What happened
On July 30, 2016, a Schempp-Hirth Duo Discus T glider was participating in a summer camp at the Jena-Schöngleina airfield. The aircraft, which was registered in the Netherlands, was being prepared for a winch launch by a pilot and a crew member.
During the initial phase of the takeoff roll and lift-off, witnesses observed a normal flight profile. The glider accelerated and climbed at a shallow angle to an estimated altitude of 10 to 15 meters. Suddenly, the nose of the aircraft pitched downward, causing the towline streamer to inflate and the towline to drop. The glider lost altitude rapidly and struck the grass runway hard with its nose and left wing. Following the initial impact, the aircraft slid in a slight left curve for approximately 68 meters before coming to a stop.
One person was seriously injured and one person was lightly injured in the accident. The glider sustained heavy damage.
The investigation
The BFU examined the aircraft and the winch equipment used during the incident. The investigation focused on the mechanical integrity of the glider, the towline, and the winch system. The investigation also reviewed the pilot's credentials, noting she held a valid glider pilot license with sufficient experience, including over 130 hours on this specific model.
Upon inspection of the aircraft, investigators found that the towline ring pair had become disconnected. The landing gear had collapsed, and the fuselage had broken away at the level of the registration area. However, an examination of all control linkages and flight controls revealed no evidence of technical defects in the aircraft. The H4 Hercules winch and the synthetic towline, which featured the required weak links and a double ring pair, were also inspected and found to be in proper working order.