Minimum safe fuel
There is widespread confusion amongst slf between minimum safe fuel and minimum fuel. Absolute minimum fuel is a legal amount that cannot ever be reduced before departure. Within the same regulations there is reference to other conditions that may require more than the absolute minimum. Like very bad weather or very busy airports. Not so obvious to the casual observer will be fuel calculations that allow for additional fuel burn for engine failure at a critical point of the flight etc.
When all of the operator approved fuel load and all the little extras that are present but not detailed in the regs, are carried, you have the minimum fuel actually intended by regulation. The actual quantity of some of the extras is determined by the captain. If the regulation extras are actually needed in a particular case, but not carried the captain is not complying with regulations.
If the crew, during flight, negligently allows or causes the fuel to not include the known required extras, the flight is not technically compliant, and safety is degraded. If the minimum extras have been expertly considered and the crew conserve that fuel while it is still required, the aircraft commenced with minimum fuel. If conditions require extras, they are not optional.
So really, there is no minimum safe fuel, just minimum fuel. If an operator successfully induces captains to take less than their fully assessed minimum fuel, or the captain's expert assessment is deficient, the flight is not legal, and the operator and/or the pilot are unsafe.
In this context, extra fuel does not mean more than is needed to be legal. It means the additional required fuel above the absolute minimum that some pilots are pressured to accept.
If the assessed minimum fuel cannot be carried due to the aircraft payload, another solution need to be considered. In-flight re-planning, a fuel stop enroute or reduce payload for sufficient fuel. In-flight re-planning might already be in the flight plan, or be of limited assistance. Not many operators will go for fuel stop and unsafe airlines will avoid off loading.
Finally the captain may have decide if he is the captain.
Last edited by autoflight; 23rd August 2013 at 07:26.