On August 28, 1995, at 1648 hours Pacific daylight time, a Elan/Glaser Dirks DG-300 Elan glider, N300HX, collided with terrain short of the runway while on final approach to Truckee-Tahoe Airport, Truckee, California. The aircraft was destroyed and the private pilot sustained serious injuries. The aircraft was being operated on a personal flight by the owner when the accident occurred. The flight originated in Truckee at 1400 on the day of the accident. Visual meteorological conditions prevailed at the time and no flight plan was filed. A witness reported seeing the glider on downwind for runway 19. He said the glider looked a little low as the pilot began his base to final turn. He stated that he saw the spoilers being retracted and that the pilot appeared to lower the nose of the aircraft in what he believed was an effort to increase airspeed. As the glider neared final, it descended below a bluff at the approach end of the runway. He then saw a cloud of dust rising into the air and ran toward the edge of the bluff. Looking down the slope, he saw the glider near the base. As he approached, he noticed that the aircraft's empennage had separated and there were ground scars on the bluff leading up to the aircraft. As he reached the glider, he found the pilot injured, but conscious, still inside the cockpit. The pilot stated that he had obtained a recorded weather briefing prior to departure in which winds from 010 degrees at 13 mph, gusting to 23 mph, were expected. He said these conditions had existed almost daily for the previous 2 weeks. The pilot reported that he entered the traffic pattern for runway 19 at 7,700 feet msl, 700 feet higher than the established pattern altitude, to avoid the turbulence he expected to encounter. His pattern airspeed on downwind was about 55 knots. Abeam the approach end of runway 19, the pilot partially deployed his spoilers. He made a call on the CTAF frequency announcing a turn to base. While in the turn, the pilot said he did not get the increase in airspeed he had expected. He continued the turn and noted that his altitude was now 6,600 feet msl. He applied control pressure to maintain airspeed and "increase penetration." He maintained that his altitude was more than adequate to execute a safe landing; however, when he neared the runway threshold, the aircraft encountered turbulence and a high sink rate so severe that he lost flying speed, resulting in a crash. The FAA inspector who responded to the accident scene reported that the prevailing winds were causing down stream turbulence at the end of the runway 19. He described the terrain at the runway's approach end as dropping off approximately 175 feet on a 50- to 65-degree downslope. Witnesses reported to him that the aircraft was in a steep descent with the spoiler deployed. As they continued watching, the spoilers were retracted but the aircraft continued to lose altitude rapidly until it had descended below terrain at the end of runway 19. The inspector estimated that the aircraft impacted in nose-high attitude, bounced, and came to rest about 119 feet from the threshold of runway 19, 25 feet from the initial impact point.