What happened
On August 27, 2014, at approximately 18:20, a Schleicher ASK13 glider, registration F-CDYZ, crashed into trees and terrain near Saint-André-d’Embrun, France. The aircraft was participating in a soaring competition involving a circuit of several waypoints, starting from the Mont-Dauphin Saint-Crépin aerodrome.
After completing several legs of the competition, the crew was flying the third branch of the circuit. Having departed from the Mont du Morgon at an altitude of approximately 2,450 meters, the pilots were transitioning toward the south side of the Durance valley. During this nine-minute transition, the glider experienced a steady descent at an average rate of 1.25 m/s, losing roughly 600 meters of altitude.
As the aircraft approached a mountain ridge, it briefly gained 50 meters of altitude. However, following a right-hand turn, the glider lost 30 meters of altitude within ten seconds. The aircraft subsequently struck trees with its left wing before impacting the ground in a nose-down attitude. The accident resulted in two fatalities and the total destruction of the glider.
The investigation
The investigation focused on the flight path and environmental factors at the time of the impact. Investigators established that the weather conditions were CAVOK with a light 6-knot wind from the south-southwest and a temperature of 18°C.
Technical examinations of the Schleicher ASK13 revealed no mechanical malfunctions that contributed to the accident. While the investigation could not definitively identify which pilot was in command during the various flight phases, it was noted that both pilots were experienced in mountain flying and were regular participants in the competition.
Findings
- The aircraft was flying a trajectory toward the west prior to the collision.
- The investigation noted that other pilots flying similar trajectories from the Mont du Morgon toward the eastern reliefs did not encounter significant downdraft, as they maintained a greater distance from the terrain.
- The pilots may have encountered a downdraft (rabattant) while crossing the ridge, which prompted a maneuver to avoid the terrain.
- The wreckage orientation differed from the flight path recorded by the Flarm system during the final ten seconds of flight, suggesting a significant change in direction occurred just before impact.