the shutoff valve to the gascolator, as well as the gascolator. The magnetos, spark plugs, and the valve train and accessory gearbox were checked, and no discrepancies were noted. The fire's initiating event was not identified.