What happened
An airline transport pilot was performing a maintenance operational check flight and was in the process of returning to a maintenance vendor's hangar. While taxiing across an ice covered parking area, the pilot applied power to move the aircraft up a small incline.
As the skis of the aircraft reached the top of the incline, the pilot closed the throttle and attempted to reach for the mixture control cut off. During this movement, the pilot's sleeve caught on the throttle control, which advanced the throttle to the open position. Due to the unintended increase in power, the pilot was unable to stop the aircraft, causing the left wing to strike a parked maintenance tug. The impact resulted in substantial damage to the left wing. The pilot reported that there were no mechanical anomalies with the aircraft prior to the accident.
The investigation
The investigation confirmed that there were no preaccident mechanical anomalies present in the aircraft.