On December 2, 1996, at 1545 central standard time, a Let L23 glider, N290SB, was substantially damaged while landing near Bryan, Texas. The glider, owned and operated by West Wings Aviation of Bryan, Texas, was being operated under Title 14 CFR Part 91. The commercial pilot, sole occupant of the aircraft, was not injured. Visual meteorological conditions prevailed for the personal local flight for which a flight plan was not filed. The glider departed in tow from Coulter Field at 1515. According to the pilot, the glider was released from the tow plane at 3,000 feet. After soaring for approximately 25 minutes in the vicinity of the airport, he maneuvered the glider to land on runway 17. The pilot added that on final approach, at approximately 250 feet AGL, "the sail plane encountered a sink" and he realized that he would not be able to reach the airport and clear the power lines at the approach end of the runway. The pilot stated that he elected to execute an "off airport landing" in a field north of his position. The pilot turned right and executed a downwind landing in the field he selected. The pilot added that the 15 knot tailwind substantially increased the glider's ground speed and ground roll. During the landing roll, the root of the glider's right wing impacted a fence post resulting in a loss of control. Post accident examination of the glider by the operator revealed structural damage to the airframe as well as the right wing. The pilot stated that the winds at the time of the accident were from 180 degrees at 15 knots. The commercial pilot was rated in single and multi-engine airplanes. He was properly endorsed by a flight instructor for solo flights in the glider and had accumulated a total of 8.9 hours in gliders, of which 4 hours were solo.