Technology (Not Science)

[Kepler]

Yes, I would like my 3000 mph airplane, please.

 

[Swansong]

Lifting Body designs have been bandied about for many decades. The military uses them extensively. But the airline industry has rejected them over and over.

There's only so much room at airport gates. Larger planes already take up enormous space and that's with the current "tube with wings" design. They'd have to rebuild airports to accommodate such wide planes, and that... isn't very likely.

 

[Kepler]

Lifting Body designs have been bandied about for many decades. The military uses them extensively. But the airline industry has rejected them over and over.

There's only so much room at airport gates. Larger planes already take up enormous space and that's with the current "tube with wings" design. They'd have to rebuild airports to accommodate such wide planes, and that... isn't very likely.

90 minutes NYC to London. 3 hours NYC to Tokyo.

Rebuild the stupid airports.

 

[Swansong]

Well, I mean, yeah. But that article doesn't talk about the insane engineering issues inherent to air travel at that speed. Even things as seemingly simple as "what kind of fuel will this plane need in 15-20 years when it's remotely close to production?" - as there's already a slow push to get planes off current jet fuel and the redesigns necessary, as fuel prices increase and, hopefully, consumption drops.

Like, pretend we had some design where the external material could withstand mach 4+ temperatures and pressures, and that we use conventional jet fuel in these futuristic scramjet engines (of which there are no production versions currently). Where do you even store the fuel? In modern tube/wing design the fuel is mainly stored in the wings. How much maintenance is required for such abusive flights? Can we even fly it over populated ares? We couldn't fly the Concorde over mainland US/Europe... Then we get into economics. How many passengers would be required, at what cost? Would passengers accept being in the middle of such a wide area, nowhere near a window? Would passengers accept the likely high cost (relative to other planes) to save a few hours when just the security itself is a brick wall of unavoidable wasted time?


I dunno man. I love this stuff. Aviation endlessly fascinates me, All of it. The engineering. The science. The economics. The politics. The design. All fascinating. But short of some completely unforeseen development, we're sorta locked into tube/wing design for the short and medium term.

 

[Kepler]

Well, I mean, yeah. But that article doesn't talk about the insane engineering issues inherent to air travel at that speed. Even things as seemingly simple as "what kind of fuel will this plane need in 15-20 years when it's remotely close to production?" - as there's already a slow push to get planes off current jet fuel and the redesigns necessary, as fuel prices increase and, hopefully, consumption drops.

Like, pretend we had some design where the external material could withstand mach 4+ temperatures and pressures, and that we use conventional jet fuel in these futuristic scramjet engines (of which there are no production versions currently). Where do you even store the fuel? In modern tube/wing design the fuel is mainly stored in the wings. How much maintenance is required for such abusive flights? Can we even fly it over populated ares? We couldn't fly the Concorde over mainland US/Europe... Then we get into economics. How many passengers would be required, at what cost? Would passengers accept being in the middle of such a wide area, nowhere near a window? Would passengers accept the likely high cost (relative to other planes) to save a few hours when just the security itself is a brick wall of unavoidable wasted time?


I dunno man. I love this stuff. Aviation endlessly fascinates me, All of it. The engineering. The science. The economics. The politics. The design. All fascinating. But short of some completely unforeseen development, we're sorta locked into tube/wing design for the short and medium term.

I have a very stupid question. Would having a space plane that only does those speeds above the atmosphere eliminate the problem of needing a new material? (While I am sure introducing new problems.)

I'm assuming security theater isn't with us forever, in the same way that city walls weren't forever.

 

[Swansong]

Current production airplanes (excluding the military) use some combination of aluminum and composite material (and some steel and/or titanium) for their skin, so yeah. No plane in production or near-production has a skin material that could withstand the stress of high speeds or high altitude.


Again, even beyond the wonderful engineering problems (for which of course we can overcome if we so choose), remember that the Concorde and the proposed Boeing SST were ultimately ended largely due to economical reasons. It's stupendously expensive to blast people through the sky at that speed. It makes a staggering amount of noise. And people have grown to accept current air speeds and travel times. And with the rapid advancement in video communication and general data transfer, do you really need to go from NYC to London in 90 minutes?

 

[St. Clown]

Just because you were granted a patent, doesn’t mean your idea was actually a good idea.

https://www.threads.net/@iflscience/post/CwpbX8KsfmH/?igshid=MzRlODBiNWFlZA==

 

[dxmnkd316]

Subscribed

 

[MichVandal]

90 minutes NYC to London. 3 hours NYC to Tokyo.

