What happened
On 6 August 2020, a Flight Design CTSW microlight, registration 83AGL, was performing a cross-country flight from Fréjus to the Cruis Mas des Grailles microlight strip. During the final approach to runway 35, the pilot experienced difficulties stabilizing the approach, with significant variations in engine speed recorded.
The aircraft touched down at the runway chevrons with the flaps in the 30° landing configuration. Immediately following touchdown, the pilot applied full throttle to initiate a go-around. However, the aircraft's airspeed rapidly decreased. In an attempt to regain performance, the pilot retracted the flaps to 0°. This maneuver, combined with the aircraft's low speed and high angle of attack, led to a stall at an altitude of approximately 12 meters. The aircraft collided with the ground, and a subsequent fire destroyed the wreckage. The pilot and one passenger were both fatally injured.
The investigation
The BEA investigation utilized data from a GoPro camera mounted in the cabin, which recorded instrument readings and GNSS flight path data. This allowed investigators to reconstruct the unstable approach and the subsequent loss of airspeed. The investigation also examined the physical wreckage, finding the engine was producing power at impact and the flight control linkages were intact, with any breaks being the result of impact forces.
Investigators also reviewed the characteristics of the Cruis Mas des Grailles strip, noting its 6% runway slope and the presence of obstacles. The investigation compared this event to a previous accident at the same strip involving an Evektor Eurostar, noting a pattern of risks associated with go-arounds on sloping terrain.
Findings
- The pilot attempted a go-around on a runway with a significant downward slope, which likely prevented the aircraft from maintaining sufficient climb performance.
- The aircraft entered a backside of the power curve situation, where the engine was at maximum power but the airspeed continued to decay.
- The decision to retract the flaps during the low-speed climb contributed to the loss of lift and the subsequent stall.
- The pilot's lack of specific training in mountain flying and landing on sloping surfaces may have influenced the decision to attempt a go-around beyond a safe point.
- The relatively non-mountainous appearance of the surrounding area may have led to an underestimation of the hazards posed by the runway slope and nearby obstacles.
Safety action
Following the accident, the microlight strip chart was updated to include specific language prohibiting go-around maneuvers beyond a designated ground marker.