What happens if the loaded fuel is less than the block fuel?

The correct understanding hinges on the definitions and implications of loaded fuel versus block fuel. Block fuel refers to the total amount of fuel that is required for a flight, which includes the fuel necessary for takeoff, climb, cruise, descent, and reserve. When the loaded fuel is less than the block fuel, it means there is not enough fuel on board to safely complete the planned journey, including any contingencies such as deviations for weather or a need to hold.

If the flight is undertaken with insufficient fuel, it poses significant safety risks such as fuel exhaustion before reaching the destination, leading to potential emergencies. Regulations and operational standards require that the aircraft must not be dispatched with insufficient fuel for the flight. Therefore, if the loaded fuel does not meet or exceed the block fuel requirements, the flight cannot take off, ensuring the safety of the aircraft and its occupants.

This situation is serious enough to warrant grounding the flight until the necessary amount of fuel can be loaded. Hence, grounded flights due to insufficient fuel levels are not only about adherence to regulatory requirements but also about ensuring the safety of operations.