What happened
On September 22, 2015, a Schempp Hirth Duo Discus T glider, registration OH-888, was involved in an accident near Berdún, Huesca. The flight began with a winch launch from the Santa Cilia aerodrome at 14:23 local time. After being released at an altitude of 1,630 meters, the aircraft climbed to a maximum altitude of 1,701 meters while searching for thermal currents.
During the flight, the aircraft began a continuous descent. At approximately 14:56, the pilot deployed the engine to attempt to maintain altitude. However, the aircraft continued to lose height at a rate of approximately 1.4 meters per second. Realizing that altitude was insufficient to complete a standard landing circuit, the pilot attempted an emergency landing in a field approximately 11 km west of the aerodrome. During the final approach, the right wing struck a group of trees, causing the aircraft to rotate and impact the ground. Both occupants sustained minor injuries.
The investigation
The investigation focused on the sequence of events leading to the loss of altitude and the circumstances of the impact. Investigators analyzed data from a FLARM GPS-based collision avoidance system, which provided a precise reconstruction of the flight trajectory, altitude, and vertical speed.
Technical examination of the wreckage revealed that while the engine had been deployed from its fuselage compartment, the ignition switch was found in the OFF position. The investigation also examined the pilot's actions regarding the engine start checklist and the aerodynamic impact of the deployed, non-functioning engine.