ETOPS Flight Planning
Question about ETOPS dispatching.
Maximun Diversion time (90, 120,..) is only used for determining area of operations, and therefore is not an operational limit for conducting a diversion which has to cope with the prevailing weather conditions (Airbus ETOPS Manual). An ETP is therefore obviously calculated in forcasted atmospheric conditions (logical).
So you determine your area of operations drawing circles using the, let’s say, 90min diversion distance (based on your 1LE speed) centred on each adequate airport.
You then calculated your optimized routing, based on forecasted atmospheric conditions, and make sure this route stays within the circles. You then make sure you have enough fuel for the most critical fuel scenario at CP(ETP). This seems obvious.
Now, what I don’t understand is that I’ve been told that I ALSO have to run my optimized routing OFP in still wind conditions. Your fuel required will of course be different (and could be more restrictive in still wind )… but why do you have to do that?
Any written requirement on this somewhere? I don’t find anything.
In Jetplan user manual:
“To determine if an optimal route meets the requirement of ETOPS, an ETOPS flight plan must be calculated using the optimal route under a “zero wind” condition.”
My opinion is that, if your optimized route stays within the circles (still winds) and you have enough fuel for most critical scenario at CP (forcasted winds), you meet the requirements.
I am probably wrong.