NTSB Factual Report

On June 3, 2017, about 1130 Pacific daylight time, an experimental, amateur-built Sonex airplane, N255BZ, sustained substantial damage during a forced landing 1 1/2 miles south of Garfield, Washington. The private pilot was the sole person on board and was not injured. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and a flight plan was not filed for the cross-country flight. The flight originated from Felts Field Airport, Spokane, Washington, at 1025 and was destined for Pullman Moscow Regional Airport, Pullman, Washington.

The pilot reported that while in cruise flight, at 4,000 feet mean sea level, he experienced a vibration followed by a loud bang. Shortly thereafter, the propeller separated from the airplane. The pilot subsequently performed a forced landing to a paved road.

During the landing roll, the airplane impacted a power pole guy wire and the left wing sustained substantial damage.

The accident site was documented and the examination of the airplane revealed the propeller assembly and forward section of the crankshaft separated near the forward crankshaft bearing. The propeller and crankshaft section was witnessed falling into a field near the accident site. A search continues for the propeller assembly and crankshaft section.

The airplane was recovered to a secure location for further examination.