Private Pilot Private Practice Exam

Filing the fuel tanks after the last flight of the day is beneficial primarily to prevent moisture condensation by minimizing the airspace in the tanks. When fuel tanks contain air, temperature changes can cause condensation to form inside the tank, leading to water accumulation. Water is detrimental to engine operation, as it can cause corrosion, decrease fuel quality, and potentially lead to engine failure. By filling the tanks to the top, you eliminate the airspace, thus reducing the potential for condensation and effectively protecting the fuel system from moisture-related issues. Additionally, keeping the tanks full also helps in managing the overall health of the aircraft, as it reduces the risk of fuel contamination and helps ensure a stable fuel supply for the next flight.