What happened
On September 24, 2017, a Robin DR400-120, registration F-GSBE, was performing a circuit flight involving landings and takeoffs at several aerodromes. Upon arriving at Rouen Vallée de Seine, the pilot approached runway 22 from the downwind leg at approximately 130 km/h. The initial touchdown and subsequent landing roll appeared normal.
During the application of power for a go-around, the aircraft suddenly veered to the left. The pilot attempted to correct the movement using the right rudder pedal, but reported that the controls felt stiff. As the aircraft continued its lateral excursion, the pilot applied the brakes, but found them to be largely ineffective. The aircraft eventually came to a stop in a drainage ditch located 75 meters from the runway centerline, resulting in heavy damage to the aircraft.
The investigation
The BEA examined the aircraft's movement during the high-power phase of the landing roll. The investigation focused on the interaction between the engine torque, the crosswind conditions, and the aircraft's weight distribution on the landing gear. The investigators also assessed the position of the drainage ditch, noting that while it was located within the regulatory limits of the runway safety area, its presence had been involved in previous runway excursions at this airfield.
Findings
- The primary cause of the excursion was the combined effect of engine torque and a crosswind, which induced a leftward yaw during the power application.
- The investigation identified the potential occurrence of "wheelbarrowing," a phenomenon where the nose gear bears excessive weight, reducing rudder effectiveness and braking capability. This may have been caused by the pilot applying forward elevator pressure, a technique the pilot noted had been taught to them for ground operations.
- The aircraft's impact with the drainage ditch was the direct cause of the significant structural damage.