History of Flight
On October 28, 2011, about 1350 Pacific daylight time, a Cessna 185, registration N520YH, was substantially damaged during an off-airport forced landing near Prineville, Oregon, following a complete loss of engine power. The owner/pilot and the two passengers were not injured. The personal flight was operated under 14 CFR Part 91 in visual meteorological conditions; no flight plan was filed.
The flight originated from a private airstrip in central Idaho with a destination of Bend Municipal Airport (BDN) in Bend, Oregon. The pilot estimated the departure fuel quantity at 57 gallons. The cruise portion was conducted at 10,500 feet under visual flight rules without ATC services.
About 2.5 hours after takeoff, the pilot began a descent for BDN by reducing power to 20 inches of manifold pressure and adjusting the mixture as required. When the airplane was approximately 10 miles from BDN and descending through about 6,500 feet, the engine suddenly ceased developing power. At that time, the electronic fuel flow instrument indicated sufficient fuel for about one more hour of flight.
The pilot manipulated the throttle, mixture, and propeller controls, but the engine did not restart. He did not manipulate the fuel selector or activate the fuel boost pump. The pilot committed to a forced landing on an unpaved road in a wilderness area. The landing was uneventful until the airplane nearly stopped, when it struck vegetation and nosed over onto its back. The pilot shut down the airplane, and all occupants exited through the pilot's door. The pilot used a mobile phone to call for assistance.
Aircraft and Personnel Information
The pilot held an airline transport pilot certificate with instrument, single-engine, and multi-engine land ratings. He reported about 3,800 total flight hours, including 830 hours in the accident make and model. His most recent FAA third-class medical certificate was issued in July 2008, and his most recent flight review was completed in October 2011.
The airplane was manufactured in 2006 and equipped with a Teledyne Continental Motors IO-550 series engine. As of its most recent annual inspection in November 2010, the airplane had accrued 8,131 total hours. The pilot estimated the engine had accumulated about 200 hours since overhaul. The airplane had an electric fuel boost pump used for starting, normally kept off in cruise, and was equipped with a JPI fuel flow indicator and engine monitor.
Meteorological Information
The 1355 automated weather observation at an airport about 10 miles west-southwest of the accident location reported winds from 210 degrees at 9 knots, visibility 10 miles, clear skies, temperature 17°C, dew point -12°C, and altimeter setting 30.07 inches of mercury.
Engine Monitor Data
The engine monitor was extracted and sent to the NTSB Recorders Laboratory in Washington, DC. The data were successfully downloaded and revealed no operational abnormalities. About 2 minutes and 10 seconds before the end of the data, exhaust gas temperature (EGT) values rose temporarily, then EGT and cylinder head temperature values began rapid, smooth, continuous decreases. The temporary EGT rise preceding the decrease was consistent with engine shutdown by fuel starvation.
Wreckage Examination
The airplane came to rest inverted on the unpaved two-track road. The cowl, right wing strut, vertical stabilizer, and rudder were damaged by the nose-over. No fuel leaks were observed. The four-position (LEFT, RIGHT, BOTH, OFF) fuel selector handle was found set to LEFT. When the airplane was righted the next day, the left fuel tank contained about 6 gallons and the right tank about 10 gallons. The wing tanks were interconnected with a vent line near the top, which could permit fuel migration from the fuller tank when inverted.
Additional Information
In his written statement, the pilot reported that just before the power loss, the fuel flow device indicated 58 gallons consumed since refueling, leaving about 16 gallons usable. He estimated being about 5 minutes from the destination and believed he had sufficient fuel. He did not refer to any emergency procedures checklists after the power loss. The third entry in the "Engine Failure During Flight" checklist in the Pilot's Operating Handbook was "Fuel Selector Valve – BOTH."
The pilot stated it was his habit to operate with the fuel selector in the BOTH position. After the accident, seeing the selector set to LEFT, he recalled moving it from BOTH to LEFT during the flight to correct a fuel imbalance, intending to reset it to BOTH once corrected. He realized he likely forgot to reset it, and that was the likely cause of the power loss.