On March 5, 2006, about 1730 eastern standard time, a LET, model L13 AC Blanik glider, N4413, registered to and operated by Tampa Bay Soaring, as a Title 14 CFR Part 91 personal flight, made a hard landing at Zephyrhills Municipal Airport. Visual meteorological conditions prevailed, and no flight plan was filed. the commercial-rated glider pilot was not injured, and the passenger received minor injuries. The flight originated in Zephyrhills, Florida, the same day, about 1700. The pilot stated that he entered the traffic pattern at 1,000 ft AGL, and at a 45-degree angle. Shortly after announcing the turn to base he said the glider encountered a "strong sink", and he was unable to clear the tree tops at the end of the runway. The left wing hit a tree top, and the glider fell, short of the runway on level ground, incurring damage. According to the pilot, there were no preaccident anomalies associated with the glider.