On February 3, 1999, about 1030 Alaska standard time, a ski equipped Piper PA-18-150 airplane, N7875D, sustained substantial damage while taxiing at Lake Hood, Anchorage, Alaska. The airplane was being operated as a visual flight rules (VFR) local area flight when the accident occurred. The airplane was operated by the U.S. Department of Interior, on a public use mission. The solo airline transport pilot was not injured. Visual meteorological conditions prevailed, and VFR company flight following procedures were in effect. In his written statement to the National Transportation Safety Board, the pilot reported that he was returning to a maintenance vendor's hangar after completing a maintenance operational check flight. He said that while taxiing on an ice covered parking area, he applied power to taxi up a small incline. He said that as the airplane's skis went over the top of the incline, he closed the throttle, and reached for the mixture control cut off. He noted that his sleeve caught on the throttle control, advancing it to the open position. He said that he was unable to stop the airplane, and the left wing struck a parked maintenance tug. The left wing sustained substantial damage. The pilot noted that there were no preaccident mechanical anomalies with the airplane.