Water in aviation fuel can cause the engine to either sputter or completely fail. The gascolator—also referred to as the fuel main line strainer, sediment bowl or fuel strainer—acts primarily as a fuel drain for water and small particles of sediment. The gascolator is found at the lowest point of the aircraft’s fuel system, usually located below the level of the aircraft’s carburetor and fuel tanks in helicopters.
A water/alcohol-indicating paste test conducted by the NTSB revealed that there was water present in the helicopter’s fuel.
Read more: http://suindependent.com/final-findings-helicopter-crash-venuti/