CEN17LA352

The private pilot reported that, while in cruise flight, a total loss of engine power occurred. After unsuccessful attempts to restart the engine, he landed the airplane gear up in a cornfield, which resulted in substantial damage to the fuselage. Postaccident examination of the airplane revealed that the engine mixture control cable had fractured about 9 inches from its attachment point at the engine. A metallurgical examination of the mixture control cable with a scanning electron microscope revealed fracture surface features that were consistent with a fatigue failure. It is likely that the engine mixture control cable fractured in flight, which led to a total loss of engine power.

On September 13, 2017, about 1717 central daylight time, a Cessna 210G airplane, N5906F, was substantially damaged during a forced landing following a loss of engine power near Hallsville, Missouri. The private pilot was not injured. The airplane was registered to and operated by AWG Aviation LLC under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed for the flight, which departed without a flight plan from Columbia Regional Airport (COU), Columbia, Missouri, about 1704, with a destination of Washington Municipal Airport (AWG), Washington, Iowa. According to the pilot, after climbing to 3,500 ft above mean sea level, he leaned the engine's mixture. While in cruise flight, he observed a total loss of engine power and the propeller continuing to windmill. After unsuccessful attempts to restart the engine, the pilot landed, gear up, in a cornfield, damaging the fuselage. Postaccident examination of the airplane by a Federal Aviation Administration inspector revealed the engine mixture control cable had fractured about nine inches from its attachment point at the engine. The cable was sent to the National Transportation Safety Board (NTSB) Materials Laboratory for further examination. Digital microscope images of the wire strands indicated the fracture surfaces were flat and perpendicular to the axes of the strands. No necking or thinning of the individual strands consistent with overstress separation was observed. Several wires were sectioned examined using a Zeiss Auriga 40 field emission scanning electron microscope (SEM). Post separation impact damage was observed around the outer circumference of the fracture surface. Feathery features consistent with fatigue were observed on the fracture surface. The full NTSB Materials Laboratory report is available in the official docket of this investigation.