WPR21LA303

While en route about 3,500 ft mean sea level, the airplane’s engine lost power. The pilot attempted to restart the engine unsuccessfully and made a forced landing in a pasture. During the landing, the airplane nosed over, which resulted in substantial damage. The pilot reported that he did not know why the engine lost power. He stated that the fuel selector valve was in the “BOTH” position; the mixture control was set to rich; the throttle lever was in; and there was no adverse weather. He further stated the fuel-injected engine had no issues during the earlier portion of the flight and that the airplane had an adequate supply of fuel. Postaccident examination of the airframe and engine revealed no evidence of mechanical damage to the engine. The engine was successfully run at various power settings for about 10 minutes. A functional check of the magnetos showed an appropriate decrease of about 50 rpm when operating on either the left or right magneto. When the throttle was advanced to the full forward position, the engine’s rpm was about 2,300. Overall, the examination revealed no evidence of any anomalies that would have precluded normal operation of the airplane. The investigation was unable to determine the reason for the loss of engine power from the available evidence.

On June 10, 2021, about 2058 Pacific daylight time, a Cessna 172S airplane, N513WF, was substantially damaged when it was involved in an accident near Yelm, Washington. The pilot and the passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that while en route about 3,500 ft mean sea level, the airplane’s engine suddenly lost power. The pilot radioed a mayday call, attempted to restart the engine, and initially considered landing at Western Airpark (6WN) Yelm, Washington, located about 2 miles southeast of his position. However, he was unsuccessful in restarting the engine and unable to make the airpark, so he elected to land in a cattle pasture, short of the airpark. During the landing, the airplane nosed over. The pilot reported that he did not know why the engine stopped producing power. He stated that the fuel selector valve was in the “BOTH” position; the mixture control was set to rich; the throttle lever was in; and there was no adverse weather. He further stated that it was a fuel-injected engine and that he had no issues with it during the earlier portion of the flight. He also stated that the airplane had about 30 gallons of fuel. Postaccident examination of the airframe and engine revealed no evidence of mechanical damage to the engine. The engine could be rotated manually by the propeller, and rotational continuity was established throughout the engine and valve train to the accessory section. Engine timing was verified to be appropriate. The right magneto produced spark at all ignition leads. The left magneto was equipped with an electronic ignition system. The top spark plugs were removed and displayed normal wear signatures. Further, fuel system continuity was established from the main fuel tanks to the engine fuel injection nozzles. Additionally, the fuel was tested for water with negative results, and the fuel pump was operational. An external fuel tank was attached, and the engine was run at various power settings for about 10 minutes. A function check of the magnetos showed a decrease of about 50 rpm when operating on either the left or right magneto. When the throttle was advanced to the full forward position, the engine’s rpm was about 2,300. Overall, the examination revealed no evidence of any mechanical anomalies that would have precluded normal operation of the airplane.