What does the term 'minimum fuel' indicate?

The term 'minimum fuel' refers specifically to a situation where an aircraft is low on fuel but has enough to reach the intended destination without issues. It serves as an advisory to air traffic control that the flight can accept no undue delays during its journey. This alert aims to ensure that air traffic management grants the aircraft the necessary priority to proceed to its destination efficiently, thereby avoiding any potential emergencies related to fuel starvation.

In contrast, the other definitions do not fully encapsulate the essence of what 'minimum fuel' signifies. While immediate diversion is a serious situation, 'minimum fuel' pertains more to the ability to complete the flight rather than requiring urgent changes to the flight plan. Similarly, while priority landing could be a consideration in critical situations, 'minimum fuel' does not automatically imply that priority landing is required. The term does not generally indicate unsustainability of the flight, as it simply means that care must be taken to avoid delays rather than signaling that the flight cannot continue at all. Thus, the correct interpretation aligns with the advisory nature of the term, underscoring the importance of maintaining clear communication between pilots and air traffic control regarding available fuel levels.