What happened
During the landing rollout, the captain experienced an asymmetrical deployment of the thrust reversers, which caused the aircraft to veer off the runway. The aircraft touched down on the centerline approximately 1,200 feet beyond the runway threshold. Upon moving both thrust levers into the reverse position, the airplane began yawing to the right. In an attempt to maintain directional control, the captain moved the #1 thrust lever out of reverse but inadvertently placed it in the Take-Off/Go-Around (TOGA) position, while the #2 thrust lever remained in full reverse.
The resulting thrust asymmetry—with the left engine at TOGA power and the right engine in full reverse—produced significant right yaw forces that the crew could not adequately compensate for using rudder and brake inputs. The aircraft veered off the side of the runway onto the dirt infield, causing the nose gear strut to collapse and damaging the forward fuselage. The aircraft slid to a stop approximately 7,650 feet from the threshold. There was no fire and there were no injuries.
Several days prior to the flight, maintenance personnel had rendered the #1 thrust reverser inoperative and mechanically locked it in the stowed position. Following approved Minimum Equipment List (MEL) procedures, the aircraft continued service with a placard placed next to the engine's thrust lever noting the status of the #1 reverser. While the inbound crew briefed the captain on this status at the departure airport, the captain did not include this information in his approach and landing briefing to the first officer.
The investigation
The investigation included an evaluation of the maintenance, repair history, and functionality of various directional control components. This included the brake system, the nose landing gear strut and wheels, the antiskid system, the thrust levers and reversers, and the throttle control unit. No discrepancies were found regarding these components.