Interesting historical note on the blended wing design:
One of the main arguments against it was that designers weren't sure if people would be ok with sitting towards the center of the plane. The thought was that passengers wouldn't be comfortable without being able to at least see outside (even a little, looking at you 3/4/3 widebody planes).
I mention this b/c there is a quote in Mary Roach's Flying to Mars. She mentions concerns around how astronauts will be able to psychologically handle the remoteness of space. As a similar example. they talk about how in Victorian England people were concerned that trains would be traveling so quickly that it would induce a state of shock in the passengers. This turned out to not be the case at all.
In fact, she quotes a cosmonaut who says "Only people think this is problem is psychologists".
A bigger problem with blended wing designs is actually for the people on the peripheral. When the plane banks, passengers further from the axis of rotation will feel a more significant change in their altitude. You literally feel like you're "falling", as the plane banks to your side.
This also applies to existing aircraft, but the amount you drop/rise is limited by the your distance from the axis of rotation, which is normally not very far. In blended wing designs, the distance could be considerably greater, making this sensation much more intense.
The workaround for this would be to simply use shallower bank angles, but I suspect that would require some pretty major changes to navigation rules, as it would drastically increase the turn radius.
> A bigger problem with blended wing designs is actually for the people on the peripheral. When the plane banks, passengers further from the axis of rotation will feel a more significant change in their altitude. You literally feel like you're "falling", as the plane banks to your side.
This is a problem that a market can easily solve: make the more central seats more expensive than the outer ones. If the pricing is right, the demand for the various kinds/positions of seats will be balanced.
P.S. I can actually imagine that there do exist people who prefer the outer seats because they like the acceleration that makes the flight feel more like a carnival ride. :-)
Totally on board with flying in the outboard cheap seats, at least for any flight where I don't have to sleep. Flights are incredibly boring aside from takeoff and landing, and I love roller coasters. :)
I have a feeling there are enough of us to make it work in the market and still fill planes, just instead of first-business-coach going front-to-back it'll go center-out, like a theater.
The issue isn't the bank angle exactly, it is the acceleration of the roll. Pilots will need to be careful not to throw people or drinks around, but I think it would be doable.
I think that would be tough. Out in relatively empty airspace, sure, the pilot can make pretty slow turns. But major airports with multiple runways, other airports in the vicinity, military bases, etc, all put hard requirements on the flight corridor. Sometimes the pilot has no choice but to make pretty sharp turns, and that means a pretty fast roll acceleration.
The issue isn’t the bank angle but pitch acceleration felt by the passengers when they pilot wants to bank for a turn. Which opens up several methods to compensate.
You could for example more slowly enter a higher bank angle to have an equally fast turn though passengers would feel more pressed into their seats etc.
Turbulence causing roll upsets seems like it could be a larger issue.
How about... more rudder? Of course, more control surface area means more drag and less fuel efficiency. Wonder if a flying wing style craft that has enough rudder to match traditional cylinder fuselages bank-and-yank capabilities is still more efficient.
Lid or no lid, it’s still a problem if your drink falls off the tray table. Which is one of the reasons they say to put your tray tables in upright an locked position.
But even beyond that feeling like you’re falling out of your seat is unpleasant.
Automakers solved this problem many years ago, by making cupholders that are deeply recessed instead of thinking that cups wills somehow magically stay in place with a very minimal indentation (see the "cup holders" on the backsides of glove compartments in 1970s American cars).
Commercial aviation could stick as many as 850 passengers on an A380-800 in it’s maximum configuration, but the most an airline actually gets is 538 because of business and first class passengers having more room. Increasing passenger space by even 1 inch or just a pound of weight per seat makes a real difference.
Better cupholders do not decrease space at all. Some (better) airlines even have them: they flip down from the seatback. They literally take no space at all. This is ridiculous.
True, but absolute bank angle would also matter (say endpoint of roll when roll acceleration is zero) because now there's a component of gravity pulling you sideways.
When roll acceleration is zero, the remaining acceleration (i.e., due to gravity) felt by a passenger on the wing edge will be the same as a passenger in the middle of the plane.
The plane turns while banking which results in a force vector mostly straight down towards the floor. If the plane did not turn while banking what you wrote is true.
A coordinated turn with 60 degrees bank should be achievable by any airworthy airplane (it requires pulling 2g), and the maximum bank angle for a steady-state coordinated turn depends on how many g you can pull before you run out of control authority, cause an accelerated stall, or reach the airframe's structural limit.
