What happened
On July 17, 2017, a Centrair 101A glider, registration F-CFXC, was performing a winch launch from the unpaved runway at Laval Entrammes aerodrome. During the initial climb, the pilot requested that the winch operator increase power. While the aircraft was maintaining a significant pitch-up attitude, it began to yaw to the left. The pitch rapidly transitioned into a severe nose-down attitude, causing the glider to strike the paved runway surface almost vertically. The impact resulted in the death of the pilot and the destruction of the aircraft.
The investigation
The BEA examined the aircraft, the winch operation, and the meteorological conditions at the time of the accident. The investigation included a review of radio communications between the pilot, the winch operator, and the AFIS agent. While the aircraft's flight recorders (FLARM and GNSS) yielded no specific data for the accident flight, data from a different glider launched shortly before the accident provided context regarding wind conditions.
Testing of the winch following the accident showed that the equipment was functioning correctly, with the engine speed following the prescribed procedures for power application. Witnesses, including the AFIS agent and the winch operator, noted that the glider's pitch-up attitude was higher than normal during the initial climb and observed the cable slackening before the final descent.
Findings
- The takeoff and initial climb occurred with a strong crosswind component, though within the demonstrated limits of the aircraft's flight manual.
- The cable slackened during the initial climb, likely due to an instantaneous tailwind component.
- This slackening may have been perceived by the pilot as a drop in winch power, prompting the request to accelerate.
- The glider experienced an asymmetric stall to the left, likely caused by the combined effects of decreasing airspeed and the downward force exerted by the winch cable as it became taut again.
- The low altitude at the moment of the stall left the pilot with insufficient time to recover control of the aircraft.