The pilot reported that he was on a local flight in mountainous terrain near Durango, Colorado, in a Cessna 150.
While returning to the airport he began a descent by reducing power to about 60%, which resulted in a complete loss of engine power.
The pilot applied full carburetor heat and full throttle and the engine regained power. He continued a shallow descent with full throttle and carburetor heat for about another five minutes.
He closed the carburetor heat and continued the descent at 75% engine power. Within less than a minute, the engine lost complete power again.
The pilot applied carburetor heat and full throttle, along with mixture adjustments and pumping the throttle, but the engine did not restart.
He attempted a forced landing to a local highway. During the final approach, he avoided power lines by flying under them, but he was unable to flare the airplane before touchdown. The nose strut assembly sheared off during the landing and the right wing struck an embankment, which resulted in substantial damage.
The weather conditions at the time of the accident were conducive to serious carburetor icing during a descent.
Probable cause: The total loss of engine power due to carburetor icing.
NTSB Identification: CEN15CA236
This May 2015 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.