What happened
The captain reported that he was instructed to expedite the takeoff due to traffic on short final. To comply, he advanced the throttles to partial power for a rolling takeoff. Shortly after, the aircraft's nose wheel crossed the centerline of the runway to the right. The captain corrected by applying left nose wheel steering. However, as the nose wheel returned to the centerline, he attempted to steer it back to the right, but the aircraft did not respond. The nose continued to move left while airspeed increased and power remained set.
The captain placed both hands on the nose wheel steering control, but it would not move. He then ordered the first officer to reduce power. Despite applying full right rudder and braking, the captain was unable to stop the aircraft before it left the runway. During a subsequent ferry flight for inspection, the co-pilot stated that the nosewheel steering, brakes, and thrust reversers all operated normally.
The investigation
The investigation focused on the mechanical integrity of the steering system following the incident. A ferry pilot reported that during the post-incident transit, the nosewheel steering functioned without issue. This suggests the failure was likely intermittent or specific to the conditions of the initial takeoff roll.