What happened
On the afternoon of October 2, 2011, a Schemli-Hirth Flugzeugbau Duo Discus glider, registration OH-1000, was conducting a local flight from Santa Cilia Aerodrome in Huesca, Spain. The aircraft was occupied by two crew members. While flying near Sayerri Peak in Borau, the glider's vertical stabilizer struck a griffon vulture head-on.
The impact caused the upper segment of the vertical stabilizer to detach from the aircraft, taking part of the horizontal stabilizer with it. Following the structural failure, the glider entered a sharp descent, falling at a vertical speed of up to 52 m/s. The aircraft impacted a steep hillside, resulting in two fatalities. The occupants were not wearing their safety harnesses at the time of impact, and their bodies were ejected from the cockpit upon collision with the terrain.
The investigation
Investigators from the CIAIAC utilized data from an onboard GPS logger to reconstruct the flight path, confirming the aircraft was traveling at approximately 132 km/h before the collision. The investigation focused on the wreckage of the tail assembly and the remains of a 9.55 kg griffon vulture found near the detached components. The bird exhibited a deep, vertical impact wound on its left clavicle, which matched the fracture on the aircraft's vertical stabilizer.
Analysis of the wreckage revealed that the cockpit remained largely intact, suggesting the impact with the ground occurred at a relatively shallow angle due to the sloping terrain. The investigation also noted that the canopy was open and the safety harnesses were unfastened, suggesting the crew may have been preparing to deploy parachutes before the loss of control occurred.