On June 3, 1999, about 1745 eastern daylight time, a Robinson R-22B, N221DD, was substantially damaged while landing at the Jaffrey Airport (AFN), Jaffrey, New Hampshire. The certificated commercial pilot, and the certificated flight instructor (CFI) were not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the local instructional flight, which was conducted under 14 CFR Part 91. The commercial pilot owned the helicopter and had previously received training for a flight instructor rating from another CFI. According to the commercial pilot, the CFI was acting as a safety pilot for the flight. According to the CFI, the pilot departed runway 34 at AFN, climbed to 1,700 feet, and entered the traffic pattern for a practice autorotation. When the helicopter was abeam the end of the runway, the pilot entered the autorotation. While on final approach, the wind was blowing the helicopter away from the runway. The helicopter's main rotor RPM began to decrease and the pilot lowered the collective to bring the RPM back into "the green," which increased the helicopter's descent. When the pilot realized he was "short" of the runway, he opened the throttle, pulled up on the collective, and attempted a go-around. However, the skids contacted the ground and the helicopter landed "hard." Examination of the accident site by a Federal Aviation Administration (FAA) Inspector revealed the helicopter contacted the ground, 178 feet short of the paved part of the runway. Both landing gear skids made deep impressions in the soil just prior to a large rock. A second impact point was located at the beginning of the paved part of the runway, and skid marks were observed from the second impact point to the helicopter's final resting place, a distance of 31 feet. During the impact, the main rotor severed the tail boom. The pilot stated he experienced no mechanical problems with the helicopter. Winds reported at the airport at about the time of the accident, were from 290 degrees at 8 knots, with 15 knot gusts, variable between 270 and 360 degrees.