What happened
During the third segment of a flight, the pilot observed a fuel crossfeed light illumination. After attempting to reset the indicator, the pilot decided to divert to a nearby airport to investigate the issue. During the approach, the right engine lost power, causing the autofeater system to feather the propeller. As the pilot entered the traffic pattern, the landing gear was extended, at which point an electrical system failure occurred. Following this, the left engine stopped responding to power lever inputs.
While on the base leg of the approach, the aircraft was positioned below the necessary flightpath. Despite the pilot's attempt to maintain control, the aircraft struck an embankment on airport property. The impact caused substantial damage to the fuselage and both wings.
Findings
Post-accident inspections of the airframe and engines showed no mechanical abnormalities that would have prevented standard operation. Evidence from the propeller signatures suggested the right engine was producing little to no power, while the left engine was likely producing some power at the moment of impact. The reason for the initial loss of power in the right engine remains undetermined.
Regarding the electrical failure, the master switch was found in the OFF position. Because the aircraft had been flying for approximately 30 minutes, it is believed the plane was running on battery power, likely because the pilot failed to activate or accidentally deactivated the generator switches. This would explain why the electrical system failed after the landing gear extension, as the battery would have been exhausted. The cause of the left engine's failure to respond to throttle inputs could not be established.