What happened
On May 25, 2017, a PZL Bielsko SZD 55-1 glider, registration D-5518, was preparing for a towed takeoff at the La Tour du Pin Cessieu airfield. The aircraft was aligned on the takeoff axis, which is oriented west-northwest/east-southeast. Following standard procedures for this aircraft type, the pilot maintained the airbrakes partially extended and applied back pressure on the stick to keep the tailwheel on the ground and stabilize the glider against potential crosswinds.
As the tow plane began the takeoff roll, the pilot initially maintained a straight track and level wings. However, a significant increase in rightward yaw developed. Despite the pilot applying left rudder and stick inputs, the aircraft failed to correct the deviation. The tow cable eventually formed an angle of more than 20 degrees relative to the glider's flight path. Realizing the deviation was unrecoverable, the pilot released the airbrakes and pulled the release handle.
Upon retracting the airbrakes, the glider lifted approximately one meter off the ground. The combination of control surface deflection and the lateral pull of the tow cable caused the glider to bank and turn sharply to the left. During this maneuver, the tow cable disconnected. The glider subsequently fell 90 degrees relative to its original path, striking the ground. The impact of the main wheel against the surface caused the tail boom to break, resulting in heavy damage to the aircraft.
The investigation
The investigation examined the pilot's actions, the aircraft's handling characteristics, and the environmental conditions. The pilot, who had 82 total glider flight hours (including 31 on this type), noted that the deviation might have been caused by a wind gust or the propeller wash from the tow plane. The investigation also reviewed the operational procedures for takeoff rolls in this specific glider model, noting that the pilot's initial attempt to correct the yaw using the stick may have complicated the situation.