What happened
On August 18, 2011, an APM 20 Lionceau, registration F-GRKA, was completing a 25-minute local flight with one passenger at the Amboise-Dierre aerodrome. The pilot approached runway 29, which is an unpaved strip, under a light crosswind of 6 knots from 190 degrees.
During the landing roll, the aircraft began to drift to the left of the runway centerline. The pilot attempted to correct the trajectory using the rudder pedals, but was unable to maintain the centerline. As the aircraft transitioned from the unpaved surface to the adjacent paved runway, the sudden increase in tire grip caused severe lateral stresses. This resulted in the collapse of the nose gear and the failure of the right main landing gear, bringing the aircraft to a halt. The aircraft sustained heavy damage.
The investigation
The investigation focused on the aircraft's movement on the unpaved surface and the mechanical failure of the landing gear. Investigators examined tracks left on the grass runway, which confirmed the aircraft was in a skid during the excursion. No technical malfunctions were found on the aircraft prior to the incident. The investigation also reviewed the pilot's experience, noting that while the pilot held a PPL(A) license, they had only accumulated two hours of flight time on this specific aircraft type, with only one hour flown in the preceding 30 days.
Findings
- The primary cause of the accident was inappropriate rudder pedal inputs during the landing roll.
- The pilot's limited experience on the aircraft type likely contributed to the loss of directional control.
- A light crosswind may have acted as a contributing factor.
- The structural failure of the nose gear and the right main gear was caused by the intense lateral forces exerted on the landing gear as the tires regained traction upon hitting the paved surface.