What happened
On February 24, 2012, an instructor and a student were performing a winch-assisted takeoff for a dual instruction flight at Le Mazet-de-Romanin airfield. During the takeoff roll, the student pilot applied back pressure to rotate the aircraft, at which point the rear of the fuselage made contact with the ground. Following this impact, the aircraft's speed increased to approximately 140 km/h, exceeding the maximum winch-launch speed of 100 km/h specified in the flight manual.
As the instructor took control to manage the airspeed, the aircraft exhibited abnormal pitch behavior. The instructor released the winch cable at an altitude of roughly 150 meters. During the subsequent descent, the aircraft's vertical speed and airspeed continued to increase, and the instructor realized that pitch control had been lost. By deploying the airbrakes, the instructor was able to partially stabilize the trajectory. Unable to reach the runway, the crew performed a 9-degree left turn to execute an emergency landing in a nearby field. The Schleicher ASK 13, registration F-CHRK, struck the ground, bounced, and came to a halt, resulting in heavy damage to the airframe.
The investigation
Investigators examined the aircraft and discovered that the elevator had become disconnected from its control linkage. Specifically, the roller located within the elevator fitting, which interfaces with one of the control rods, had slipped out of its housing.
Comparative measurements were performed on the F-CHRK and two other gliders of the same model. The results revealed significant discrepancies, showing that the roller on the involved aircraft was positioned higher in its housing than on the other two units. This misalignment meant that even moderate control inputs were sufficient to cause the roller to dislodge from its seat. The aircraft had 6,884 flight hours and had been reassembled only eleven days prior to the accident, having flown 29 hours since its last major maintenance check.