FAA Powerplant Written Practice Test

How should carbon deposits be loosened when cleaning turbine engine fuel nozzles?

1. By using a hard metal tool

2. With steam cleaning

3. With an approved cleaning product

4. By soaking them in oil

The correct answer is: With an approved cleaning product

When cleaning turbine engine fuel nozzles, utilizing an approved cleaning product is the appropriate method for loosening carbon deposits. These cleaning products are specifically formulated to safely break down and dissolve carbon buildup without damaging the components of the fuel nozzles. Using approved cleaning products ensures that any chemicals used are compatible with the materials in the fuel nozzles and do not lead to adverse reactions or degradation of the nozzle structure. This method also promotes effective cleaning while maintaining safety standards and preserving the integrity of sensitive engine components. In contrast, employing a hard metal tool could risk scratching or damaging the surfaces of the nozzles, potentially leading to leaks or failure. Steam cleaning, while effective for some types of deposits, may not adequately address the specific type of carbon deposits found in fuel nozzles, and could introduce water into areas that require strict control of moisture. Soaking in oil is not effective for removing carbon deposits, as oil will not react with or dissolve the carbon, leaving the deposits intact.