What happened
Upon completing the landing roll, the Dornier 328-100 began to veer slightly to the left. The first officer, acting as the flying pilot, applied rudder to maintain control. As the aircraft speed exceeded 60 knots, the captain assumed control of the aircraft and successfully realigned it with the runway centerline.
At a speed between 60 and 70 knots, the captain commanded the condition levers (CL) to be moved to the minimum position. Following this adjustment, the aircraft began veering left once again. The captain was unable to maintain directional control as the aircraft veered sharply to the left, causing the right propeller and the right wing tip to make contact with the runway. The aircraft subsequently collided with a runway sign before coming to a stop partially off the runway. There were no injuries reported.
The investigation
The investigation focused on the steering authority of the aircraft relative to the position of the condition levers. Under Horizon Air procedures at the time, the condition levers were to be set to maximum upon touchdown, with the captain having the discretion to move them to minimum after landing. In the maximum position, the crew had up to 10 degrees of nose-wheel steering via the rudder pedals, whereas the minimum position provided 60 degrees of steering authority through the tiller.
The Dornier 328-100 operating manual specified that at a safe speed, the condition levers should be retarded to the minimum position. Investigators found no mechanical failure or malfunction involved in the incident.