Art From United Kingdom, joined Feb 2005, 3639 posts, RR: 1 Posted (8 years 9 months 2 weeks 6 days 2 hours ago) and read 3687 times:
It occurs to me that if an aircraft flies direct from Europe to Australia, it has to carry about twice as much fuel as it would if it stopped to refuel at half distance. For the first half of the direct flight, the aircraft will be carrying tens of tons of fuel more than if it was fuelled to stop halfway.
Even allowing for extra fuel used to descend and climb due to a technical stop, I wonder how much extra fuel is used flying direct (for the payload carried) compared with that used if a technical stop is made. My guess is that there is a dramatic increase. in fuel consumption per payload ton That seems a pretty irresponsible way for long distance aviation to operate. Should airlines (and manufacturers) therefore abandon the idea of ULR flights? Should governments put punitive taxes on such flights to discourage them?
ILOVEA340 From United States of America, joined Oct 1999, 2100 posts, RR: 4
Reply 1, posted (8 years 9 months 2 weeks 6 days 2 hours ago) and read 3673 times:
It's actually far less efficient to do a refueling stop. I know it was looked into for a couple of potential routes with my company and the fuel burn of takeoff and climb far outweighs any gains from having a lighter aircraft.
Roughly 15% more, using the same (heavy) ULR aircraft, or 20% more if you account for the fact that the one-stop flight can be flown at the same payload with a lighter non-ULR aircraft.
Quoting ILOVEA340 (Reply 1): It's actually far less efficient to do a refueling stop. I know it was looked into for a couple of potential routes with my company and the fuel burn of takeoff and climb far outweighs any gains from having a lighter aircraft.
Since it is unlikely that 15% of the fuel load is used for takeoff and climb, I highly doubt this assertion.
Quoting WorldTraveler (Reply 3): if the thesis was true, airlines would be constantly cutting routes "in half" in search of the supposedly lower fuel burn. obviously, the thesis is not correct.
Dubai is (and increasingly will be) a great example.