What happened
During an attempt to return to the airport following a loss of power in the left engine, the pilot experienced a subsequent loss of power in the right engine. While attempting a left turn to reach the airfield, the pilot did not follow established emergency shutdown procedures. This resulted in a significant left yaw, causing the aircraft type to drop on its left wing in a manner consistent with a stall.
After regaining some level of control, the pilot directed the aircraft toward a street. The aircraft struck the roof of a residence while in a right bank and subsequently cartwheeled across the roadway. No fatalities or injuries were reported in the source material.
Findings
Investigation of the left engine revealed severe damage caused by detonation. Additionally, the turbocharger wastegate door was missing its anti-vibration spring, and the pin connecting the door to the actuator had failed. Evidence suggested that this pin failure had occurred prior to the accident flight, as soot inside the left wastegate indicated the door had remained in a fully closed position for an extended period.
Regarding the right engine, no evidence of malfunction or failure was identified. The damage observed on the right propeller was consistent with the engine being under power at the moment of ground impact.