On August 23, 1997, about 1500 Alaska daylight time, a tundra tire equipped Helio H-295 airplane, N6465V, crashed during takeoff from a remote area of river, about 78 miles north of Fort Yukon, Alaska. The airplane was being operated as a visual flight rules (VFR) on-demand passenger flight, under Title 14 CFR Part 135, when the accident occurred. The airplane, operated by Wright Air Service Inc., Fairbanks, Alaska, sustained substantial damage. The certificated airline transport pilot, and 2 passengers, were not injured. Visual meteorological conditions prevailed. A VFR flight plan was filed. The flight originated at the Arctic Village Airport, Arctic Village, Alaska, about 1300. The operator reported the pilot was departing a 1,000 foot long gravel bar in a southbound direction. The area, located along the Sheenjek River, had been used by the operator in the past, and the pilot was picking up two passengers from a river float trip. During the takeoff run, the airplane had just attained flying speed. Suddenly, the airplane veered to the right, and the tail struck a tree along the edge of the gravel bar, jamming the stabilator. The airplane lifted off the ground, and attained a nose high pitch attitude. The pilot pushed forward on the flight controls, but was unable to lower the nose of the airplane. The airplane climbed to about 100 feet above the ground, and then descended toward the river. The airplane collided with the river, and came to rest in about 3 feet of water. The airplane received damage to the right main landing gear, stabilator, fuselage, and engine.