This November 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Cessna 170B. Injuries: 1 Fatal, 2 Serious. Location: Hanna, Utah. Aircraft damage: Substantial.
What reportedly happened: The pilot checked the weather forecast twice prior to departing on the cross-country flight. Both reports indicated that VFR conditions would prevail. The pilot took off and climbed to an altitude of 10,500 feet MSL in order to clear mountainous terrain. As the airplane approached the mountains, the pilot encountered increasing tailwinds that reduced the performance of the airplane. The pilot reported that as the airplane approached the mountain range it encountered unusually strong downdrafts, accompanied with a loss in altitude, speed, and rate of climb. The pilot determined that the airspeed became too slow for a safe turn without further loss of control or altitude, so he elected to pick out a clearing to make a forced landing. The airplane came down in a snow-covered clearing at an elevation of 9,800 feet MSL, surrounded by mountainous terrain about 150 feet from the initial touchdown point.
Probable cause: The flight’s encounter with adverse tailwinds and downdrafts in mountainous terrain that exceeded the airplane’s climb capability.
For more information: NTSB.gov