Beech 76 N6697L accident near Rio Linda, California

Probable cause

A loss of engine power due to carburetor icing, and the pilot's failure to use carburetor heat during descent while operating in an area conducive to carburetor icing.

NTSB analysis

According to the pilot, he began his descent from 3,000 feet mean sea level (msl) by lowering the landing gear and reducing the power on both engines. When the airplane reached an altitude of about 1,200 feet msl, the left engine lost power. The pilot was about to feather the left propeller when engine power was momentarily restored followed by both engines losing power. He selected a “dark space” on the ground and performed a forced landing. During the landing, the airplane collided with a ditch and a fence.

Postaccident examination of the engines revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. About the time of the accident, a weather station about 4 nautical miles from the accident site reported a temperature of 52 degrees F and dew point of 45 degrees F. These weather conditions were conducive to the formation of serious carburetor icing at cruise and glide power settings. The pilot did not report applying carburetor heat when he initiated the descent, during descent, or following the loss of engine power. Additionally, the pilot stated that he believed carburetor icing caused both engines to lose power.

Text from the NTSB. Open the NTSB docket for WPR12LA128 for the full record.