On June 19, 2000, about 1630 Eastern Daylight Time, a Schempp-Hirth, Ventus 2CM motorglider, N800PF, was substantially damaged while maneuvering to land at the Warren-Sugarbush Airport, Warren, Vermont. The certificated commercial pilot was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal local flight conducted under 14 CFR Part 91. According to a Federal Aviation Administration inspector, the pilot was participating in a glider race at the airport. The race was to be conducted without motorized power and the motorglider was towed to altitude. According to the pilot, after crossing the finish line at the end of the race, he received a radio call from the airport that the winds had changed direction and landings were being conducted on Runway 22. The pilot executed a 180-degree turn and entered the traffic pattern for the runway. While turning base to final, the pilot was unable to stop the turn with full opposite aileron due to turbulence. As the motorglider descended, the pilot was able to level the wings, but was 90 degrees to the runway and "into the trees." The pilot raised the nose of the glider to decrease airspeed, and the motorglider stalled, impacting trees short of the runway. The winds reported by an airport located about 13 miles east of the accident, at 1651, were from 350 degrees at 7 knots.