Agricultural aircraft loses power due to supercharger failure (N9874)

What happened

The pilot reported that during an agricultural application flight, the engine suddenly lost power as he was preparing to execute his first swath run. As the aircraft began to lose altitude and thrust, it descended to approximately telephone pole height before stalling. The pilot was unable to recover control, and the aircraft collided with the terrain at a steep angle.

The investigation

A post-accident examination of the engine revealed that the supercharger shaft had sheared. This mechanical failure directly resulted in the loss of power during the critical phase of flight. Reports indicated that the aircraft was fully loaded with both fuel and dry fertilizer at the time of the incident.

Findings

The primary factor contributing to the accident was the mechanical failure of the supercharger system. The shearing of the shaft caused an immediate and unrecoverable loss of engine power while the aircraft was low to the ground and heavily loaded.