Aircraft Accident/Incident Report

Index, Washington 98256
Thursday, April 13, 1995 17:05 PDT

While en route, the pilot advised ATC that he was picking up carburetor ice, did not seem able to get rid of it, and could not maintain his assigned altitude of 14,000 feet. He was cleared to 10,000 feet, and about 2 minutes later reported that he had virtually no power left and could not maintain 10,000 feet. He was advised that he was in 10,000-foot terrain. In response to an ATC query, the pilot reported that he was trying the carburetor heat but when he applied it the engine lost what little power it was producing. The airplane subsequently impacted steep snow-covered terrain about 100 feet below the top of a rock ridge. The pilot had earlier reported that he was picking up a trace of rime ice. During his weather briefing, the pilot was advised that the forecast for his route included occasional moderate rime or mixed ice in clouds and precipitation between 4,000 and 12,000 feet. The briefing included the fact that a moist unstable air mass, with cloud tops to 20,000 feet, would be approaching western Washington in the late afternoon.

the pilot's continued flight into known adverse weather, and his improper use of carburetor heat. Factors include: weather conditions conducive to carburetor icing and airframe icing, airframe ice, and mountainous/hilly terrain in the area of the forced descent.