Cessna 150 N6617F accident near Davis City, California

Probable cause

A total loss of engine power due to water contamination in the fuel, which resulted in a forced landing and collision with terrain. Contributing to the accident was the pilot's improper decision to proceed with the flight after discovering the contaminated fuel.

NTSB analysis

The pilot and passenger performed a preflight inspection of the airplane before the accident flight, during which they discovered water in the fuel. They sumped the fuel tanks until they observed water-free fuel samples then taxied the airplane to the airport's fuel island and filled the tanks to capacity, which totaled 26 gallons. They took multiple additional fuel samples after fueling the airplane and observed more water in the tanks. They continued to sump the tanks until no water was observed.

Despite evidence of severe water contamination, the pilot elected to proceed with the flight. Once airborne, they performed touch-and-go landings at multiple airports before they returned to their home airport. During the return flight, the pilot experienced a total loss of engine power, and, after unsuccessful attempts to restart the engine, the pilot performed a forced landing in a field near their home airport. The engine mount, firewall, and rudder were substantially damaged during the accident.

Examination of the airplane found evidence of water contamination in the right-wing tank and throughout the fuel system, which likely caused the engine to lose all power. The airplane had been stored outside for several months before the accident flight, at which time rain was likely introduced into the right-wing fuel tank, which did not form a proper seal. The mechanic who recently replaced the gasket and lanyard on the left wing may have erroneously notated the incorrect fuel tank in the aircraft logbook. The pilot proceeded with the flight despite the discovery of water contamination.

Text from the NTSB. Open the NTSB docket for WPR19LA160 for the full record.