Incident Overview
During final approach, the pilot reported a fuel crossfeed 'warning' light. He attempted to troubleshoot the fuel system by cycling the right boost pump switch and resetting the auto crossfeed. The crossfeed light illuminated again, followed by the right fuel pressure light, and the right engine experienced a power loss. After feathering the right engine, the left engine also lost power.
Pilot Actions
The pilot cleaned up the aircraft and ditched in a lake short of the airport.
Investigation Findings
Post-accident inspection revealed that the left wing fuel tanks were empty, and the left nacelle tank had collapsed. The right wing fuel tanks were empty, but the right nacelle tank contained 19 gallons of fuel. Functional checks of the fuel supply, transfer, and crossfeed systems confirmed they were operable. All cockpit fuel system lights indicated normal system operation during testing.
Probable Cause
The probable cause was the pilot's not understanding the fuel system, and his subsequent inadvertent discontinuance of fuel to both engines.