Amateur-built RV6 N164BF accident near Hartford, Kentucky

Probable cause

A loss of engine power due to fuel contamination as a result of the pilot/owner's inadequate maintenance of the airplane's fuel system, which resulted in blockage of the fuel lines and filters.

NTSB analysis

The pilot/owner/builder stated that the airplane was in cruise flight at 7,000 feet mean sea level when he moved the fuel selector from the left main tank to the right auxiliary tank. The engine ran for a short time before it "stumbled," and lost power. The pilot’s efforts to restart the engine were unsuccessful, so he elected to shut off the fuel and perform a forced landing to a road. During the landing, the airplane struck a guardrail. Postaccident examination of the airplane revealed that several fuel system components and screens were partially or fully occluded with particles that resembled rust and material with the appearance, odor, and consistency of varnish. According to the pilot, his use of the auxiliary tanks was intermittent, and he had serviced them with fuel just prior to departing on the accident flight. He further explained that the varnish material from the right auxiliary tank had completely occluded the fuel line, filter, and "blocked all fuel supply to the engine," which resulted in a total loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA11LA418 for the full record.