Incident Summary
A pilot was flying a positioning flight when the right engine surged and experienced a partial loss of power. The pilot adjusted the power and fuel mixture controls, but seconds later the engine surged again. Noting that the fuel flow gauge indicated below 90 pounds, the pilot activated the right fuel pump. Subsequently, the left engine also surged, and the pilot performed the same corrective actions. Suspecting fuel starvation, the pilot diverted to an alternate airport. Shortly thereafter, both engines lost total power, and the airplane impacted trees and terrain approximately 1.5 miles from the destination.
During the post-accident examination, the left fuel tank was found breached, but no fuel leak was apparent. Investigators recovered about one gallon of fuel from the wreckage.
Fuel Quantity Investigation
Before the flight, the company's route coordinator stated that the pilot checked the fuel gauge and reported 120 gallons on board. However, a review of the airplane's flight history revealed that after the previous flight, the airplane had been left with approximately 50 gallons of fuel, and there was no record of refueling between that flight and the accident flight.
Another company pilot noted a unique characteristic of the airplane's fuel gauge: after the electrical power was turned off, the gauge would rise 40 to 60 gallons before eventually returning to zero. In an examination of a similar aircraft operated by the same company, when the master switch was set to the battery position, the fuel gauge indicated about 100 gallons. When the switch was turned off, the gauge reading rose to 120 gallons and then dropped off scale below empty. Additionally, while fuel was visible in the tank after removing the fuel cap, there was no reliable method to visually confirm the exact quantity.
Probable Cause
The total loss of engine power due to fuel exhaustion and the pilot’s inadequate preflight inspection, which did not correctly identify the airplane’s fuel quantity before departure.