On July 14, 2017, at 1330 Pacific daylight time, an experimental, amateur-built RV-8, N559JC, was substantially damaged when it was involved in an accident near Spokane, Washington. The pilot received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that, after takeoff, the engine began to surge and “acted erratically.” He turned back toward the airport to make an emergency landing. The engine then lost total power and black smoke was visible from the engine compartment. The pilot made a forced landing to an open field, resulting in substantial damage to the airplane.

Federal Aviation Administration (FAA) inspectors examined the Mazda automotive engine. Fire damage was noted throughout the engine, with some debris 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. The debris was consistent with molten foam air filter element. The oil, coolant, and fuel hoses appeared intact. The oil and oil filter element were examined with no metal contamination identified. Internal continuity of the engine was accomplished by manual rotation of the engine via the propeller; movement of the alternator belt at the rear of the engine was observed when the propeller was turned. The FAA inspectors reported that molten debris was beneath and behind the intake air filter assembly, but not forward of it.