1970 Ka 6 CR Glider Accident Near Wellhausen, Switzerland (HB-996)

Incident Overview and Outcome The accident occurred on Sunday, 7 June 1970, near Wellhausen, Canton of Thurgau, during a competition glider flight. The glider collided with a tree and fell from a low altitude after an off-airfield landing attempt. The pilot sustained serious injuries, and the glider was severely damaged. No significant third-party damage to the ground was recorded. ## Aircraft and Operational Details The aircraft was a Ka 6 CR glider, registration HB-996, owned by Segelfluggruppe Winterthur (Zürich section of AéCS). It was a single-seat, free-flying, shoulder-wing design in wooden construction with a fixed wheel, built in 1966 by Flugzeugbau Paul Siebert in Münster, West Germany, with serial number 6534/Si. The glider was airworthy, had 100 hours 26 minutes and 263 landings, and its weight and center of gravity were within prescribed limits at 285 kg and 256 mm behind the datum. ## Pilot Background The pilot was born in 1943 and held a valid glider pilot license issued by the Federal Air Office, along with a provisional glider instructor permit and a silver international performance badge. By the date of the accident, he had 118 hours 6 minutes of glider experience with 484 landings, and 25 hours 22 minutes in the Ka 6. His last medical examination on 23 April 1969 found him fit, with no further incidents recorded except a student landing mishap. ## Weather and Terrain Meteorological data indicated 6/8 cloud cover, variable winds of 3-5 knots, visibility 15 km, temperature 23°C, and QNH 1011 mb, with irregular thermals near the ground. The local area near Wellhausen included a mowed field approximately 800 x 100 meters suitable for landing, a road embankment with high lighting masts spaced 34 meters apart, and small trees about 5 meters high in the intervals. ## Flight Progression and Cause The pilot took off from Schaffhausen airfield at 1051 for a competition triangular flight of about 90 km. After reaching Thayngen at around 900 meters, he proceeded toward Amlikon, reaching about 1200 meters before losing altitude due to lack of lift. Near Wellhausen, at about 300 meters, he decided on an off-airfield landing. He initially selected a nearby mowed field, overflew it at 200 meters in a left curve, and later changed course to another suitable area. The late landing decision and misjudgment of height led to a collision with a tree, causing the crash.