Accident Details
On August 27, 2017, at approximately 1620 Pacific daylight time, a North American Navion A airplane, registration N8695H, experienced a total loss of engine power during the initial climb after departing from Rohnerville Airport in Fortuna, California. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight, with visual meteorological conditions prevailing and no flight plan filed. The pilot, who was also the registered owner, reported departing with about 10 to 12 gallons of fuel on board.
After reaching approximately 1,000 feet above ground level, the engine lost power entirely. The pilot attempted to return to the airport but could not maintain altitude and performed an off-airport landing in a pasture about half a mile from the runway. The airplane sustained substantial damage to the firewall during the forced landing. The pilot was not injured.
Post-Accident Examination
A Federal Aviation Administration (FAA) certificated airframe and powerplant mechanic conducted a post-accident examination under the supervision of an FAA inspector. The inspection revealed that the original engine had been replaced with a Teledyne Continental Motors IO-470H engine, installed in June 2003. The spark plugs were removed from all cylinders and showed no signs of deterioration, wear, or oil/carbon fouling. Continuity was established for each magneto, which produced spark at each cylinder. A borescope inspection of each cylinder found no evidence of excessive wear, deterioration, broken rings, or broken valves.
The FAA inspector observed fuel in the left, right, and main tanks. Samples from each tank were sumped and disclosed no debris or water. Disassembly of the fuel manifold revealed a clean screen, but no fuel was visible. The mechanic removed the fuel inlet supply line to the fuel manifold and activated the electric fuel boost pump. Fuel flowed normally out of the inlet supply line from the selected tank, and all tank selections showed normal fuel flow.
Outcome
Despite the thorough examination, the reason for the loss of engine power was not determined.