What happened
On 31 December 2022, a J300 Joker microlight, identified 63ACL, was conducting a local private flight near Sardon, France. The pilot and a passenger departed from the Sardon private microlight strip at 14:40, heading toward the Chaîne des যাইতেছে Puys volcano range. After flying over Volvic at approximately 2,500 ft, the pilot attempted to climb to 2,850 ft while approaching the foothills of the mountain range at an altitude of roughly 500 ft.
Upon approaching the terrain, the aircraft entered an area of intense turbulence. In an attempt to find smoother air, the pilot initiated a descent. However, a sudden wind gust destabilized the aircraft, forcing it into a sharp right turn. The pilot was unable to recover control, and the aircraft struck the ground in a field near the hamlet of Égaules. The impact resulted in one fatality and one severe injury.
The investigation
The investigation examined the wreckage at the accident site, noting that the aircraft struck the ground in a nosedown attitude, impacting with the propeller, right main landing gear, and right wing tip before performing a U-turn. While the fuselage was ruptured and the cockpit was distorted, the flight control linkages remained continuous, and no engine or control anomalies were reported by the pilot prior to the event.
Meteorological analysis by Météo-France revealed that the region was experiencing a strong south-westerly flow. The area east of the Chaîne des Puys was downwind of the mountains, creating a zone of disturbed air and moderate turbulence that intensified closer to the ground and the eastern slopes.
Findings
- The pilot's flight path placed the aircraft downwind of the terrain, exposing it to significant atmospheric disturbance.
- The pilot's decision to descend to avoid turbulence was counterproductive, as the turbulence increased in intensity at lower altitudes near the mountain slopes.
- The pilot's understanding of the local aerological conditions was incomplete, as his weather assessment was based on broader regional data for Clermont-Ferrand rather than the specific microclimate of the volcano range.
- A sudden wind gust caused the aircraft to enter an unrecoverable steep right bank, leading to the collision with the ground.