What happened
The pilot was operating an aircraft during the return phase of an aerial application flight when the engine suddenly lost power. With no option to continue the flight normally, the pilot executed a forced landing in a nearby pasture characterized by rough terrain and uneven surfaces. The impact with the ground resulted in substantial structural damage to the airframe.
The investigation
Following the accident, mechanics performed a detailed disassembly of the engine to determine the root cause of the power loss. The inspection revealed a catastrophic internal failure within the engine block. Specifically, the connecting rod associated with cylinder number 8 had separated across its I-beam section. This broken component then flailed violently against adjacent parts inside the engine interior, causing widespread mechanical destruction that led to the immediate cessation of engine function.
Findings
The primary factor in this incident was the internal mechanical failure of the engine. The separation of the number 8 connecting rod prevented the engine from generating power, leaving the pilot with no choice but to land outside of a controlled environment. The rough surface of the pasture exacerbated the damage sustained during the landing.
Safety message
Regular and thorough inspection of engine components is critical for aerial application operations, which place high stress on airframes and powerplants. Early detection of internal wear or fatigue in connecting rods can prevent in-flight power loss and subsequent forced landings in unprepared areas.