Boeing to build braced-wing airliner, shooting for 30% efficiency gain | Hacker News Reader

Boeing to build braced-wing airliner, shooting for 30% efficiency gain

newatlas.com

Speaking of future aircraft - what's interesting to me is they do not seem to be planning on any more composite barrel aircraft after the 87. Even 777x is only graphite wings, no graphite barrel, which seemed to me like the natural next step. I wonder if it is manufacturing capability related, or if they regret the amount of R&D it took to get the 87 barrel to viability, or some other reason?

The A350 has composite panels and one barrel component iirc, which is a step above what the 777x is doing.

I know BA had a Next Generation Aircraft project looking at a fully composite 737 replacement, but that didn't proceed anywhere either. The braced wing design is pretty wild, but at least they will have plenty of room to make the engines larger...

I think there are a few things behind this:

1. price. Carbon fiber is a lot more expensive than aluminum

2. The wings are the parts that need the most strength, and where the flexibility of design helps the most.

3. Making a giant tube of aluminum is a lot easier than with carbon fiber, but the complex shape of a wing evens the cost more

4. Carbon fiber advantages shrink with larger aircraft since making the ovens for really big carbon fiber parts is ridiculously expensive. I wouldn't be surprised if smaller planes go to all carbon fiber before bigger ones.

I watched Scott Manley's video [1], and he only mentions 10%. I don't think 10% is anything to sneeze at. No need to pump it up to 30%.

[1] https://www.youtube.com/watch?v=Xm5LYkGHkTc&t=704s

Great video. I don't understand why they're looking at transonic speeds and calling it a transonic demonstrator. Airlines travel slower these days to save fuel costs.

Edit: also, why does this have to be a full-sized demo? Can't a half-size demo do a sufficiently good job?

I assume smaller braced wing planes have already been made in the past, so making another similar scale one wouldn’t tell you anything new? Presumably the engineering challenges here are related to the scale of the craft now rather than other issues?

Amazing that there is so much performance left on the table, in what I thought was a pretty mature field.

Why is NASA pumping money into Boeing? Isn't NASA's money mostly from public funding? Boeing on the other hand is a dying company.

It seems to me that plane could not make a survivable water landing, though I doubt that’s a criterion that airliner designs are judged by.

I wonder if Boeing still have it in them to do something like that, after the last string of debacles.

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