What happened
On April 17, 2018, a student pilot was conducting a solo training flight at the Florac - Sainte-Énimie airfield. After completing several successful flights earlier that morning, the pilot launched via winch in a Centrair SNC34C glider, registration F-CJBL.
Following the launch, the pilot flew near the airfield, gradually losing altitude while searching for thermal lift. At approximately 14:20 local time, while performing a left turn at an altitude of roughly 110 meters, the aircraft's speed dropped near the stall threshold. Witnesses observed the glider suddenly enter a left spin with a steep nose-down attitude, eventually disappearing behind a nearby hill. The aircraft struck the ground in a field approximately 900 meters west of the runway, resulting in the death of the pilot and the destruction of the glider.
The investigation
The BEA investigation focused on the aircraft's configuration, the pilot's training progress, and the flight parameters leading to the impact. Investigators examined the wreckage, which showed the forward fuselage and cockpit were destroyed by the impact. Flight data recovered from the aircraft's Power Flarm Core unit confirmed that the aircraft's speed had dropped below the optimal approach speed and that the aircraft was in a turn with an inclination of over 30 degrees just before the loss of control.
Investigators also reviewed the pilot's training records, noting that while the pilot had mastered straight-line stalls, they had not yet trained for stalls in turns or high-bank maneuvers. Furthermore, the investigation examined the aircraft's weight and balance, specifically looking at the pilot's mass and the presence of any necessary ballast.
Findings
Several critical factors contributed to the accident:
- Improper Center of Gravity: The aircraft was flying with an aft center of gravity that exceeded the manufacturer's limits. Because the pilot's weight, including the parachute, was below the minimum required mass for the front seat, the aircraft lacked the necessary ballast (such as lead weights). This out-of-envelope configuration made the glider unstable and made recovery from a spin extremely difficult, if not impossible.
- Loss of Control: The pilot was searching for thermals, which led to a decrease in altitude and airspeed. As the aircraft entered a steep turn, the speed dropped to near-stall levels. The pilot, having not yet been trained in stall recovery during turns, likely failed to detect the onset of the stall.
- Lack of Supervision: At the time of the accident, the instructor was not in radio contact with the student, as they were momentarily out of visual range and waiting to establish communication via another aircraft's radio.
- Inadequate Weight Verification: While the instructor had asked if the pilot's weight was sufficient, the pilot's affirmative response was not verified, and the instructor did not account for the weight of the parachute in the calculation.