Next time you fly, get a beverage of your choice and observe how it behaves. Here's an example, courtesy of the great test pilot Bob Hoover:
If the turn is coordinated you can't tell the difference. I've been in small GA planes turning at 35-40 degrees and it doesn't feel like you're sliding at all, you're pulled back into your seat and "down" (relative to you) into the flooring.
I'm not sure this tracks, I think turbulence powerful enough to cause passenger discomfort is usually so big that it affects the whole plane pretty uniformly. I think it's exceedingly unlikely that you'll spend enough time on a shear line to induce a large roll.
At least it's never happened to me, but I am only a passenger.
I've been in turbulence with high roll rates and even as a pilot unbothered by moderate chop, it will cause me to sweat. I've been in the last rows of a 777 and watched the fuselage flex in chop. A blended body would be pretty rigid and have a very low wing loading because it's basically all a wing. So it would be pretty uniform.
It would work if all turns were managed via controls to be a 1/4g, otherwise riding the outside would be like a roller coaster.
I'd prefer to go back to the MD-80. Very high wing loading, fast and never broke down. Skated through turbulence.
The DC-9 and MD-[89]X were great airplanes. One of the great tragedies of unchecked American corporate consolidation/acquisition is that Boeing was allowed to borg McDonnell-Douglas. (Although some climed the opposite was closer to the truth...)
Anyway, the resulting company is too large to fail, and thus, too large to exist. We're at a point where we could really use the competition we had in aerospace companies back in the 80s, when there were enough competitors in both military and commercial aviation for competitive pressures to keep the players working to provide innovation and value. (Rather than milking the market with intentionally poor designs a la Boeing's 737MAX.) Modern airlines have only two vendors to choose from now that Boeing and Airbus have gobbled up even their second-tier competitors.
Personally, I'd love to see what the old Convair, LTV, pre-Martin Lockheed, or pre-McDonnell Douglas might come up with in this competition...
The problem is that, what airlines want, and what regulators want, is now too expensive to independently develop and start a new competitor for, even if you are well resourced like China, Japan or Russia (which all have attempted and failed to break into international aviation sales).
A new aircraft development is a $15B+ R&D investment, for the price and fuel efficiency and safety required. McDonnell-Douglass and more recently Bombardier messed up their bets and it cost them their independent existence.
can't speak to aeronautics of it, but from a pax perspective, the md80 was a fantastic jet. probably the last vestige of what flying "used to be like" since they were too old to retrofit for "efficiency". also its planform looked AMAZING; retro-futuristic even
closest modern aircraft to it is the 717/MD90, which Delta is still flying, but not for much longer iirc
Yes a blended wing would be stiffer, but wing stiffness isn't really relevant here. The wing bending isn't evidence of differential pressure between the two wings, it's only showing that the wings are the part of the plane that's most affected by turbulence while not accounting for the majority of the inertia.
The point is that air currents powerful enough to appreciably affect a large plane are large scale and therefore you're unlikely to have enough differential pressure from one wing to the other to impart much torque.
I'm not certain about this and I'd love to be corrected if I'm wrong.
Ah, so in other words the whole plane bumps up and down but doesn't rotate. Therefore the location of passengers doesn't matter much, as all locations experience the same acceleration. (Provided the cabin is stiff)
When I was younger, watching the wings flex up and down in turbulence was one of my favorite things about flying, like an amusement park ride. Over the years my perspective has changed.
you could also put the passengers more towards the middle and the fuel / cargo on the tips. Doesn't solve the problem and balance would be tough I imagine.
>This also applies to existing aircraft, but the amount you drop/rise is limited by the your distance from the axis of rotation, which is normally not very far.
When a plane is crabbing, as in coming in sideways towards the runway, when it touches down, and suddenly pivots to normal runway directions, even passengers in the rear of a normal plane, might be accelerated hard around the yaw axis.
That's called a "coordinated turn", and it's what airline pilots should be aiming at whenever possible. In a coordinated turn, "down" remains aimed at the floor, regardless of actual bank angle. There's even an instrument (the turn-and-bank indicator) designed expressly to help pilots execute coordinated turns, which are generally considered a mark of a capable pilot in any plane...
Does this mean if a blended wing plane banks hard and you stand up on one side of the plane you could potentially jump your way across to the other side a bit?
I'd image the biggest reason is that risk tolerance is lower for cargo companies than for passenger airlines, and that cargo companies are more inclined to run a subset of their fleet as an "experimental" model vs the consistency that passengers expect. They probably also have the biggest potential gains given there's only so tight you can pack people.
