Accident to the fixed-wing G1 Aviation identified 04IF on 04/02/2023 at Salignac

Even though there were strong Mistral winds in the region, the pilot under instruction and the instructor were flying in an air mass with low turbulence since take-off from Barcelonnette Saint-Pons. The pilot had been holding an indicated airspeed above the manoeuvring speed Va for ten minutes when the air mass became rougher as they crossed the Baume mountain near the Cluse of Sisteron. The pilot and instructor continued the flight, giving themselves the option of turning around. Shortly afterwards, when the indicated airspeed was 40 km/h above the Va, the microlight suddenly entered a roll.

When the microlight banked to the right, the pilot under instruction, surprised, and to counteract this start of roll, instinctively made a sudden and large input, at least on the rudder control and most probably on the roll and pitch controls.

He lost control of the microlight, which entered a spin. The instructor took over the controls and tried to regain control of the microlight. Observing that his inputs on the controls had no effect, he quickly pulled the airframe parachute handle. This input caused the airframe parachute to open at a sufficient height, allowing the occupants to survive.

The investigation was unable to determine the exact sequence, in particular the precise moment when the wings distorted. The structural under-dimensioning of the wings brought to light during a static test conducted by G1 AVIATION as part of the safety investigation, the indicated airspeed substantially higher than the Va in rough air, as well as the sudden deflection of one or more control surfaces above this speed, were cumulative factors likely to have contributed to a structural degradation of the wings.