What happened
On April 10, 2023, during a seasonal training day at the Sarreguemines - Neunkirch aerodrome, a Schleicher ASK21 glider, registered F-CHIN, was involved in a takeoff accident during a towed instruction flight. The flight was being conducted by the Aéroclub de Sarreguemines using a DR400-180 tug aircraft, registered F-HIGM.
As the aircraft began its takeoff run on the grass runway, the tug pilot observed that the aircraft had not reached the required rotation speed. Because the tug pilot had not installed a rear-view mirror to save time, he was unable to confirm if the glider had already departed the ground. Consequently, the tug pilot requested a cable release. The instructor, who was controlling the glider during the takeoff, released the cable and immediately initiated a left-hand turn at an altitude of approximately 10 meters to land on the parallel airplane runway.
During this low-altitude maneuver, the glider entered a stall, causing the left wing and the nose to strike the ground. The impact resulted in the separation of the tail boom and caused serious injuries to the pilot in the rear seat.
The investigation
The BEA investigation focused on the circumstances surrounding the rejected takeoff and the subsequent loss of control. Investigators examined the performance of the DR400-180 on the specific runway conditions, noting that the grass runway was uneven and muddy in certain areas. The investigation also reviewed the flight preparation, finding that while the pilots had agreed on a cable release protocol in the event of speed issues, they had not established specific emergency flight paths for a rejected takeoff.
Furthermore, the investigation looked into the cockpit configuration, noting that the instructor's forward visibility was obstructed by the student pilot in the front seat. The tug pilot's decision not to perform weight and balance calculations or performance assessments, along with the absence of a rear-view mirror, were also scrutinized.