My understanding is that having to manufacture a different rib for each station along the structure is a significant challenge. It's possibly less of an issue with composites?
The differences in ribs across the span of a wing are much less of an issue than compound curvature in the wing skins—this is where composite manufacturing really shines, because you can mold them into arbitrary shapes.
The expensive part of composite aerostructures isn't making them, per se, it's the molds and tooling you have to build first, and you need a lot more of those when contours are constantly changing. (This isn't new though - continously changing contours have been the norm since the first high supersonic wasp-waisted "area rule" fighters and bombers appeared in the 50s and 60s.)
That said, I was working on B-2 aerostructures in the late 80s, and I can tell you that most all the parts on that plane have no symmetry in any direction other than centerline bilateral. My group figured we could save over $10 million each on a single B2 duct, if we could change the bizarre geometry to simplify the scary complex tooling it required. That was enough potential savings to provoke a design review, but the answer came back, "Nope. It has to be that way (we presumed for stealth). Go figure out how to build it..."
Because the fuselage is pressurized. And it is convenient to have pressure vessels as cylinders for even distribution of of the pressure forces across it. Ideally you want to have it capped off with two hemispheres (think propane tank shaped) but obviously you can't do that for other reasons. So there is likely more design and manufacturing for the front and rear of the plane than the main section.
Ah, gotcha. Yeah, there’s zero chance that you can make a pressurized pancake using rib-and-stringer architecture, probably even out of unobtanium. The best candidate I can think of is making it like a submarine, although that would definitely mess with the open concept floor plan and probably impose a huge weight penalty (although it might be helpful from a fatigue life standpoint). The only other remotely viable solution I can think of is drop stitching, but that has some fairly obvious drawbacks that would probably make it impracticable.
Another problem is how planes are designed for different sizes.
Say you design your plane with the base / most ordered as the dash 9.
Now someone wants a smaller longer range one.
just take some fuselage barrel sections out. Boom dash 8.
Want an even smaller one. Take more sections out. Dash 7.
Need a huge massive super long range one with loads of seats.
Add sections and you get the dash 10 or 11.
Current planes use a uniform fuselage structure for this reason. You're going to make different models within the same model family with a flying wing.
My experience as a frequent flyer is that First Class is the most likely cabin to have all windows closed for 100% of the flight. It's baffling to me, people will even keep closed the window facing New York on the approach to LaGuardia which should be a crime. Also Boston, Salt Lake, Hawaii, and really pretty much all places except like Dallas and Cleveland types totally perplex me when the window is closed and I'm not directly next to it. I want to witness this glorious rock from above!
This always baffles me flying out west. I mean Nebraska, Kansas, Iowa - i get it - close those windows we can sleep. But the Rockies, Mt St Helens, Mt Hood, Mt Rainier...and then you hit the mfin GRAND CANYON and you still wont open up your window?!?! people that don't open their window over the grand canyon need to be put on a list for middle seat only.
I am regularly on flights which go over the Grand Canyon. On that flight specifically, I keep my window shade open for the sake of the folks in the middle and aisle seats.
Of course, they are probably thinking "wish that view didn't have that sleeping dude in the foreground".
i flew business to hong kong a few years ago and i couldn't put the shades up AT ALL because of people sleeping most of the flight, which sucks because from the crack I was able to see through, we passed through some incredible shit
I see this more and more everywhere across the plane these days.
I remember flying as a kid/teen and nearly every window was open during takeoff and touchdown. Last 3 to 5 years and almost every flight has had less than 10% of the windows open. I don't get it - I also want to see it. We're fucking flying, for god's sake.
They used to ask you to open the window shades for takeoff and landing, idea was to actually be aware of what is going on outside incase an evac is necessary.
Now they ask everyone only to close the window shades after landing to better control the temp, the APU a/c is often no match for direct sunlight. Then most people just leave them closed.
And once upon a now long time ago, when I was a boy, the food was actually hot, quite tasty, prepared by actual chefs, and served on real china dishes with metal silverware. (Even in Coach - it was many years before I travelled enough to get a few upgrades to First Class!)
Modernity and MBAs have stolen the elegance and service that flying (or the train, to an earlier generation) used to have when America was great. I remember marveling that as expensive as such flying was, it was really not a bad deal to get a great meal served by pretty young women looking over such amazing vistas, with fast, smooth transportation thrown into the bargain!
