Which of the following personnel is NOT authorized to inspect fuel samples?

The supervising mechanic is not authorized to inspect fuel samples. This distinction is important because the authority to conduct such inspections is typically reserved for personnel who have received specialized training and have the necessary qualifications to ensure safety and compliance with regulations. Qualified aircrew, shift supervisors, and Quality Assurance Representatives (QAR/QA) are trained to recognize the critical aspects of fuel contamination and to execute the proper procedures for sampling and analyzing fuel. By limiting the inspection of fuel samples to designated and trained personnel, the integrity of the fuel and the safety of the aircraft are maintained, as incorrect sampling or analysis could lead to serious operational hazards.