Summary
A helicopter experienced a flameout and ditched in the ocean. After being towed ashore on its floats, the fuel system was examined and found to contain at least 4 gallons of fuel. According to the helicopter manual, all fuel was usable except for about 1 gallon, ruling out fuel exhaustion as a cause. Further examination revealed foreign matter in the helicopter's fuel system. Similar foreign matter was found in the fuel truck that refueled the helicopter and in the fuel tank storage farm where the truck obtained its fuel. Laboratory analysis confirmed that fuel samples from the helicopter and the refueling source were chemically identical.
Investigation Details
Examination of the helicopter's fuel system disclosed the presence of foreign material. Investigators then inspected the fuel truck used to refuel the helicopter and the storage farm tank that supplied the truck. Both sources contained foreign matter of similar appearance. Chemical analysis of fuel samples from the helicopter and the refueling sources showed they were chemically the same. The helicopter manual indicated that all fuel was usable except about 1 gallon, so fuel exhaustion was not a factor.
Findings
The helicopter ditched in the ocean following a flameout. The fuel system contained foreign matter, and the same type of contamination was found upstream in the fuel supply chain. No probable cause has been stated in the investigation source.