On April 24, 2003, about 1615 eastern daylight time, a Cessna P206, N4624F, was substantially damaged while taxiing for takeoff at Newport State Airport (UUU), Newport, Rhode Island. The certificated private pilot was not injured. Visual meteorological conditions prevailed for the business flight. No flight plan had been filed for the flight, which was destined to Westerly, Rhode Island, and was conducted under 14 CFR Part 91. The pilot stated: "...Started engine, turned on radios, checked wing sock - showed 340 degrees at 10 - 15 kts (12 - 17 mph). I taxied slowly knowing from AWOS, the field conditions. About 50 feet up the taxiway, I felt a strong sudden buffeting from the left and tried to keep L [left] aileron down, but to no avail. Within 10 seconds, my aircraft was blown over, L [left] to R [right]. The pilot also stated: "I didn't believe that the engines on the King Air 300, N723P were running higher than idle...If I knew this was as powerful, I would have entered the taxiway to SW and taxied up 2,500 feet of main runway to R-34. Once I entered the taxiway to left to proceed to R-34, I could not prevent a 60 kt gale." When interviewed, the pilot reported that he saw the King Air with engines running and could hear the engines over the noise of own airplane engine. He said that he thought he could taxi behind the King Air, and did not realize that it was high power. The King Air 300 was being run by a mechanic. The owner of the company performing the maintenance run was seated in the back of the airplane and reported that the airplane was parked on a slight uphill incline. The mechanic had started the engines and intended to taxi the airplane to the right. He added power to the left engine to start the turn at the same time as the Cessna taxied behind him. The 1553, and 1653 weather observations at Newport State Airport recorded the winds from 300 degrees at 16 knots, with gusts to 20 knots, and winds from 290 degrees at 16 knots, with gusts to 19 knots.