Primary finding
Probable cause
The flight's encounter with an area of no thermal lift. Contributing factors to the accident were the pilot's inadvertent selection of unsuitable terrain with a hidden obstruction.
Investigator assessment
Analysis narrative
After being towed to an altitude of 1,800 feet, the pilot of the LET L-33 Solo glider released the towline and began "thermaling" to the northwest of the airport. After flying for approximately 11 nautical miles uneventfully, the pilot turned back to the airport. Then while thermaling on the return leg, the glider lost altitude due to the "lift conditions," and the pilot performed an off-field landing. After touching down in a hay field, the glider struck a grass covered culvert and was substantially damaged.
Source record
Factual narrative
After being towed to an altitude of 1,800 feet, the pilot of the LET L-33 Solo glider released the towline and began "thermaling" to the northwest of the airport. After flying for approximately 11 nautical miles uneventfully, the pilot turned back to the airport. Then while thermaling on the return leg, the glider lost altitude due to the "lift conditions," and the pilot performed an off-field landing. After touching down in a hay field, the glider struck a grass covered culvert and was substantially damaged.