If the first fuel sample is contaminated, what is the next step?

When the first fuel sample is found to be contaminated, it is important to ensure the safety and integrity of the aircraft's fuel system. Draining a specific amount, often one gallon, and taking another sample is the appropriate follow-up action. This step allows for further assessment of the fuel quality without introducing unnecessary risks to the aircraft's operation. The new sample can help determine if the contamination is local to the initial sample or if it is present throughout the fuel system.

Taking another sample after draining helps to confirm the quality of the fuel that will be used in flight. If the new sample is clear, it indicates that the contamination may have been isolated and not indicative of the entire fuel supply. This action also follows standard procedures for handling fuel contamination situations, prioritizing safety and operational readiness.

Other options, such as notifying the aircrew or performing a complete system inspection, are important procedures but would typically come after verifying and ensuring the fuel quality through sampling. These measures are essential in a broader context, but in the immediate situation following a contaminated test, the focus must be on gathering more data concerning the fuel condition.