Accident Overview
On June 10, 2021, at approximately 2058 Pacific daylight time, a Cessna 172S airplane, registration N513WF, was substantially damaged during a forced landing near Yelm, Washington. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91. Neither the pilot nor the passenger sustained injuries.
Events Leading to the Accident
The pilot reported that while cruising at about 3,500 feet mean sea level, the engine suddenly lost power. The pilot transmitted a mayday call and attempted to restart the engine. Initially, he considered landing at Western Airpark (6WN) in Yelm, located roughly 2 miles southeast of his position. However, he was unable to restart the engine and could not reach the airpark. He then opted to land in a cattle pasture short of the airpark. During the landing, the airplane nosed over.
Pilot’s Observations
The pilot stated he did not know why the engine lost power. He noted that the fuel selector valve was in the “BOTH” position, the mixture control was set to rich, and the throttle lever was in. There was no adverse weather. The airplane was equipped with a fuel-injected engine, and no issues had been encountered earlier in the flight. The pilot also indicated the airplane had about 30 gallons of fuel.
Postaccident Examination
A detailed examination of the airframe and engine found no evidence of mechanical damage to the engine. The engine could be manually rotated via the propeller, and rotational continuity was confirmed throughout the engine, valve train, and accessory section. Engine timing was verified as appropriate. The right magneto produced spark on all ignition leads; the left magneto was fitted with an electronic ignition system. The top spark plugs were removed and exhibited normal wear. Fuel system continuity was traced from the main fuel tanks to the engine fuel injection nozzles. Fuel tested negative for water, and the fuel pump was operational.
An external fuel tank was attached, and the engine was run for approximately 10 minutes at various power settings. A magneto function check showed a decrease of about 50 rpm when operating on either the left or right magneto. When the throttle was fully advanced, the engine achieved about 2,300 rpm. Overall, the examination revealed no mechanical anomalies that would have prevented normal operation.