Rebuild the stupid airports.

Why do we need that? And I doubt the 3 hours from NYC to Tokyo unless the plane spends most of it's time above 100,000ft, as you can't break the sound barrier over land- so much of the trip would not be fast.

But I still really fail to see the need of getting there that fast. For one thing, it will be really, really expensive- the plane will be a massive departure to construct it and the engines will need to be very new. So to just build the plane and keep it flying, it will be really expensive. On top of that, drag goes up so much with speed that the required fuel to get from A to B will be a massive increase. Basically, it will have to end up being just like the Concorde.

And for the nominal person, what's the point?

We need planes that are more efficient and cleaner not the opposite.

 

[dxmnkd316]

Why do we need that? And I doubt the 3 hours from NYC to Tokyo unless the plane spends most of it's time above 100,000ft, as you can't break the sound barrier over land- so much of the trip would not be fast.

But I still really fail to see the need of getting there that fast. For one thing, it will be really, really expensive- the plane will be a massive departure to construct it and the engines will need to be very new. So to just build the plane and keep it flying, it will be really expensive. On top of that, drag goes up so much with speed that the required fuel to get from A to B will be a massive increase. Basically, it will have to end up being just like the Concorde.

And for the nominal person, what's the point?

We need planes that are more efficient and cleaner not the opposite.

I guess my argument against that is why did we build passenger jets? Why not just take an ocean liner? Or a galleon?

 

[MichVandal]

I guess my argument against that is why did we build passenger jets? Why not just take an ocean liner? Or a galleon?

The difference between months and weeks was worth it, the difference between a week and a few hours is worth it.

Is the difference between 5 and 1.5 hours really worth it? Especially given the trade offs.

Especially since most of the "need" is for business travel, and much of business can really be done over the internet that it reduces the high profit need to the highest of the high managers. Which means it's a novelty for most of us, at best.

 

[Swansong]

The difference between months and weeks was worth it, the difference between a week and a few hours is worth it.

Is the difference between 5 and 1.5 hours really worth it? Especially given the trade offs.

Especially since most of the "need" is for business travel, and much of business can really be done over the internet that it reduces the high profit need to the highest of the high managers. Which means it's a novelty for most of us, at best.

This is a huge thing, in my opinion. To wit: in the 1960s we really pushed supersonic flight for bombers and spy planes, right? We got some great jets and incredible research out of them. But the XB70 was shelved and the SR71 only used by the CIA. Why? Both had major issues that were in the process of being worked out (or worked out to an acceptable level in the case of the SR71). But Just as the XB70 was really starting to get sorted out, ICBMs came online. And suddenly you don't need a jet to deliver that first strike. And once spy satellites really came into their own, the SR71 was retired (yes we still use newer versions of the U2, but that isn't remotely fast).

I see the same thing with supersonic passenger flight. Society has accepted current flight times (customer service, comfort, scheduling less so), and with the rapid advancement in collaborative technology (zoom, office365, etc.) I just don't see a huge demand for economically sustainable supersonic flight. Smaller scale, supersonic business jets? Yeah sure, probably. But 200+ passengers that need to get 8000 miles in 3 hours that are willing to pay the accompanying cost? No.

 

[joecct]

The difference between months and weeks was worth it, the difference between a week and a few hours is worth it.

Is the difference between 5 and 1.5 hours really worth it? Especially given the trade offs.

Especially since most of the "need" is for business travel, and much of business can really be done over the internet that it reduces the high profit need to the highest of the high managers. Which means it's a novelty for most of us, at best.

Great point. As a counterpoint, if you are going from DC - Hawaii, it's a 10hr non stop flight with a 5 or 6 hour time difference. That's a lot of jet lag. Getting there 3x as fast would help.

 

[Swansong]

Great point. As a counterpoint, if you are going from DC - Hawaii, it's a 10hr non stop flight with a 5 or 6 hour time difference. That's a lot of jet lag. Getting there 3x as fast would help.

Oh hell yeah it would. But again, sonic booms are illegal over the continental US. So you'd need to change that law or fly high enough to avoid them.


Frankly, I'm not sure which one would be more difficult.

 

[MichVandal]

Great point. As a counterpoint, if you are going from DC - Hawaii, it's a 10hr non stop flight with a 5 or 6 hour time difference. That's a lot of jet lag. Getting there 3x as fast would help.

