SEA97LA205

The pilot departed from an airport at which the density altitude was approximately 8,500 feet. Because winds were gusting to 15 knots from the west, and because the airport was situated in a valley just east of some 11,000 foot peaks, there were terrain-induced downdrafts and unfavorable winds present at the time of departure. Soon after takeoff, the aircraft, which was loaded to within 120 pounds of maximum allowable gross weight, entered an area of sinking air. The aircraft then quickly descended to just a few feet above the ground, and its airspeed dropped to about 40 m.p.h. As the aircraft continued to slow, it became obvious to the pilot that it would soon descend into the terrain, so he chose a spot in which to '...put it down.' After a successful touchdown, the aircraft rolled over soft terrain, where the nose gear sank into the ground and a wing collided with the terrain.

On September 6, 1997, approximately 1915, mountain daylight time, a Cessna U206F, N7494Q, impacted the terrain during a forced landing shortly after takeoff from Stanley Airport, Stanley, Idaho. The commercial pilot, who was the sole occupant, was not injured, but the aircraft, which was owned and operated by Stanley Air Taxi, Inc., sustained substantial damage. The 14 CFR Part 135 cargo flight, which was being operated in visual meteorological conditions, was taking off from Stanley Airport en route to Indian Creek Airstrip. The pilot was on a company VFR flight plan, and he reported that the ELT did not activate.

According to the pilot, the wind was blowing from the west at ten knots, gusting to 15 knots. Because the airport is located in a 6,500 foot high valley, with 11,000 foot peaks to the west, the gusting winds were creating terrain-induced areas of sinking air and unfavorable winds. Because of an ambient temperature of 70 degrees Fahrenheit, the pilot, whose aircraft was loaded to about 120 pounds below maximum allowable gross weight, was attempting a takeoff at a density altitude of approximately 8,500 feet. He elected to depart to the south, and then turned west toward mountainous terrain. As he turned to the north to make a downwind departure, the aircraft entered an area where the air was descending after flowing over a nearby mountain ridge. After encountering the downdraft, the aircraft sank from approximately 150 feet above ground level (AGL) to only a few feet above the ground. At the same time the airspeed dropped from 65 m.p.h. to about 40 m.p.h. Although the aircraft continued to fly in ground-effect, it would not climb, and the airspeed began to further deteriorate. As the airspeed deteriorated further, it became obvious to the pilot that the aircraft would soon descend into the terrain, so he chose an area in which to "...put it down." The pilot ultimately made a successful touchdown in a field near the airport, but during the landing roll, the nose of the aircraft sank into the soggy terrain, and the wing contacted the ground.