but the A359 has the advantage in the induced drag and the engine's TSFC in a way that it would close the gap a bit
Also has the advantage of higher cruise altitudes with the thinner air which reduces drag and fuel flow.
I am curious though, how did you calculate the 10% difference?
Seems to be as scientific as pitting ones finger in the mouth, removing it, holding it up, and then professing the wind strength, direction, temperature, and pressure.
I gave the SQ22 a reserve fuel of 4.5t to match that of QF9's flight. I counted the remaining fuel as payload as it was optionally carried.
The FCOM numbers indicated that the 787-9 with 21 tonnes of payload (including catering) when landing with 10.1 tonnes of reserve would burn 93.225 tonnes, when landing with 4.5 tonnes 90.379 tonnes. That equates to a cost of 508 kg/tonne to carry a tonne.Then you would need to take the 5.6+2.846=8.446 tonnes out of the 21 tonne payload as they are at MTOW limited. The 787-9 would be down to 12.554 tonnes of payload (about 125 passengers), and we haven't even taken account for catering.
You can ignore the typical OEW on wikipedia, yet use the correct OEW for the 787.
Official numbers on wiki, now I have heard everything
Now I know where Lion Air went wrong, they used Boeing data instead of wiki.
No the A350 number on wiki is not the BEW/OEW which is more like 135 tonnes for a standard A350, that number would be an BEW/OEW+catering number which is called Dry Operating Weight. It seems to be very heavy, even for our longest flights we only take 4-5 tonnes of catering. 7 tonnes of catering is excessive. That number would not be representative of the SQ ULR aircraft. We also know the ULR is several tonnes lighter than the standard A350 with half of the water tanks, cargo system removed from the forward bay, it has the better engines, the new winglets, and other -1000 enhancements.
payload = 249 - 128.5 - (91+4.5) = 25t
I have posted before on this thread "Working backwards from your ZFW (153.8) minus the payload (210 pax approx 21 tonnes) gives a DOW of 132.8 tonnes, I was working on an OEW of 128.85 for the 787-9, that would allow about 4 tonnes for catering."
We never use OEW in real life, we have the basic weight, add catering, and get D(ry)OW. The reason being the catering for a 787-9 domestic sector say BNE-MEL would have two pilots is going to be vastly different to an international flight like PER-LHR with 4 pilots and extra cabin crew.
They cannot have 25 tonnes of payload, as it leaves no weight for catering and the heavy crew for the long haul flight etc.
The 787-9 does not have the range to fly 25 tonnes of payload plus catering over 8000 nm, let alone 8200 nm. This the total payload in steps of 5 tonnes from 0 to 40 tonnes, over 5000-8000 nm. The 5 tonne payload capability would be an empy aircraft with just catering loaded.
For SQ 22
Payload = 273 - 142 - (101 +4.5) = 25.5t
WHERE does it say SQ22 burnt 101 tonnes ? Where does it say they had 4.5 tonnes reserve ?
As I mentioned to you before you cannot know the amount of fuel burnt until the flight has been completed. You are happy to accept the amount of fuel burnt for the 787, but you want to compare that to the planned required fuel before departure (the twitter picture were pre departure). They also said they had in excess of 10 tonnes above that number available at the destination, not 4.5.
So the A350 flew 2% further with 2% more payload. The 787-9 had 9.5% less fuel burn per hour.
Another F in maths and comprehension there. The A350 had a payload of around 23 tonnes for that flight plus it landed with over 10 tonnes at the other end. so 23 tonnes plus the extra fuel they landed with that could be converted to payload (10.1-4.5)= 5.6 = 28.6 tonnes. 28.6/21.0 = the A350 carried 36% more payload. The A350 also had the capability to increase TOW another 7 tonnes, where the 787-9 was a half tonne below MTOW, which would be around another 5 tonnes in payload for the A350 (ballpark 2 tonnes to carry the extra 5 tonnes), which would mean 60% more payload over a longer flight time.
That just reduced the 787-9's fuel burn advantage from 9.5% to 6.5%. How can anyone accept Zeke's graph that shows less than 1% difference?
Easy because the FCOM data was for the same payload, over the same distance, in ISA conditions. The A350 here is lifting at least 36% more than the 787-9, it is flying longer and it is ISA+14 which I have already described above adds over 4 tonnes of fuel.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News