Circumstances
The pilot completed three circuits at Sorigny on runway 22. Afterwards, another pilot boarded and took the left seat for a flight to Tours Val de Loire. At Tours, that pilot disembarked and the first pilot returned alone to Sorigny. On the return flight, the pilot joined the downwind leg for landing on runway 22. He noted wind from the right. Just before the flare, he applied left rudder to align the aircraft with the runway centerline. The main wheels touched first, and when the nose wheel contacted the runway, the aircraft immediately veered to the right. Despite applying left rudder, the pilot could not prevent a runway excursion. The aircraft came to rest in a hedge approximately 40 meters from the runway edge and about 300 meters from the displaced threshold.
The pilot estimated the crosswind at about 15 knots based on information from the Tours Val de Loire controller. He did not feel any turbulence or gusts and did not reference the windsock during his approach. He stated that a crosswind of about 15 knots during landing was not particularly difficult for him. After leaving the runway, the aircraft rolled on wet grass, making braking ineffective.
Weather observations from Tours Val de Loire reported: at 10:00 (during circuits), wind 280° at 13 knots; at 12:00 (during landing at Tours), variable wind from 270° to 330° at 12 knots; at 13:00 (time of the event), variable wind from 270° to 330° at 15 knots with gusts to 27 knots. The demonstrated crosswind limit for landing in the aircraft flight manual was 22 knots.
Pilot Information
The pilot held a private pilot license for airplanes since 1989 and a ULM license since 1990. He had approximately 860 hours of flight time in ULM and 265 hours in airplanes, including 3 hours and 45 minutes in the preceding three months.
Aircraft Nose Wheel System
On the Robin DR400, the nose wheel is connected to the rudder when the shock absorber is compressed (on the ground). In flight, when the strut is extended, the nose wheel is automatically locked in the longitudinal axis of the aircraft.
Conclusion
The BEA investigation could not formally establish the causes of the runway excursion. It noted that the following may have contributed to the accident: the lack of updating wind conditions during the approach and insufficient pilot actions to unlock the nose wheel. The BEA also referenced a study on general aviation runway excursions that specifically addresses nose wheel locking on Robin aircraft.