On July 28, 1999, about 1800 Alaska daylight time, a wheel equipped Cessna 172 airplane, N79169, sustained substantial damage during takeoff from the Sheldon Point Airport, Sheldon Point, Alaska. The airplane was being operated by Grant Aviation of Bethel, Alaska, as a visual flight rules (VFR) positioning flight under Title 14, CFR Part 91, when the accident occurred. The solo airline transport pilot was not injured. Visual meteorological conditions prevailed, and VFR company flight following procedures were in effect. The flight originated at the Emmonak Airport, Emmonak, Alaska, and the intended destination was Emmonak. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge on July 29, the pilot reported he was attempting to depart on runway 20. He said there was a gusty left crosswind, of about 18 knots and 90 degrees to the runway. Shortly after beginning the takeoff roll, he said a wind gust lifted the left wing, and pushed the airplane to the right, and off the runway. He said he reduced power and attempted to keep the airplane on the runway, but the airplane went off the runway, down an embankment, and nosed over. The pilot said there was no preaccident mechanical problems with the airplane. The airplane received substantial damage to the right wing and vertical stabilizer.