What happened
Approximately 30 minutes into the flight, the right engine of the aircraft lost power. The pilot attempted to restart the engine but was unable to do so. In response, the pilot secured the right engine and feathered the propeller.
Shortly after the engine restart attempt, the pilot reported a complete loss of electrical power, which rendered the onboard radios inoperable. The pilot subsequently transitioned the landing gear lever to the down position and established an approach to runway 5R for an emergency landing. Upon touchdown, the airplane skidded off the left side of the runway.
The investigation
Investigators performed an extensive examination of the aircraft and engine assemblies, but the inspection failed to disclose any mechanical malfunctions or component failures. The electrical system was also functionally checked; no mechanical problems were identified during this process. When the master switch was turned to the on position, 75% of the battery power was restored to the airplane, and the electrical power source proved sufficient to activate the landing gear doors.
An examination of the fuel system traced fuel from the tank to the fuel control unit. The right fuel shut-off valve was found to be functioning normally with no mechanical issues discovered.