On August 31, 1997, approximately 1530 Eastern Daylight Time, a Taylorcraft DCO-65, N4376B, was substantially damaged when it impacted the ground during a forced landing near Fredericksburg, Virginia. The certificated commercial pilot received minor injuries. Visual meteorological conditions prevailed for the cross country flight that departed the Chesapeake Airport, Chesapeake, Virginia, destined for Culpeper County Airport, Culpeper, Virginia. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated that he was in cruise flight at 2,600 feet mean sea level. He had completed 45 minutes of the planned 75 minute flight. The engine speed dropped from 2,600 to 1,300 RPM. The pilot then performed a forced landing to an open field. During the descent he attempted to restart the engine. The pilot applied carburetor heat, checked the magnetos, assured the mixture was full rich and the fuel valve was "ON". When he applied carburetor heat, the engine regained partial power followed by a total loss of engine power. The pilot stated that during the forced landing, he was aligned with a field. As he flew closer to the field, he saw that it was unsuitable for landing, so he initiated a right turn in an attempt to land on another field. While maneuvering the airplane to the second field, the pilot inadvertently stalled the airplane and impacted the ground. He further stated that he did not know what caused the engine to fail. He speculated that there may have been a fuel line clog or carburetor mixture problem. Examination of the wreckage by the FAA Inspector revealed that the airplane came to rest about 70 degrees nose down in an open field. Fuel was present in the right main fuel tank. No fuel was present in the left main fuel tank; however, that fuel tank had ruptured. The fuel was free of contamination. There were no reports of any problems, by other pilots who had received fuel from the same fuel farm as the accident airplane. There was no evidence of mechanical malfunctions. At 1550, the weather reported at the Ronald Reagan National Airport (DCA) was: winds from 180 at 10 knots, temperature 83 degrees Fahrenheit, dew point 70 degrees, visibility 10 statute miles, 4,300 feet scattered, 25,000 feet broken. The weather at DCA was compared to the FAA CT-82/44 Publication: Light Aircraft Piston Engine Carburetor Ice Detector/Warning Device Sensitivity/Effectiveness. According to the publication, the airplane was not susceptible to carburetor ice at cruise power in those conditions.