Cessna 185 N520YH accident near Prineville, Oregon

Probable cause

A total loss of engine power due to fuel starvation, which resulted from the pilot inadvertently leaving the fuel selector set to the left tank. Contributing to the accident was the pilot’s deviation from his normal habit pattern and his failure to refer to the in-flight engine failure checklist after the engine power loss.

NTSB analysis

During the descent to the destination airport, when the airplane was about 10 miles out and descending through about 6,500 feet, the engine experienced a total loss of power. In response to the power loss, the pilot manipulated the throttle, mixture, and propeller controls, but the engine did not regain power. When the pilot recognized that the airplane would not be able to reach the destination airport, he conducted a forced landing on an unpaved road. During the landing roll at a groundspeed of about 10 mph, the airplane struck some vegetation, and it then nosed over onto its back.

The pilot reported that, at the time of the engine power loss, the electronic fuel flow instrument indicated that 16 gallons of usable fuel was remaining, which he believed was sufficient fuel for about 1 more hour of flight and to reach the destination airport. During recovery, the fuel tanks were observed to contain about 16 gallons of total fuel, and the fuel selector handle was found set to the left tank. However, it was determined that some fuel had migrated from the fuller right tank to the nearly empty left tank via the tank vent line while the airplane was inverted. The pilot stated that his typical habit was to operate the airplane with the fuel selector set to the "both" position, but that, at some point during the flight, he had moved the fuel selector to the left tank to correct a fuel imbalance with the intention of resetting it to the "both" position once the imbalance had been corrected. The pilot reported that he realized that he had forgotten to reset the fuel selector to the "both" position and that this caused the power loss. The pilot reported that he did not manipulate the fuel selector handle after the power loss because he did not believe that he had a fuel problem and that he did not refer to any emergency checklists. The Pilot's Operating Handbook contained an engine failure during flight checklist, which included the step to place the fuel selector valve in the "both" position, which the pilot did not do.

Text from the NTSB. Open the NTSB docket for WPR12LA023 for the full record.