The pilot reported that, during the descent to the destination airport in Ashland, Mo., the Cessna 414’s left engine experienced a partial loss of power.
He attempted to troubleshoot the issue. Unable to restore the engine power, he secured the left engine, feathered the propeller, and advised air traffic control of the situation.
Shortly after, the right engine experienced a partial loss of power and eventually only produced idle power. Unable to reach the destination airport, he conducted a forced landing to a field.
A post-accident examination revealed ice buildup in the fuel manifold valves, the fuel strainer bowls, and the fuel strainer screens. The left fuel strainer bowl contained a 1-3/8-inch thick piece of ice.
Fuel samples from both of the airplane’s fuel tanks and from the fuel supplier at the airport used to the fuel the airplane earlier in the day were tested, and no water contamination was found.
The source of the water contamination could not be determined. It is likely that the loss of engine power resulted from water contamination and subsequent ice buildup in the fuel system.
The NTSB determined the probable cause as the in-flight failure of both engines due to water contamination.
NTSB Identification: CEN14LA120
This January 2014 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.