Where is ice formation likely to occur in a turbine engine fuel system?

Ice formation in a turbine engine fuel system is most likely to occur at the fuel filter. This is primarily because fuel filters can become saturated with moisture, especially when fuel is cooled during flight or when temperatures drop significantly.

As fuel passes through the filter, any water present can freeze and obstruct the flow of fuel. This blockage can lead to reduced fuel flow to the engine, resulting in potential performance issues or failure. Unlike the fuel tank or fuel lines, which may have a larger volume of fuel maintaining a certain temperature, the filter has a smaller volume where localized cooling occurs, thus making it more susceptible to icing.

Furthermore, while ice formation could theoretically occur in the fuel tank or fuel lines, the conditions needed for significant ice blockage are most frequently realized at the filter. The fuel pump generally operates with a constant flow and is heated by engine components, making it less prone to ice accumulation.

Thus, the fuel filter represents the critical point in the fuel system where ice can accumulate and impact engine operation, affirming the selection as the correct answer.