What happened
On August 11, 2024, a Schempp-Hirth Ventus 2cT, registration OY-XSW, was participating in a local competition flight originating from Arnborg (EKAB). Following a successful engine test of the retractable retrieval motor after takeoff, the pilot encountered weakening thermals, which necessitated an outlanding in a nearby field. The pilot identified a suitable grass strip, approximately 500 meters long, and planned a westward approach.
While maneuvering toward the landing site at an altitude of roughly 250 meters, the retrieval motor deployed unexpectedly. After several unsuccessful attempts to restart the engine and encountering unexpected sink, the pilot extended the landing gear. During the approach, the pilot observed an agricultural vehicle entering the intended landing area, making the original plan unfeasible.
Faced with the risk of continuing the approach with the deployed motor at a low altitude, the pilot attempted to land in a tractor furrow located between spruce trees, which were approximately 1 to 1.5 meters in height. The glider entered the furrow but the left wing struck the trees, causing a 120-degree groundloop that brought the aircraft to a halt. There were no fatalities, though the aircraft sustained significant damage, including cracks in the rear fuselage and wing trailing edge.
The investigation
The investigation by the Danish Accident Investigation Board focused on the sequence of events leading to the forced landing and the subsequent impact. Investigators examined the state of the aircraft, noting cracks in the left side of the fuselage, cracks near the engine mount, and delamination on the left wing. The investigation also looked into the mechanical state of the retrieval motor, noting that the pilot discovered the motor control's automatic fuse had tripped during a subsequent attempt to retract the engine.
Findings
- The primary cause of the accident was the unplanned landing in a restricted area between trees necessitated by the presence of an agricultural vehicle on the primary landing site.
- The deployment of the retrieval motor at a low altitude significantly restricted the pilot's maneuvering options and increased the risk of the landing.
- The presence of an agricultural vehicle unexpectedly entered the planned landing zone, forcing the pilot to seek an alternative, more hazardous landing site.