What minimum markings are required on fuel filler covers of utility category aircraft?

The correct answer focuses on the specific requirements for marking fuel filler covers on utility category aircraft. Those aircraft that utilize aviation gasoline (Avgas) must have specific markings to avoid misfuelling and ensure safety. The requirement for marking with the word 'Avgas' and indicating the minimum fuel grade is particularly crucial in preventing the use of incorrect fuel types that could lead to engine damage or failure.

By clearly designating 'Avgas' along with the minimum fuel grade, ground crew and pilots can readily identify the appropriate fuel type required for the aircraft, thus minimizing the risk of errors during servicing. This emphasizes the importance of clear communication and proper identification of fuel requirements in aviation operations, catering specifically to utility category aircraft that generally utilize Avgas.