On September 1, 2007, at 0847 eastern daylight time, a Grumman G-164A, N6578, was substantially damaged during a forced landing in Goshen, New York. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local aerial application flight, which was conducted under 14 Code of Federal Regulations Part 137. According to the pilot, he was ferrying the airplane from one field to a second field, to continue applying fertilizer to crops, when at an altitude of 50 feet, the airplane's engine "coughed or backfired." He performed a forced landing to a farm road, during which the landing gear impacted an irrigation ditch, and the airplane flipped onto its back, substantially damaging the airplane's wings and tail. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed approximately 40 gallons of fuel were drained from the airplane. The nine-cylinder radial engine was rotated by the propeller crankshaft, and valve train continuity and cylinder compression were confirmed. The left magneto was rotated and produced spark at all terminal leads. Examination of the carburetor intake revealed carbon deposits. No additional mechanical anomalies were observed with the airplane or engine. The weather reported at Orange County Airport (MGJ), Montgomery, New York, approximately 7 miles to the north, at 0854, included calm winds, 10 miles visibility, temperature 19 degrees Celsius, dew point 13 degrees Celsius, and barometric pressure setting of 30.16 inches of mercury.