Which system helps maintain fuel quality in the APU?

The filtration system is essential for maintaining fuel quality in the APU. It works by removing contaminants, such as dirt, water, and other impurities, from the fuel before it enters the combustion chamber. These impurities can cause operational issues, damage to engine components, or reduced efficiency. A clean fuel supply is crucial for the reliable operation of the APU, ensuring that it can perform optimally and efficiently.

The cooling system primarily deals with regulating the temperature of the APU components to prevent overheating, while the electrical system controls power distribution and management, and the ignition system is responsible for initiating combustion. While these systems are vital to the overall function of the APU, they do not specifically address the quality of the fuel being used. Therefore, the filtration system is the key component dedicated to ensuring that fuel remains uncontaminated and safe for combustion.