Accident Overview
On July 14, 2017, at 1330 Pacific daylight time, an experimental, amateur-built RV-8, registration N559JC, was substantially damaged during a forced landing near Spokane, Washington. The airplane was operated as a personal flight under Title 14 Code of Federal Regulations Part 91. The pilot reported minor injuries.
Pilot Report
According to the pilot, after takeoff the engine began to surge and acted erratically. He turned back toward the airport intending to make an emergency landing. Shortly thereafter, the engine lost total power, and black smoke was visible from the engine compartment. The pilot executed a forced landing to an open field, which resulted in substantial damage to the airplane.
Post-Accident Examination
Federal Aviation Administration (FAA) inspectors examined the Mazda automotive engine. Fire damage was noted throughout the engine. Debris consistent with molten foam air filter element was found in the throats of both intake openings and on the forward face of the alternator, which was located directly behind the air filter assembly. Molten debris was observed beneath and behind the intake air filter assembly, but not forward of it. The oil, coolant, and fuel hoses appeared intact. The oil and oil filter element were examined, and no metal contamination was identified. Internal continuity of the engine was accomplished by manually rotating the engine via the propeller; movement of the alternator belt at the rear of the engine was observed when the propeller was turned.
Conclusion
No probable cause was determined from the available information. The accident remains under review by the National Transportation Safety Board.