What happened
On 25 June 2020, a Schleicher ASK13 glider, registration F-CDYD, was conducting a local flight near Chambéry Challes-les-Eaux. The pilot, accompanied by one passenger, utilized winch launch techniques and followed mountain uplifts to reach an altitude of approximately 1,400 m. After performing a U-turn near Bagne mountain, the flight proceeded toward the Cirques de Montagnole.
Upon reaching the second cirque at an altitude of roughly 1,000 m, the glider began to lose altitude. The pilot attempted to execute a U-turn to move away from the terrain, but the aircraft was suddenly struck by a strong downdraft. Realizing a collision with the vegetation was unavoidable, the pilot issued a distress call over the air/air frequency and pulled the nose up in a final attempt to clear the treetops. The glider ultimately impacted the trees and came to rest several meters above the ground.
Following the impact, the pilot sustained injuries, while the passenger remained uninjured. Because the aircraft was obscured by dense foliage and lacked mobile network coverage, the occupants had to descend the trees and trek for approximately one hour to reach a location where they could contact emergency services.
The investigation
The BEA examined the aircraft's FLARM computer, which allowed investigators to reconstruct the flight path and confirm the altitude at the time of the incident. The investigation also reviewed meteorological data from Météo-France, which indicated a northerly wind of 3 to 5 knots and clear visibility. The pilot's experience was noted, including 1,200 flight hours in gliders. The investigation also focused on the lack of an emergency locator transmitter (ELT) and the challenges faced by rescue services in locating the wreckage due to the lack of immediate automated alerts.