Amateur-built RV 8 N800PB accident near Hilliard, Florida

Probable cause

A total loss of engine power due to oil starvation.

NTSB analysis

The pilot was on a cross-county flight back to his home airport. About an hour into the flight, a witness standing in her front yard, heard the airplane flying overhead and heard the engine “popping” like it was back firing. She looked up at the airplane and saw that it was “very low,” at an estimated altitude of 500 ft above ground level. The airplane disappeared behind trees and she heard the airplane hitting tree branches shortly afterward.

Examination of the airplane revealed that the fuselage and instrument panel was consumed by fire. Smoke striations from the cowling into the cockpit were consistent with an in-flight fire that originated in the engine compartment. Flight control continuity was confirmed from the flight controls to the flight control surfaces. A large hole was observed at the No. 2 cylinder case half and all of the connecting rod bearings were worn and oil starved. The No. 2 connecting rod was the most worn and the rod and cap exhibited lubrication distress. The condition of the No. 2 connecting rod bearing indicated that it was closest to the initiation point of oil starvation. However, a reason for the oil starvation could not be determined. It is likely that the inflight fire was the result of the engine failure.

Autopsy of the pilot indicated that he had cardiomegaly and moderate atherosclerotic disease. While these conditions increase the risk for having a sudden cardiac event, there was no evidence of any acute processes on autopsy and the pilot was able to extricate himself from the plane. Thus, it is unlikely that the pilot’s cardiovascular condition was a factor in this accident.

Carboxyhemoglobin was detected in the pilot’s blood at 15-16% and soot material was found in his airways. Toxicology testing detected cyanide, which can be produced by combustion, in his blood. Inhalation of both elements would have occurred from the in-flight fire. That the pilot extricated himself from the airplane suggests that the carbon monoxide itself was not impairing. Thus, carbon monoxide exposure, as determined by the carboxyhemoglobin level, was not a contributing factor in the accident.

Text from the NTSB. Open the NTSB docket for ERA20LA324 for the full record.