History of the Flight
On 6 August 2020, a Flight Design CTSW microlight, registered as 83AGL, departed from Fréjus microlight strip (Var) at 10:48 local time for a cross-country flight to Cruis Mas des Grailles microlight strip in Alpes-de-Haute-Provence. The pilot, accompanied by one passenger, conducted a reconnaissance overflight of the destination area before joining the downwind leg for runway 35.
During the final approach, the pilot varied engine speed multiple times between 1,800 and 4,400 rpm. Touchdown occurred at the chevrons just after the runway threshold, with an indicated airspeed of 75 km/h, flaps at 30°, and a nose-up attitude of approximately 10°. In the second following touchdown, the pilot advanced the throttle to full and immediately initiated a go-around. Engine speed increased to about 5,200 rpm, but indicated airspeed rapidly decreased to approximately 45 km/h about 15 seconds after touchdown. The pilot then retracted the flaps to 0° while the attitude reached 17°. In the subsequent three seconds, control was lost, the passenger pulled on the stick, and the throttle was moved to idle. The microlight collided with the ground, and a fire broke out.
Microlight and Strip Information
Cruis Mas des Grailles is a private microlight base comparable to a mountain airstrip, located at an altitude of 690 m. It has a 300 m long grass runway oriented 17/35 with a +6% slope. The strip owner requires prior contact for authorization and instructions. The BASULM sheet notes frequent strong downdrafts in summer.
The CTSW is a fixed-wing microlight with a ROTAX 912 ULSFR engine and an emergency ballistic parachute. Flaps are controlled by a multi-position selector with a range of -12° to +38°. The recommended landing flap position is between +15° and +38°. Stall speeds at maximum weight are specified as 85 km/h with flaps at -12°, 75 km/h with flaps at 0°, and 64.9 km/h with flaps at +38°. The microlight has no stall warning system.
Meteorological Conditions
Météo-France estimated conditions at 11:45 as a southerly wind of 3 kt gusting to 8 kt, CAVOK, QNH 1,017 hPa, and a temperature of 28 °C. The situation was not considered conducive to downdrafts at the accident site.
Examination and Recorded Data
The wreckage was located approximately 250 m beyond the north end of the runway (threshold 17). The structure was completely burned by the post-impact fire. Examination indicated the microlight was intact at ground contact with low horizontal speed, a nose-down attitude, and a right bank angle. Flight control linkages showed no discontinuities outside fire-damaged areas; breakages were caused by overload from impact. The engine was operating at impact and supplying power. The emergency ballistic parachute system had been triggered, likely by the fire.
A GoPro camera held by the passenger recorded instrument panel data during the minutes leading to the accident. Analysis showed an unstabilized approach with significant engine speed variations. The data also indicated the climb slope during takeoff from Fréjus was approximately 7% with flaps at 15°.
Conclusions
The BEA concluded that the pilot, probably landing at the strip for the first time, encountered difficulties stabilizing the approach in the presence of a tailwind component. Touchdown occurred at the aiming point with correct flap configuration and airspeed. Due to abnormal contact with the runway, the pilot decided to go around despite the slope. During the go-around, flaps initially remained extended in the landing configuration, and the pilot lacked sufficient power to maintain speed and achieve an adequate climb slope. The microlight entered a backside-of-the-power-curve situation with low speed and high angle of attack. Retraction of the flaps likely to increase speed led to a stall at a height of approximately 12 m. The passenger's input and throttle reduction occurred during the loss of control. The subsequent collision with the ground and fire resulted in fatal injuries to both occupants.