On September 10, 2003, at 1630 central daylight time, a Burkhart Grob G102 Club Astir IIIB (glider), N424BG, piloted by a commercial pilot, sustained substantial damage when it impacted terrain during an off-airport landing near Highland-Winet Airport (H07), Highland, Illinois. Visual meteorological conditions prevailed at the time of the accident. The flight was operating under the provisions of 14 CFR Part 91 without a flight plan. The commercial pilot reported no injuries. The flight departed H07 at 1600. According to the pilot's written statement, he released the glider from the tow-plane at 3,000 feet. The pilot stated that he "attempted to work several thermals that were weak and soon dissipated." The pilot reported he was unable to gain or maintain attitude and decided to return to H07. The pilot stated he encountered a "strong and prolonged downdraft that caused rapid loss of altitude." The pilot reported he was unable to reach H07 and elected to perform an off-airport landing. During landing, the wingtip of the glider contacted vegetation, which resulted in the glider ground looping and impacting terrain.