On August 28, 1999, at 1300 central daylight time, a Grob 103C glider, N103MS, struck a tree during the final approach to runway 17 at the Boerne Stage Field Airport near San Antonio, Texas. The glider was owned and operated by Alamo Aerodyne Corporation, San Antonio, Texas, under 14 Code of Federal Regulations (CFR) Part 91. The solo student pilot received serious injuries and the glider sustained substantial damage. Visual meteorological conditions prevailed for the local solo instructional flight and a flight plan was not filed. The flight departed the Boerne Stage Field Airport at 1200. Witnesses and local authorities reported that the student pilot, while turning final approach, over shot the runway. The pilot was correcting the flight path toward the runway when the right wing struck a tree approximately 5 1/2 inches in diameter. The glider pivoted around the tree and stuck the ground in a nose down attitude. The glider came to rest approximately 300 feet short of the runway. The FAA inspector and the glider owner examined the glider and found that the inboard 18 to 24 inches of the right wing was damaged and the forward cabin was crushed. Approximately 4 1/2 feet of the outboard right wing was found separated from the glider. The student pilot had 15.2 hours of total flight time in gliders. The student was endorsed for solo flight and had 2.4 hours of solo flight time in the glider. On the Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2, the operator reported that the accident could have been prevented by "maintain[ing] adequate clearance over obstacles." The National Weather Service observation for San Antonio, Texas, (located 13 nautical miles west of the accident site), at 1255 was 96 degrees Fahrenheit with an altimeter setting of 29.90 inches. The NTSB investigator-in-charge calculated the density altitude at 4,215 feet.