What happened
On April 16, 2021, a Schempp-Hirth Ventus-3T glider, registration D-KXUL, was conducting a private VFR flight near Arnborg (EKAB), Denmark. After a four-hour flight, the pilot approached the airfield to land on runway 09. The pilot intended to follow a right-hand approach, following another glider that had already landed.
During the final approach, the pilot attempted to maintain a target speed of approximately 110 km//h while managing sink rates with airbrakes. As the aircraft approached the airfield, the pilot encountered unexpected turbulence and adjusted the aircraft's pitch to maintain clearance over nearby trees. During this phase, the aircraft's indicated airspeed fluctuated significantly and eventually dropped sharply. The glider experienced a spontaneous right wing roll, likely due to a partial stall.
At an altitude of approximately 40 to 60 meters, the pilot attempted to recover the aircraft. However, due to the low altitude and a shift toward a tailwind component, a controlled off-field landing was not possible. The glider struck a hedgerow, causing the fuselage and left wing to collide with the top of the vegetation. The aircraft then hit the ground, causing it to rotate and eventually come to rest on its back.
The investigation
The investigation examined the aircraft's technical condition, the pilot's experience, and the meteorological conditions at the time of the accident. Investigators analyzed flight logger data, which revealed that the indicated airspeed had fallen below the planned 110–120 km/h range, dropping as low as 20 km/h shortly before the stall.
Meteorological data indicated north-northeasterly winds with gusts. The investigation focused on how the pilot's course correction and the changing wind components—specifically a decreasing headwind or increasing tailwind—contributed to the loss of airspeed. The investigation also reviewed the aircraft's configuration, noting the use of flaps in the +2 position and the use of airbrakes.
Findings
- Low airspeed, likely combined with a decreasing headwind component, led to a partial stall of the right wing during the final approach.
- The right wing was particularly susceptible to the stall because it was partially shielded from the airflow by the fuselage.
- The pilot's focus on navigating around trees and managing turbulence likely prevented the timely detection of the decaying airspeed.
- Low altitude and the presence of a tailwind during the recovery phase made a controlled landing in the available fields impossible.
- The aircraft's structure and the soft ground surface helped mitigate the impact forces, resulting in only minor injuries to the pilot.