Have several screenshots ETOPS fuel is being added to flight plan when not needed and once added the enroute burn is not being updated for the increased takeoff weight caused by the added ETOPS fuel.
Hi,
Regarding ETOPS fuel being boarded when not required, none of the extra fuel and only a portion of the contingency fuel are considered to be available when evaluating the critical fuel scenario. Given the following example you provided:
The critical point is at the ETOPS exit. Here we can see that the required CFUEL is 21.5, and we plan to have 28.8 on board.
When checking if we will have enough fuel to divert, we ignore any extra/wxx/atc/etc fuel because there is no requirement for this fuel to still be in the tanks at this point (it could be used by the pilots during departure, or at any other point prior to this). Removing the extra fuel brings our available fuel at the critical point down to 26.6 (28.8 - 1.5 extra - 0.7 atc = 26.6).
In addition, only a portion of the contingency fuel can be considered to be available at the critical point, equal to the percentage of the route flown. Since the critical point in this case is located roughly 91% of the way to your destination, we reduce the contingency fuel by 91% here. 91% of 5,521 kg is 5,024 kg, which means the actual planned FOB available for diversion becomes roughly 21.5 (26.6 - 5.1), plus or minus 0.1 due to rounding errors since the figures in the OFP are in thousands of kilos. We are right at the minimum, so the ETOPS fuel was indeed required in this case.
Regarding the ETOPS fuel not being considered in the burn, I will investigate further and try to improve this. But it’s a bit complicated to implement, might be a while.
Best regards,