Incident Overview
A cargo aircraft, while being positioned to begin a revenue cargo flight, experienced an electrical failure during the approach. As the aircraft turned final and the landing gear handle was placed in the down position, the pilot-in-command (PIC) noted the dimming of all lights and a complete loss of communications. The PIC was unaware that the landing gear remained retracted until the propeller tips contacted the runway surface.
Sequence of Events
During the landing slide, the left inboard fuel tank drain was sheared away, allowing fuel to leak from the tank. The leaked fuel subsequently ignited. The PIC reported that he elected to land rather than execute a go-around because the aircraft was in a Terminal Control Area (TCA) with no communications and no lights.
Investigation Findings
Post-accident investigation failed to reveal any electrical malfunction. The operator stated that it was normal practice to start the engines with the alternators off. The circumstances of the accident were consistent with a loss of alternators and battery-only operation. The alternators were tested and found to be functioning properly after the accident.