Accident Description
The pilot reported that the accident occurred during a takeoff on bumpy muskeg/tundra. The takeoff was conducted downslope and downwind with full flaps deployed. At an indicated airspeed of approximately 40 to 45 miles per hour, the aircraft became airborne before reaching the edge of a deep ravine. The pilot initiated a shallow left turn, during which the left wing collided with a tree. The impact caused the aircraft to spin approximately 180 degrees from its original heading. After the spin, the aircraft was about 200 feet above the terrain inside the ravine. The pilot then lowered the nose and applied full throttle. Just before the subsequent impact, the nose was raised to a level attitude. The pilot stated that he did not see the tree and that there were no preimpact or mechanical irregularities.
Aircraft Equipment
The aircraft was noted to be equipped with non-standard wheels described as automobile racing slicks, approximately 33 inches in diameter.
Environmental Conditions
Wind conditions at the time were reported as from 180 degrees at 5 knots, gusting to 10 knots.