I thought I was the only one who experienced this.
I race cars as a hobby but I suffer from motion sickness whenever I’m not driving or whenever I can’t see out. People will choose the window seat and keep it closed the whole time. WHY?! At least open it when we’re on the ground being shaken back and forth while backing out and taxiing so my mind doesn’t lose point of reference.
Back before the in-seat video days, I was flying back from Europe to the US. We were just approaching the coast of Greenland. I could see icebergs in the water, and glaciers coming down to the ocean. Then they asked us to close all the windows so people could see the in-flight movie. And I'm like, when am I going to see Greenland again? I can rent the movie.
I flew relentlessly for work for years and the view out the window of the plane was the one thing that never got boring or I took for granted. Actually, add lie flat seats. Everything else definitely became part of the wallpaper.
It... might have something to do with a psychedelic experience I had on a plane once...
I get this, but also peering out a narrow plane window at a view which is often at least substantially blocked by wing is not always fun.
I would like airlines to put a 360 degree camera system mounted to the exterior, and pipe through the feed either to a channel in an in-seat screen, or make it available to passengers wearing a VR headset. Imagine one of these much wider planes where many more seats are middle seats -- but where you can sit down, put on a VR headset, and get a clear image of the view in every direction.
If fewer people will have a window in these future planes, and most awake people are looking at an entertainment system anyways, I would like the airline to pipe through a feed from a 360 degree camera mounted on the outside. Imagine sitting in a middle seat, comforted by the fact that you can put on a VR headset and
I'm claustrophobic. Having the window there and next to me is essential for me. Mentally, i need to feel like there's an exit i can jump through if things go awry. Of course, thats not realistic. But some artificial screen doesnt give me the same comfort. Looking out and see the outside for myself is the only thing that does it
People seem to prefer either the window or the aisle. You go and select seats, and it's always the middle seats that are left over. So it might be an issue if these new plane designs have lots of middle seats. They might have to give more space to the folks in those seats to get them filled.
If that were true, why would the person be on the plane in the first place? Couldn't they just watch a movie of their destination or zoom call the person they were visiting from home?
> If that were true, why would the person be on the plane in the first place? Couldn't they just watch a movie of their destination or zoom call the person they were visiting from home?
It can be the case that both:
* watching a video of the plane moving through the air is an effective way to mitigate some of the discomfort of flying
* meeting face to face with someone is valuable enough that it's worth taking the flight
? people go on planes to get to places not to experience flight itself per se. i don't mind sitting in an enclosed room for x amount of hours while it gets me half-way across the world for cheap
Personally, the only things I care about in a plane are safety (by a wide margin), comfort, and price. I spend all my time listening to music with my eyes closed or watching movies anyway, and the window doesn’t give me much.
Maybe just put a bunch of cameras all over the exterior so the passengers can see what’s going on wherever they are sitting.
I hear you. But the first time I did a polar/Hudson Bay flight between Europe and west coast USA, I was transfixed by the view out of the window. I’m very happy to have seen that extraordinarily beautiful view.
Cameras would be some compensation, but the direct view is amazing.
Arguably not as spectacular, but I relish every city approach. The serpentine Thames as you stack over Heathrow, the mountains of Vancouver, the insane scale of Tokyo: I value fuel and cost savings, but I hope there will always be opportunities to experience these wonderful views.
Planes have a huge impact on both the climate and economy, and I don’t think the joy of occasional sightseeing is a strong enough argument against pursuing efficiency gains.
The main argument against it is that it increases fuel consumption. Plowing your cargo area through the air sideways is just idiotic. There is some crazy public belief that it is more fuel efficient because the public doesn’t understand physics. These things keep getting getting publicity because even Hacker News folks don’t get it.
Long high aspect ratio wings and streamlined body are how you get fuel efficiency.
The fuel burn of a B2 is far higher pound for pound than a 737.
This idea gets even more ridiculous when you consider the cargo area is a pressure vessel. There is a reason the body is isomorphic with a welding tank.
Edit: I suppose I wouldn’t care about this, but the Biden Administration plowed climate money into a blended wing military concept, which 1 day with any CFD software shows is stupid.
It’s not that simple. Aerodynamic drag is made up of surface drag and induced drag. Given the same coefficient of drag, drag goes up as S-wet goes up (which is what you’re referencing). Induced drag is a consequence of how much structure is required to create a flying vehicle. IF (and it’s a big if) the BWB turns out to be more structurally efficient, then the total drag for the plane might be less than for a conventional design.
