<b>Comparison of Different Liquids Used in Fuel System of an Aircraft</b> There have been several aircraft accidents, due to the water ice formation in the aviation fuel. It concern a computational study of the process of removing water from an aircraft fuel tank by pumping Nitrogen Enriched Air from the bottom of the tank. This is important procedure for smooth, efficient, and safe operation of the aircraft engine. Since the large transport airplanes fly at very high altitudes, where ambient temperature can reach 6 c, water may freeze can blockage in fuel tank. In order to reduce the water contamination in fuel tank by pumping NEA through fuel tank as a part of their inerting. finally, it conclude the amount of accumulated water is depend on the bubble size and rising speed velocity can be calculated. Aircraft, water contamination, fuel system, On Board Inert Gas Generation System, Nitrogen Enriched Air, Bubble 2232-2235 Issue-5 Volume-2 J. Nirmala | S. Indumathi