What happened
On July 26, 2011, during a military glider competition at Holzdorf airfield, a towing operation involving a PZL-104 Wilga 35 and an ASW 15 glider resulted in an accident on the grass runway 09.
Six seconds after the tow aircraft began its takeoff roll, the glider drifted approximately 20 degrees to the right. As the glider lifted off, the longitudinal axis remained oriented to the right. Simultaneously, the tow aircraft veered sharply to the left, with the deviation angle increasing until it reached 90 degrees. Shortly after liftoff, the glider entered a steep climb, following the path of the tow aircraft.
In an attempt to recover, the pilot of the Wilga 35 initiated an aborted takeoff. During this maneuver, the PZL-104 Wilga 35 overturned, sustaining heavy damage to its structure, including a broken right main landing gear and a propeller separated at the root. The pilot of the tow aircraft escaped without injury. The glider pilot reported releasing the tow rope after the tow aircraft veered off course. The ASW 15 performed a 270-degree turn at an altitude of approximately 30 meters and landed undamaged about 100 meters from the wreckage.
The investigation
The BFU investigation utilized amateur video footage to reconstruct the sequence of events. The investigation examined the mechanical condition of both aircraft and the flight profiles of the pilots. The investigation found no evidence of technical malfunctions in either the P/ZLS-104 Wilga 35 or the ASW 15.