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It's claimed the plane will use 20% less fuel than the Airbus A350-900 while carrying a similar number of passengers -- the Flying-V will seat 314, while the Airbus A350 seats between 300 and 350. The design also mirrors the A350's 65-meter (213 feet) wingspan, enabling it to use existing airport infrastructure.

Source: CNN

All the efficiencies in recent years have come from better & better engines, huge high-bypass turbofans. This fuselage looks like it'd be a lot draggier than existing fuselage/wing structures since there is so much more frontal area.

If you have a window seat, that window cover better be open if I'm in that row!

enter image description here

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    $\begingroup$ Your observation is valid, see: Why are there no blended-wing passenger airplanes in operation? $\endgroup$
    – user14897
    Jun 3, 2019 at 15:33
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    $\begingroup$ Cargo doesn't have many of the issues passengers do, and we still don't see BWB specific for that. $\endgroup$
    – MikeY
    Jun 3, 2019 at 17:31
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    $\begingroup$ Flying-V is an investment scam. $\endgroup$
    – Robert Werner
    Jun 3, 2019 at 23:38
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    $\begingroup$ As I understand it, the flying wing lends itself to more efficient loading and cargo volume. A normal airplane can only carry fuel in the wings and volume maxes out if you are carrying potatoes chips. A blended wing offers a choice of cargo volume or weight! $\endgroup$
    – jwzumwalt
    Jun 4, 2019 at 1:45
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    $\begingroup$ There are fuselage tanks also. $\endgroup$
    – CrossRoads
    Jun 4, 2019 at 3:02

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I always ask myself the same question when I read such claims. Only that I am concerned about the huge wetted surface - frontal area is less of a problem here.

When I get hold of such studies, they invariably use projected future technology and compare that with current standards. As you correctly observe, most progress in fuel consumption over the last half century has been due to better engines with higher bypass ratios. Improved aerodynamics contributed maybe 30%, helped by higher aspect ratios and better surface quality made possible by using composite structures.

Another trick: BWBs (Blended Wing Bodies) with their wide fuselage are assumed to need less time for embarking and disembarking of the self-loading cargo. That will make them more productive but the complication of emergency egress from this wide fuselage (remember - all on only one side, within less than 90 seconds!) are waved aside. Also, structural penalties for a flat pressure vessel are assumed to be ridiculously low, so the BWB is even claimed to be more efficient structurally. Which it is, if you look at the spar weight alone. But skin surface area has weight, too - but not in those studies.

What also helps is to fly more slowly. That improves engine efficiency especially with high bypass ratio engines and allows thicker airfoils which certainly are needed in order to spread passengers over more than half of the wingspan. What is saved on the ground is then used up in the air, and the result is indeed a more efficient operation. If we were not bound by that magic number of Mach 0.85, new designs could indeed be more efficient still.

Remember that the A380 also was claimed to be 20% more fuel efficient? After being overweight (no wonder if scaling laws are observed, something the base of this claim conveniently forgot) what is left of that claim today? In reality, the competition uses the same technological progress and the comparison has to be made on a level playing field, with real data. Then those claims quickly collapse.

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  • $\begingroup$ All the past claims for the A380/A3XX being more fuel efficient, was wrt direct operating cost compared to the 744, with values of 10-15%, which makes sense and probably was achieved. Example: flightglobal.com $\endgroup$
    – user14897
    Jun 3, 2019 at 18:04
  • $\begingroup$ @ymb1: Yes, but the real competition is the 777-300 ER. The 747-400 flew 20 years before the A380 - of course those 20 years brought an improvement by 10-15% - something that the 747-8 also achieved. $\endgroup$
    – Peter Kämpf
    Jun 3, 2019 at 18:33
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    $\begingroup$ I understand fully, my point was I couldn't find such claim wrt fuel, only a smaller number wrt DOC. $\endgroup$
    – user14897
    Jun 3, 2019 at 18:39
  • $\begingroup$ I know I can always count on @PeterKämpf for a thorough treatment of issues like this! $\endgroup$
    – niels nielsen
    Jun 4, 2019 at 6:28
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    $\begingroup$ @ymb1: The 20% were the demand of Airbus management and of course quickly picked up by marketing early in the development of the A380. You are right that later, with better knowledge, claims of only up to 15% were made. $\endgroup$
    – Peter Kämpf
    Jun 5, 2019 at 22:34

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