What happened
On 9 October 2022, a pilot and one passenger were flying an amateur-built gyroplane, identified as 31XL, on a local flight departing from the Bois de la Pierre microlight strip in Haute-Garonne. While flying south of Saint-Élixt-le-Château at an altitude of approximately 200 meters, the aircraft experienced a sudden descent of between 50 and 100 meters. During this sequence, the aircraft turned sharply to the left. The main rotor blades made contact with the pusher propeller, causing debris to be shed and resulting in a loss of control. The gyroplane subsequently collided with the ground near a body of water, resulting in two fatalities and the destruction of the aircraft.
The investigation
Investigators examined the wreckage at the accident site, noting that debris was distributed over a 90-meter perimeter. The investigation focused on the condition of the rotor head and the propulsion system. While the engine was found to be transmitting torque at the time the propeller blades were destroyed, no mechanical malfunctions were identified within the engine or its associated systems.
Examination of the rotor blades revealed significant damage, including cuts and marks consistent with contact with the rotor head controls and the pusher propeller. The investigation also noted that the rotor starting ring gear was warped and the control arm was distorted, which prevented the main rotor from turning normally during the accident sequence. Additionally, the rudder detached from the tailplane in flight, a failure likely caused by the high torque generated during the accident sequence. The investigators also considered the possibility that an external element or a foreign object may have struck a rotor blade, though this could not be definitively confirmed.
Findings
- The primary cause of the accident was the erratic movement of the main rotor blades during flight.
- This instability led to the rotor blades striking the pusher propeller, causing sudden rotor braking and a sharp yaw to the left.
- The resulting structural forces and loss of control made it impossible for the pilot to avoid the ground impact.
- The investigation could not determine the specific origin of the rotor blade instability, though an impact with a foreign object remains a possibility.