(Source: I have an aerospace engineering degree from Embry-Riddle)
> There is some crazy public belief that it is more fuel efficient
There are a number of engineers at NASA and Boeing working on the X-48 who would disagree with you on this one.
The main advantage of the blended wing body is to reduce the skin friction drag [0] of the aircraft relative to the typical fuselage and wings. You have less surface area in contact with the air relative to the amount of internal volume. There may be some increase in the profile drag (i.e. the cross section of the aircraft) but is made up for by the reduction in the skin friction drag.
> The fuel burn of a B2 is far higher pound for pound than a 737.
This isn't really a fair comparison. They are two aircraft optimized for entirely different things.
Skin friction drag is a drop in the bucket compared to parasitic and lift induced.
I’m willing to accept that a gold bullion transporter can look closer to a flying wing, but with any reasonable cargo density you are back to the standard design.
Trying to intuitively explain CFD results is apparently just as hard as dispelling the Bernoulli nonsense about airfoils.
I’m right and high aspect ratio wings are a harder materials science and design challenge than blended wings. There is a reason 10000x as much engineering effort is going into folding carbon fiber wings for passengers/cargo. The folding is to increase fuel economy through aspect ratio and fit in terminal box.
Everything I have said is trivial to prove with CFD and experimentally. I get that popular science articles need to entertain the masses.
Let me ask you this, why is the tail of passenger aircraft upward sloping?
One, I'll admit I'm not an expert in this, I have an aerospace degree and took some aircraft classes but it was 90% on the space side of things. But I'm trying to be devils advocate here since its not just pop-sci articles.
> Skin friction drag is a drop in the bucket compared to parasitic and lift induced
I'm trying to rectify it with papers that say "In civil aviation, skin-friction drag accounts for around 50% of the total drag in cruise conditions" [0]
> I’m right and high aspect ratio wings are a harder materials science and design challenge than blended wings
I understand that higher aspect ratio reduces drag too and that the planes should all look like scaled up gliders with their long skinny wings. But as you said, it is harder. So is it a clear cut answer that exploring blended wing designs is a waste of time?
> Let me ask you this, why is the tail of passenger aircraft upward sloping?
To prevent tail strike during take-off and landing when you are at a high angle of attack.
Long thin fuselages dramatically increase drag due to skin friction. Blended wings have better lift to drag ratios, meaning for a given amount of fuel consumption (to overcome drag) you get higher payload/better range.
The B2 has twice the range of a 737 and cruises 20% faster.
I mean, aerodynamic drag scales linearly with both Cd and A. It isn’t too far-fetched to think that you might be able to trade them off in a blended wing design and come out ahead by reducing interference drag and wetted surface area.
The pressure vessel problem is much more concerning to me—I can’t think of a way to solve it that wouldn’t massively increase weight and/or reduce usable space.
To be fair, the B2/737 comparison isn’t particularly fair—they were optimized for wildly different things, and only one design was significantly constrained by acquisition and operational costs.
Goose wash is the problem with single file. Goose V takes advantage of the up current you get from the neighbors lift. Geese and evolution clearly understand areo better than current HN.
Do you have any sources for this? My understanding is that hybrid wings reduce weight needed for structural components. Since fixed wings basically trade drag for lift, reducing weight can more than offset increases in profile/shape that increase drag.
The problem is frontal area is higher, so more drag. Wetted area[1] is also much higher, so there's a lot of skin friction.
The advantages are (theoretically) lower structure mass per passenger. But airplane cabins are pressurized, and lightweight pressure vessels 'want' to be cylinders or spheres, not big flat boxes.
There's a aerospace engineering student who gave a thesis talk on the disadvantages of blended wing-body, and offers some possible solutions.[2]
I'm no aerospace engineer, but the flux through the air, driving resistance, seems obviously higher the more you move away from the shape of a missile.
If you put them in a central "barrel" like in a current plane it would be a bad use of the available space.
Yet you can't do otherwise. Because of the heavy banking when the plane turns, you can't seat people far away from the central axis and closer to the side edges of the V shape.
Interesting point. Cargo and fuel should be placed on the far sides. Passengers towards the center, perhaps on two levels. Routes could be adjusted to decrease typical bank angles.
Makes me wonder if we'll have cargo-only planes that converge on a different optimum. In full autonomous mode, comfort is not a factor and reliability can also be relaxed. Of course, we'd lose the flexibility of being able to convert the plane for passenger service.
