Weather and Approach
The flight crew obtained weather information for the destination airport, which indicated quartering tailwind conditions for the runway in use, with wind at 3 knots gusting to 16 knots. The crew determined the wind to be within limitations. The landing approach was normal, as indicated by cockpit voice recorder transcript and airport surveillance video. The captain, who was the pilot flying, conducted the landing.
Accident Sequence
After touchdown, the captain reported that the thrust reversers were deployed and the airplane turned sharply to the right. Remedial control inputs were ineffective in maintaining directional control. Airport surveillance video showed that about 9 seconds into the landing roll, the airplane turned sharply to its right. The airplane then departed the runway. During the excursion, its left wingtip struck the ground, and the entire wing structure, comprising the left wing, right wing, and wingbox, separated from the airplane as one assembly. The fuselage continued a short distance before coming to rest upright. The thrust reversers on each engine were deployed and their extended positions were about equal.
Investigation Findings
Surveillance video footage showed a windsock nearly parallel to the ground, indicating nearly a direct crosswind to the landing runway that would have been towards the airplane’s right side. Recorded wind shortly after the accident was consistent with a 90° right crosswind for the landing runway at 6 knots with gusts to 14 knots. A detailed examination of the airplane and system components revealed that all flight control, steering, and braking systems and their actuator components operated as designed. Although the copilot's yaw force sensor did not meet manufacturer acceptance testing during post accident examination, investigators determined that this would not have affected the directional controllability of the airplane.
Probable Cause
Based on the available information, it is likely that the pilot’s compensation for the crosswind conditions was inadequate, which resulted in a loss of directional control and runway excursion. The official probable cause was the captain’s inadequate compensation for crosswind conditions, which resulted in a loss of directional control.