Down under
Think about a few more variables...
- 23.6 tonne payload or less, long range cruise, drift climb, lots of places to recalculate variable reserve and enroute alternate min holding fuel on arrival, not in the morning fog risk etc etc. etc.
Then have a look at the published payload range graph and see what's included. vis variable fuel reserve, mandatory alternate
no etops additional fuel requirement and lots of places to go on the way if a bit short on gas for this trip. Spare crew in LHR for a recovery if have to plonk into FRA/CDG/ATH/FCO etc due lovely LHR weather.
Not a problem most of the time