Incident Overview
During climb at 6,300 feet, the pilot reported a complete loss of power on the right engine. Approximately four minutes later, after initiating an emergency descent for a landing, the pilot reported that the left engine had also lost power. The aircraft subsequently impacted a driveway and skidded into a building.
Right Engine Failure
Examination revealed that the right engine failed due to shifting of the engine case halves. Review of engine maintenance records indicated that several cylinders had been replaced in recent months. The cylinder through bolts, which are used to torque the engine case, were found to have been improperly torqued by maintenance personnel.
Left Engine Failure
A reason for the loss of power on the left engine was not determined. The investigation was unable to identify a specific cause for the left engine failure.
Probable Cause
The official probable cause was determined as the loss of power on the left engine for undetermined reasons. A contributing factor was the failure of the right engine due to maintenance personnel's failure to properly torque the cylinder through bolts.