On August 19, 1995, about 1745 eastern daylight time, a Let Blanik L-13, glider, N69AS, operated by Aero Soaring Club Inc., was substantially damaged when it ground looped during the landing at the Dart Airport, Mayville, New York. The student pilot was not injured. Visual meteorological conditions prevailed for the instructional flight that departed Mayville at 1705. No flight plan had been filed for the local flight conducted under 14 CFR Part 91. In the NTSB form 6120.1/2, the pilot stated: ...I noticed a small plane moving down runway 31. I was intending to land on 13....I altered my base leg, hoping to cut back and land halfway down the runway, thus landing behind the small plane. I landed in the high grass west of the runway, about 10 feet from the edge of the runway....Not wanting to roll across the runway into the powerlines, ditch, or road, I applied full right rudder and deployed my spoilers. I hadn't noticed that my right wing had not yet cleared the high grass west of runway....The glider did a 180 degree turn....My wingtip dipped, caught in ground and damaged glider. The sole cause of the damage to the glider was the ground loop instigated by my applying rudder while wing was still in grass.... Additionally, at the time of the accident, the winds were reported as calm, and the pilot had approximately 18 hours of total flight time, of which 1 hour was solo time.