What happened
On June 1, 2009, during a regional gliding championship at Pasewalk, a Glaser DG 100 glider was performing a winch-less takeoff, being towed by an ultralight aircraft. During the takeoff roll, witnesses observed the glider lifting off briefly and repeatedly while still in the taxi phase. These movements were accompanied by unusual elevator behavior. As the towing aircraft gained altitude, the pilot disconnected the tow rope to terminate the takeoff attempt. Following the release, the glider accelerated at high speed across the eastern boundary of the airfield and into a grain field.
There were no injuries to the pilot, though the aircraft sustained significant damage, including the destruction of both wings.
The investigation
The BFU examined the wreckage at the accident site, located approximately 10 meters east of the airfield boundary in a field with 1.3-meter-high crops. Investigators found that both wings had suffered multiple fractures. While the landing gear was extended and the tow rope was disconnected, the investigation focused on the flight controls. Although all control linkages appeared connected, investigators identified a detached deflection lever used for the elevator control.
Findings
Technical analysis revealed that the attachment bolt for the elevator deflection lever had separated from the composite structure. The investigation determined that the attachment bolt had been laminated into the component without a required washer. This omission led to the structural failure of the mounting point during the takeoff roll, resulting in the erratic elevator movements and the subsequent loss of directional control.