What happened
On June 21, 2010, at approximately 18:05, a Schempp-Hirth Janus CT motor glider, registration F-CGQK, was participating in a competition flight near Savines-le-Lac. The flight began earlier that afternoon when the front-seat pilot departed from Mont-Dauphin accompanied by a more experienced pilot in the rear seat. Due to weak thermal activity and difficult flying conditions, the rear-seat pilot took control of the aircraft.
As the aircraft lost altitude, the crew decided to divert toward the Crots ultralight airfield to land, as they were uncertain they could return to their original destination. While flying near an eastern ridge at approximately 1,25 to 1,320 meters, the crew attempted to utilize the terrain to regain altitude. After performing two maneuvers across the ridge, the pilot initiated a left-hand spiral dive, believing there was sufficient altitude margin. During this maneuver, the aircraft encountered descending air currents, causing the glider to descend too low relative to the terrain. To avoid an autorotation, the pilot reduced the bank angle, but realized a collision was unavoidable. Two seconds before impact, the pilot pulled back on the controls to reduce the impact angle, but the aircraft struck trees. The front-seat pilot sustained serious injuries, and the aircraft was destroyed.
The investigation
The investigation focused on the crew's decision-making process and the aerodynamic circumstances during the final maneuvers. Investigators examined the flight path, the meteorological conditions—which included light winds and weak thermals—and the pilot's assessment of the terrain. The investigation also reviewed the crew's change in strategy, moving from an intended landing at Crots to an attempt to regain altitude using the ridge, and how this shift impacted the pilot's concentration and situational awareness.