@Zlin77 Thank's for the reply!
Aeroplane is not only deemed serviceable on departure, it is serviceable! Otherwise it would not depart...
But being "serviceable" does mean it will operate normally and will therefore trigger a non normal C/L calling for F20 whenever it will reach less than 4 tons of fuel on board, as should any serviceable B777.
Reaching this quantity at the alternate is a perfectly normal situation complying with fuel policy regulations for a "serviceable" airplane departing with the minimum required fuel.
Whatever happens after take off is indeed a matter of in-flight management and I thought I made clear this was not the question, emphasising that the crew could deal with the fuel as he sees fit.
But at planning stage, since you can only consider using the taxi fuel during taxi, the trip fuel for the trip and the alternate fuel to divert to the alternate, what quantity of fuel is then supposed to remain on board when reaching the alternate? The answer is simple : the final reserve fuel and possibly the contingency fuel, for a total of possibly less than 4 tons. This is how a "deemed serviceable" airplane can only be considered having to land F20 and this being already known at planning stage. Thus the logical question that Long Haul perfectly summarised : "one should be dispatched according to the dispatch requirements" when planning to arrive at the alternate in a F20 situation.
Why planning a F30 landing at planning stage if you know you should land F20 (unless discarding the NNC) due to the fuel quantity you're choosing at planning stage?
I sincerely wish the answer could be as simple as having a serviceable airplane thus planning F30, but I doubt it. Otherwise, what would be the reason for this Legacy to add additional fuel at planning stage to prevent landing F20 in some situations?
Departing with minimum fuel only leaves one option to avoid landing at the alternate with more than 4 tons : not using the contingency fuel and deciding an early diversion without performing the approach at destination in order to use less trip fuel and less alternate fuel. I'm pretty sure you'll agree this is not the normal planning stage fuel policy, although it is definitely what could "happen after takeoff". What WILL "happen after takeoff" is having to deal with LDA and not anymore with RLD.
This is all why my question is about RLD at planning stage. Why is it that you have to take in consideration all expected factors (MEL, CDL, TAF, even a possibly wet or contaminated runway condition, etc.) BUT NOT the fact that the fuel quantity you have on board WILL have you land F20 if you don't take more fuel (or if you disregard the NNC)? Why neglecting only that expected factor which is the normal consequence of landing with less than 4 tons when departing with a fuel quantity that is supposed to have you land with less than 4 tons when simply following the flight plan?
I hardly think it is a matter of being deemed serviceable. But I don't have a monopoly on the truth, I'm looking for it as everyone is, thus my question...
It might comply with regulations, but why?
And how can it be in compliance since the regulations say "Due account shall be taken of aeroplane configuration, environmental conditions and the operation of systems that have an adverse effect on performance."?
Isn't it an aeroplane configuration? Isn't operation of systems including performing the NNC? isn't landing F20 having an adverse effect on performance compared to a F30 landing?
I'm only looking for an explanation.
@Long Haul, thank you very much for taking the time to explain in detail your process. This is a clever option since no one has the F20 landing dispatch tables. Thus my question, trying to figure out what other operators are doing, from nothing (as we do) to something more clever. I take good note of this idea because compliance with regulations is the airline obligation (as it is also the commander's IMHO...) and that is part of why I ask the question... Hopefully I don't and won't lose any sleep over it, thank's for the wise advice. May I furthermore ask what is the ZFW amount? And are you operating both the B772 and the B773?
Last edited by Diogene; 11th Aug 2017 at 09:53.