But you can't go that much faster the entire way. So the improvement won't be that much. Besides, going west, the 10 hour fight with a 5 hour time difference ends up being a 5 hour loss. Going west is always easier than going east for jet lag.

And 3x faster is 9x the fuel, since drag is the square of speed. And drag is where the fuel is used. Fuel is most of the flight cost, so would you be willing to pay 9x the fare?

 

[Kepler]

sonic booms are illegal over the continental US.

I have a dumb question. Sonic boom occur when you break the sound barrier. Does anything happen when you drop back under it?

Edit: it really was a dumb question.

A sonic boom does not occur only at the moment an object crosses the sound barrier and neither is it heard in all directions emanating from the supersonic object. Rather, the boom is a continuous effect that occurs while the object is travelling at supersonic speeds and affects only observers that are positioned at a point that intersects a region in the shape of a geometrical cone behind the object. As the object moves, this conical region also moves behind it and when the cone passes over the observer, they will briefly experience the "boom".

So. Never mind.

 

[LynahFan]

This is a huge thing, in my opinion. To wit: in the 1960s we really pushed supersonic flight for bombers and spy planes, right? We got some great jets and incredible research out of them. But the XB70 was shelved and the SR71 only used by the CIA. Why? Both had major issues that were in the process of being worked out (or worked out to an acceptable level in the case of the SR71). But Just as the XB70 was really starting to get sorted out, ICBMs came online. And suddenly you don't need a jet to deliver that first strike. And once spy satellites really came into their own, the SR71 was retired (yes we still use newer versions of the U2, but that isn't remotely fast).

I see the same thing with supersonic passenger flight. Society has accepted current flight times (customer service, comfort, scheduling less so), and with the rapid advancement in collaborative technology (zoom, office365, etc.) I just don't see a huge demand for economically sustainable supersonic flight. Smaller scale, supersonic business jets? Yeah sure, probably. But 200+ passengers that need to get 8000 miles in 3 hours that are willing to pay the accompanying cost? No.

Agree with all of this. Just a nit that I don’t think anyone is contemplating 200-seat cabins. The most ambitious player today is Boom, and they’re looking at 55 to 75 seat cabins. Their sweet spot is really the NYC/BOS to LHR/LGW market, where it really would be possible to fly over for a lunch meeting and then return to sleep in your own bed that night.

 

[MichVandal]

I have a dumb question. Sonic boom occur when you break the sound barrier. Does anything happen when you drop back under it?

Edit: it really was a dumb question.



So. Never mind.

Sorry, but that's not a dumb question. Doing the research you did, it became obvious why supersonic flying over land isn't legal. So it was far from a stupid question.

 

[Kepler]

Sorry, but that's not a dumb question. Doing the research you did, it became obvious why supersonic flying over land isn't legal. So it was far from a stupid question.

Oh, I get why it's no bueno, but my mistake was thinking the boom is one and done. It's a persistent phenomenon and the answer to what happens when you drop back under is simply "it stops."

True, it wasn't a dumb question, it was an ignorant question, and now I'm all edumacated up.

Also: edumacated does not show as a misspelled word, which means either it was in the dictionary or at some point I added it.

 

[LynahFan]

Why do we need that? And I doubt the 3 hours from NYC to Tokyo unless the plane spends most of it's time above 100,000ft, as you can't break the sound barrier over land- so much of the trip would not be fast.

But I still really fail to see the need of getting there that fast. For one thing, it will be really, really expensive- the plane will be a massive departure to construct it and the engines will need to be very new. So to just build the plane and keep it flying, it will be really expensive. On top of that, drag goes up so much with speed that the required fuel to get from A to B will be a massive increase. Basically, it will have to end up being just like the Concorde.

And for the nominal person, what's the point?

We need planes that are more efficient and cleaner not the opposite.

Like this one:

DAF selects JetZero to develop blended wing body aircraft prototype > Air Force > Article Display

(Disclosure: my company, Northorp Grumman, is a partner on the project)

The US Military consumes 10% of the US's jet fuel. According to the article, mobility (cargo + tankers) aircraft use 60% of that fuel. If BWB's could cut drag by 30%, that cuts US jet fuel usage by 1.8%. Once the type is in service, it should be a no brainer for the commercial cargo market - dollars and cents matter. Commercial passenger is a tougher sell - people like there being windows, but realistically, if you're in the center seat of a 3-5-3 777, you already can't see out the window and people accept that, so I think it could catch on.