Bank accelerations must be limited, not angles. You could do a full roll without noticing if the acceleration vector pointed mostly through the plane’s floor.
Would this likely become a dangerous "recovery" scenario with the plane spinning around on the center axis and accelerating directly towards the ground? This sounds dangerous for any passenger aircraft.
To be clear, I am against flying passengers into the ground.
Pilots don’t tend to roll passenger aircraft. But given enough altitude and skill they probably could without spilling a tomato juice on a seat back tray table.
Why would reliability be relaxed? Other than just being silly on the face of it reliability is still important in cargo. It's even more important in the perception of aviation.
For the same reason we don't cover cars in 3" thick steel armor. It's still very important–planes and cargo are expensive. But overall cost might be optimized without quite as many zeros.
No they aren’t. Airplanes like boats are certified in such a way that the regulations assume that all future airplanes will look like past airplanes.
As such any deviation from that standard form is super expensive because you need to have the regular create an updated set of rules. That takes years and years and tons of money/risk
It may make sense from a physics point of view but not from a business view.
Same thing happens with construction planning - very hard to get anything “unusual” through planning departments if it doesn’t just conform to existing methodologies, design, and often even size. Hence why movements like the tiny house movement have such a hard time - the rules were designed when building was affordable - now it’s not.
Take a look at 14 CFR Part 23. The standards are performance-based. I don’t think I’ve ever seen any kind of proposed aircraft design that doesn’t fall into existing categorization.
I remember seeing renderings precisely like this in my middle school textbooks in the 90s, claiming the same thing. The truth is that commercial airliners are a solved engineering problem. We are at the absolute limits for speed, reliability, and safety that can be achieved with a flying machine in the earth’s atmosphere. Which is why the fundamental layout has not changed since the 707 was introduced over 60 years ago.
Blended wing designs fall short on many of these constraints, namely the complete lack of inherent stability. With total power loss, they become completely uncontrollable. This is an acceptable tradeoff for military aircraft (modern fighters have the same issue), but not for civil aviation.
Yup, I've been seeing these futuristic airplane concepts for most of my life, but commercial airframes seem to be converging to be more and more similar. Unusual elements like a third engine in the tail or horizontal stabilizers mounted above the rudder have largely disappeared. Given the thin margins in air travel, I suspect this is because this design is the most successful. It might be a local minimum, but when it comes to these radically different designs: "I'll believe it when I see it".
My understanding is that tri-engine jetliners were actually more to fulfill a regulation than for engineering reasons. There are regulatory limits to how far a plane is allowed to fly on one engine called ETOPS - I forget what it really stands for, but the colloquial expression is: Engines Turn Or Passengers Swim. It used to be limited to around 2 hours I believe, meaning you've got a bit of time to divert and make an emergency landing. But if you're crossing the ocean, it's not really possible, so for a long time if you were crossing an ocean, you needed a 3 or 4 engined plane to do it.
Jet engines are extremely reliable however, they fail on the order of several hundred times less often than piston engines, and are very well proven and have basically only improved, and so ETOPS rules have been relaxed quite a bit meaning that a lot more ocean crossing routes are available to twinjets.
Yes, ETOPS ratings have been extended as engines have gotten more reliable.
Another factor is that we have learned to make bigger engines as well. So nowadays with two engines you can power a pretty big plane. And due to how turbine efficiency tends to scale with size, two big engines is more fuel efficient as well as saves on maintenance costs vs. having more but smaller engines.
For an extreme example, look at the B-52 with 8 engines. That was what was available back when the plane was designed, but nowadays the thrust from those 8 engines (about 600kN in total) can easily be exceeded by two modern large turbofans.
Horizontal stabilizers above the rudder went away with the engines mounted on the body in the back, the reason for the high tail was to keep the elevators away from the jet blast of the engines.
As to why create a design like that in the first place, I don't know. My understanding is that the 'engines under the wings' layout won because with the engines in the back the fuselage needs to be stronger (and thus heavier) to support the engines.
(Business jets tend to still have the engines in the back layout, because mounting the engines high allows shorter landing gear so that a stair that is part of the door is enough to board the plane, no need for an external stair. But that's not much of a consideration for a passenger plane operating out of airports with infrastructure available.)
A lot of the reasoning for business/regional jets maintaining the high tail mount engine layout is FOD avoidance. Operating out of shorter runways/smaller airports this becomes an issue.
