What should the appearance of a fuel sample be?

The appearance of a fuel sample is crucial for ensuring that the fuel is clean and free from contaminants. A fuel sample that is clear and bright indicates that it is of good quality and suitable for use in aviation operations. Clarity signifies that there are no suspended particles or water present in the fuel, while brightness suggests that there are no contaminants affecting its quality, allowing for optimal engine performance and safety.

A cloudy appearance would indicate that there are possible contaminants, emulsified water, or other particulate matter in the fuel, which could lead to engine problems. Similarly, a dark sample could suggest the presence of degradation products or particulate contamination, which is not ideal for aviation fuels. An opaque sample would also imply contamination, which is not acceptable for safe operation.

Thus, the clear and bright appearance of a fuel sample is the standard expected for ensuring that it meets safety and operational requirements.