What happened
Following a firm touchdown on the runway, the aircraft began to waver before veering toward the left side of the runway. The pilot attempted to correct the deviation by applying maximum right rudder, but the aircraft subsequently departed the right side of the runway. During the excursion, the aircraft yawed to the right and skidded along the surface. A witness observed the right engine power increasing to nearly full power as the aircraft moved toward the right edge of the runway. The aircraft then spun toward the left, eventually coming to a stop facing the opposite direction of its original landing approach. During the event, the propellers were observed making contact with the ground.
Findings
Post-accident inspections of the aircraft revealed that the left propeller assembly had been feathered, while the right propeller blades were bent forward. This damage pattern indicated that the right engine struck the terrain while operating at high power. Although the pilot initially attributed the loss of control to a malfunction in the main landing gear, investigations found that both throttle levers were in the closed position and both propeller control levers were in the full-forward position. The propeller control levers were noted to have very low friction, allowing them to be moved with minimal finger pressure. The evidence suggests that the pilot inadvertently feathered the left propeller assembly during the sequence of events. There were no reported engine or propeller malfunctions prior to the accident that would have prevented standard operation.