Isn't much FOD ingestion due to the wheels kicking up something? If so, mounting the engines in the back seems like a bad idea, as even if they are higher up than an under wing mounting there's a risk that the wheels might kick up some debris?
From a FOD perspective, in my admittedly very non-expert opinion the best location would be to have either a high mounted wing with engines in the traditional under wing position, or then engines above the wings like the Honda business jet?
Came to the comments to make nearly the exact same remark. I, too, remember seeing these in middle school in the 90s, as well as high school. Though, they weren't in my textbooks - but were in the supplemental "educational magazines" that the science teachers would supplement their coursework with, and "Popular Science" magazines that the school had in the library.
Note that this entirely powerless aircraft with a fairly high aspect wing and no tailplane first flew in 1968. Something that is basically a blob would be a lot easier to make inherently stable.
The article states that other designs are being looked at due to improvements in other areas, namely sustainability and suitability to alternate fuel sources. I would think that if you had a design that came close in reliability and safety, sacrificing speed for better efficiency would be a good tradeoff on many commercial flights with passengers or cargo.
No. commercial airliners are only a solved problem if you ignore the climate crisis. There is no way you can run the current design on electricity during intercontinental travel. This is the problem that engineers are trying to solve with innovative and radical design changes.
Puff piece as we head into the weekend. Not a bad summary of decades old concepts, but Boeing won't touch these things due to shareholder conservatism even though they are fundamentally better than the tube with wings. If there were a SpaceX of commercial jets, this is what they would build.
I was going to call it a puff piece, but as far as Boeing is concerned:
> Boeing won't touch these things due to shareholder conservatism
My spouse worked for Boeing. My son currently works for Boeing. Change is the slowest and most difficult thing to bring about at Boeing. It’s part of Boeing’s DNA.
Exactly. I worked for Boeing as an intern and the entire industry is like this. It's basically 90% of aerospace, outside of the startups, is like IBM, Oracle. These companies have extraordinary history (facilities from WW2! god damn museums with their products! rise and fall tied with global geopolitics, seeing armed security and international VIP's at the guarded entrances) but will never innovate unless put up against a wall.
At my university, wind tunnels had a black curtain that could be used to conceal the test section contents. During the Cold War, they used it to prevent casual onlookers from witnessing confidential design work for the govt.
> Engineers are exploring radical new designs for commercial planes that would use less energy and lower emissions. But will passengers be willing to board them?
They don't really explore the question in this subtitle very well. There's like one line late in the article about "passenger acceptability is one of the criteria built into its contest", so the short answer must be yes.
I assume the longer answer is "Yeah, of course. Passengers of commercial airlines already put up with a lot of terrifying, uncomfortable, dehumanizing things, there's no reason to suspect they'd be so spooked by airplanes that look different that they decide never to travel."
Yeah, I always roll my eyes at the phrase "passenger acceptability." For example, a few years ago there was this idea that passengers would not fly on the 737 Max after it re-entered service in the US. Which is nonsense since I'm willing to bet that 90% of passengers can't identify if the plane they're on is Boeing or Airbus let alone care about individual models. The only "passenger acceptability" metric is what does the ticket cost?
"New" designs. Ok. Pretty sure variations on most of these have existed for decades. There have been tons of radical looking aircraft designed and even in limited production (in private aviation), but just because it's radical doesn't mean it's really new.
The thing that shocked me about this documentary about the 747 is the claim that they went from napkin sketch to working prototype in just 20 months. Twenty months!!! The world is a different place now.
FTA: “NASA in June launched a competition for U.S. companies to design and build a full-scale demonstrator. The rules require entrants to target planes around the size of a Boeing Co. 737 that can carry 150 passengers. The agency wants a prototype that could fly as early as 2027 and be ready for mass production in the next decade.”
How does that fit in NASA’s mission?
Also FTA: “Entrants to the NASA competition had to demonstrate their designs can be mass-produced at 60 planes a month”
That’s serious. For reference, there are about 11,000 Boeing 737s, produced over about 55 years. That’s about 200/year or 17/month on average. Reading http://www.b737.org.uk/production.htm claims
“The production rate has increased from 31 aircraft a month in 2005 to 42/month in 2014 and reached 57 aircraft a month by 2019 for the 737MAX.”
That first A there in NASA stands for Aeronautics. Advancing aircraft design and technology is part of NASA's mission. It's even in their official mission statement:
> NASA explores the unknown in air and space, innovates for the benefit of humanity, and inspires the world through discovery.
