What happened
On August 8, 2009, a two-seat Schleicher ASK 21 glider departed from the Fischbek airfield via a winch launch. The flight was initiated at approximately 15:07 local time, with the aircraft accelerating toward runway heading 120°. During the takeoff roll, the left wing made contact with the ground. This contact induced a violent yawing motion around the vertical axis, causing the aircraft to briefly lift off the surface. The glider subsequently impacted the ground at a 30-to-45-degree longitudinal pitch, approximately 130 meters from the takeoff point. The aircraft rotated roughly 150 degrees during the excursion.
The investigation
The BFU examined the wreckage and the mechanical condition of the flight controls. Investigators inspected the elevator control linkage and found that while some components in the securing area were bent and fractured, leading to the displacement of a clamping sleeve, this specific damage was not determined to be the cause of the accident. The investigation focused on the flight dynamics during the takeoff roll and the mechanical state of the control surfaces.
Findings
Structural damage was sustained to the forward fuselage and the tail section, and the cockpit canopy was destroyed. One person on board sustained minor injuries, specifically lacerations to the head. The investigation established that the primary cause of the accident was the left wing touching the ground during the takeoff roll, which triggered the subsequent ground loop and impact.