Ultra Long Haul fuel efficiency
 

Just reading a bit about this Project Sunrise. I saw this comment from the Lonely Planet founder on Linked In , which surprised me ! Usually the RAS puts out respectable information. Is the quoted 30% extra fuel burn fair dinkum or just juggling of figures ?

”I'd been wondering what that extra cost might be until January this year, when a gathering at the Royal Aeronautical Society in London revealed figures that showed it takes 30 per cent more fuel to operate using Perth as the one stop from Australia's east coast to London (QF9), rather than having a more evenly spaced stop – Singapore or Dubai, for example.

Any comments?

I think this has already been beaten to death someone on the Australia thread - search for "fuel"

Yep - fuel roughly 37% of costs on these ULH flights and crew about 11%. Half of that being FAs and another good chunk being accommodation. Pilots being a tiny tiny tiny fraction of the overall costs. Fuel goes up and the whole experiment is over.

Yes, those engines are pushing their limits in order to move half a tank fuel half way across the planet in order to fly the other half without a pit stop.

On a 15hr sector with new generation jets you are looking at about 300kg of extra burn for every extra tonne of fuel carried. Can only imagine what burn old generation jets had on a comparable sector

Turning final, I think you'll find the figure closer to 600kg additional burn per ton for that sector length.

For some perspective, the QF 9 when it flies Melbourne to Perth, which is about a 3 and a half hour flight, will burn roughly an extra 100kg of fuel per 1000kg of extra weight (fuel/bags/passengers/freight). On the 18 hour leg from Perth to London it will burn an extra 600kg of fuel per 1000kg of weight. With a fuel load of about 100,000kg you can see how carrying the extra fuel to fly so far means you burn an awful lot of it just to carry the weight of the fuel. So clearly a stop half way would, from purely a fuel burn perspective, be a more efficient journey.

If my memory serves me correctly the old rule of thumb when I joined QF on the B747 classic and before this info was provided on the flight plans, was the aircraft would burn the additional fuel (added over and above the flight plan TOW) over a 27 hour flight/period.
For example with a flight time of 9 hours, if you added an additional 3000kg the extra burn would be 1000kg, leaving you with only 2000kg additional at destination. On a 3hr flight an additional 1800kg would have an extra burn of 200kg leaving only 1600kg of the extra 1800kg at the other end.
Based on numbers given by the previous posters it may still appear to be reasonably accurate with the newer aircraft.

Cant comment on other types but for the 350-900 on a 15.5hr sector looking at roughly 360kg per 1T. Obviously pushing that to 17/18 sector length would jump those numbers up quite a bit id say

Anyone from SQ here.......

A350-900 7320nm sector, near enough to nil average wind, flight time 15 hours 20, taking off at max TO weight 277.0 carrying 37 tonne of payload took 103 tonne of fuel and burnt 94 of it. If you took a tonne of payload off, your fuel burn would have reduced by 373 kg. If your RTOW was restricted by a tonne the ratio of fuel/load to come off would be 271kg/729kg.
I hope you guys get some input to your mattress selection, cause I’d love to kick the prick who choose ours fair in the nuts.

The companies attitude to crew rest is you take what the manufacturer supplies.

On an A380 MEL-LAX with a 13:30 flight time the burn will be between 400 and 500 kg/tonne of extra fuel or payload. It's 484 today at 14T under MTOW.