China actually did propose a train running through Siberia and Alaska to connect the whole world. It would be mighty impractical to ride from New York to London the "wrong" way, though.
The article didn't mention anything about Transatlantic or overseas flights and neither did I. Short, regional flights are the worst offenders for emissions, and that's what trains and high-speed trains would address.
Maybe someone here knows, but I'm always skeptical of any such news where there's not a single numerical figure in the story about the cost or operating difference. What is even the order of magnitude of fuel or operating cost improvement envisioned from these new designs? 10%? 30%
Similarly when any story is written about biofuels for example ("airline <x> demonstrates passenger flight using biofuels"), but the article doesn't quote a single dollar figure on the cost per gallon, you know it's just another story that comes and goes every year, but no significant new progress has been made towards actual sustainable/scaled possibilities.
> Finally, in the 50's, Boeing ushered in the Jet Age with the Boeing 707, which could cross the Atlantic ocean at nearly 1,000 kph.
> I submit to you that the last thing that Boeing engineer would expect to see in 2014 is what actually happened. Here is today's most advanced passenger aircraft, the Boeing 787.
> Unless you are an airplane nerd, you would be hard pressed to distinguish the 787 from its grandfather. And in fact, this revolutionary new plane flies slower than the 707.
I recommend this video from the channel Wendover Production (a lot of stuff related to transportation and supply vhain), which explains what is actually the plane of tomorrow (or rather the plane of 2050):
Spoilers: It's essentially the same as today. As in, the exact same model. Maybe even the same plane that you flew in already if it's a recent release like the 737 Max.
Before that video I had never thought about the age of the plane I am in, but turns out a lot of the planes I flew in were older than I am.
Always cool to see new designs, but I’m skeptical any of this becomes reality.
I’d always assumed the lack of innovation in aircraft design had to do with safety. A long tube that’s not too wide makes for easy egress of passengers in an emergency. A blended wing design does not. I would imagine it very difficult to get something like that past the FAA unless there is some exotic form of emergency escape that’s part of it.
> But a new jetliner design will likely face one of the same challenges seen in the nascent air-taxi business: convincing people to fly on something unfamiliar.
How much innovation is kneecapped out of the gate because of human behavior that cuts it down like a scythe?
Idea: How about a blended wing aircraft - that never has to land?
Fuel, Passengers, luggage and waste arrive via shuttles from the airport, while the plane circles slowly, docking in flight?
Other passenger and personal on end of shift. Leave the same way, to other shuttle craft and the plane flies ever onward.
Only reason to ever land is maintenance which can not be performed mid flight.
In theory, a specialized shuttle might even switch an engine mid-flight if its constructed for it.
For the landings that are unavoidable other special shuttle-craft attach and bring along wheels or flotation packages.
Emergency landings?
Just go with a set of parachutes, after arresting momentum. Or with flotation devices.
The resulting craft would be lighter, more economic, the downtime by its very nature would be lower.
Airports would not have to be rebuild, except for the spoke which harbors the albatrosses.
It might be lighter but how would it be more economical? You'd need a fleet of transport craft just to constantly dock and undock from it and at that point you might as well just make the one plane be able to land.
This has been tried over and over without commercial success. Ground effect vehicles were supposed to replace intermodal cargo container ships too. It ain't gonna happen this time either.
Boeing has proven that you don't need a radical plane design to have it fail. So probably the same people that were held accountable with the 737 Max killing 346 people.
Who will be held accountable if it turns out to be safer and it is the traditional designs that are actually killing people. Too often we fixate on blocking new tech in the name of safety. If a new design does turn out to be safer (which is almost always the case) why don't we consider the lives that could have been saved?
As a concrete example, how many lives were lost because we took many months to approve the Covid vaccine? Who's accountable for those deaths and for showing it could not have safely been done sooner?
paywalled, unfortunately, but just based on the headline and image, this is probably "flying cars" levels of speculation? No commercial manufacturer builds a completely new airplane and brings it to airline-industry-market in under 15 years. Especially designs that have been around for many decades already and aren't being used because economic sense is the only sense that drives the airline industry.
Airframes equipped to use LH2 will, wherever deployed, lock out competitors without, because the lower takeoff fuel weight allows for more paying cargo instead, and because hydrogen electrolysed right there at the airport should be cheaper per joule than petroleum mined, transported, refined, and transported again.
But inboard LH2 tanks seem to present a safety hazard, wings have not enough room. That seems to leave underslung nacelles. None of the concept designs illustrated have them.
