Which procedure must be followed when sampling fuel from an aircraft?

Wearing personal protective equipment (PPE) when sampling fuel from an aircraft is essential for ensuring the safety of the personnel involved. Fuel can be hazardous, containing various toxic and flammable substances that pose risks to health and safety. PPE, which may include gloves, goggles, and other protective attire, acts as a barrier against potential spills or splashes that could occur during the sampling process.

In addition to personal safety, PPE helps to minimize the risk of contamination of the fuel sample itself. Properly protected personnel are more likely to conduct the sampling process correctly and securely, thereby ensuring the integrity of the samples being collected for analysis.

The other options do not align with best practices for fuel sampling. For example, taking samples from high drain points may not always provide a representative sample of the fuel's quality. Recommendations regarding time periods for sampling may also vary based on the specific procedures in place, but those would not inherently enhance safety in the same way that PPE does.