On October 9, 2004, at 1222 eastern daylight time, a Boeing B75-N1 Stearman, N49738, was substantially damaged during a forced landing after departing from the Silver Ranch Airport (AFN), Jaffrey, New Hampshire. The certificated airline transport pilot and passenger received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed for the local sightseeing flight that was conducted under 14 CFR Part 91. According to the pilot, he taxied to runway 16 and attempted to takeoff, but had trouble keeping the right wing down. He aborted the takeoff and decided from the position of the windsock that it would be the better to takeoff from runway 34. As the airplane neared the departure end of the runway, he observed another airplane approaching to land on runway 16, which subsequently initiated a go-around. The pilot then positioned the airplane onto the runway, and began his takeoff roll. At an altitude of approximately 300 to 350 feet, after passing the departure end of the runway, the airplane started to descend. The pilot recognized this as windshear and prepared for a forced landing. In an effort to avoid trees and a residential area ahead, the pilot turned the airplane to the right, and performed a forced landing to a field. Upon touching down hard in the field, the airplane nosed over and came to rest inverted. The pilot added that he observed the windsock as indicating a northwest wind at 15 knots, and that the engine was developing full power during the flight. The pilot reported he had accumulated about 23,000 hours of total flight experience, of which about 1,000 hours were in make and model. The winds recorded by an ASOS at AFN, at 1152 were from 190 degrees, at 11 knots. The winds reported at 1252 were from 200 degrees, at 10 knots, gusting to 19 knots.