Thank's Long Haul for the reply. It is an interesting solution.
How is it written in your Sops?
In order to "add additional fuel" as you wrote, it looks like you're checking before departure with the Flaps 20 inflight tables to make sure you can dispatch...
Checking dispatch requirements with inflight tables due to the lack of dispatch tables for the specific configuration, isn't there something a little unnatural?
If this Flaps 20 question was not of concern at dispatch you obviously would not have to check the flaps 20 inflight tables and possibly "add additional fuel"?
It looks like your airline is trying to mitigate.
However, I understand that if you don't exceed the LDA with the Flaps 20 inflight tables then you're not adding fuel, is that correct? Which means it is then acceptable and obviously planned to land Flaps 20 at the alternate airport even though the Flaps 20 landing distance you checked is only satisfying the LDA and not the RLD (0.6, 1.15 factors)?
It comes down to knowing you'll land Flaps 20 and not checking the RLD but only the LDA. What if 1.667 x (uncertified) Flaps 20 landing distance exceeds the LDA?
It may have the blessing of the regulators but it may also be a loophole... Which is what I'm trying to figure out since we don't do anything (European legacy as well) and also have the same blessing... It is then a variable-geometry blessing!
Not to mention that for a short trip like US east coast to western Europe, you'll have a 3% contingency fuel of less than 1 ton and a final reserve fuel of about 2.6 tons on a B772. Occurring or not after dispatch, the use of contingency fuel is here irrelevant since you'll end up anyway with less than 4 tons at the alternate even if you don't use that contingency fuel...
Do you mind asking one of these guys, just to check that there is a deliberate blessing?