What happened
The pilot was operating an aircraft on a flight when it became necessary to return to the departure airport for landing. During this phase of the operation, the engine lost power unexpectedly. Unable to maintain altitude or continue the approach with normal power settings, the pilot initiated a forced landing procedure. The aircraft impacted a corn field near the airport. The impact resulted in significant damage to the airframe.
The investigation
Following the accident, investigators examined the aircraft and its systems to determine the cause of the power loss. A detailed inspection of the engine revealed excessive carbon deposits within the exhaust stack. Additionally, the examination found that the primer valve was not fully closed. Analysis indicated that the engine was running with an excessively rich fuel mixture due to the primer being in this open position.
Findings
The investigation determined that the primary factor leading to the accident was the improper setting of the primer. The failure to fully close the primer caused the engine to run too rich, leading to a loss of power. This mechanical condition prevented the pilot from completing the landing safely. The excessive carbon in the exhaust stack was also noted as a contributing factor to the engine's performance degradation.
Safety message
Pilots must ensure that all engine controls, particularly the primer, are fully closed after starting unless specifically required for operation. Improperly secured components can lead to dangerous fuel mixture issues and sudden power loss.