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".
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.
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. :-)
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 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..."
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
Maybe just put a bunch of cameras all over the exterior so the passengers can see what’s going on wherever they are sitting.
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.
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.
(Source: I have an aerospace engineering degree from Embry-Riddle)
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.
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.
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.
https://www.technologyreview.com/2013/01/24/180345/hybrid-wi...
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.
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.
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.
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.
> 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.
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.
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."
https://www.amazon.com/747-Jumbo-Revolution-Christopher-Spen...
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.
In the past, concepts for a transatlantic tunnel that is used by advanced trains were conceived:
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.
https://idlewords.com/talks/web_design_first_100_years.htm
> 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.
https://m.youtube.com/watch?v=ql0Op1VcELw
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.
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.
Highly recommended Mustard video (their videos have great production quality) why one wing design didn't take off https://www.youtube.com/watch?v=dByvPIyIbZE
How much innovation is kneecapped out of the gate because of human behavior that cuts it down like a scythe?
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.
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?
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.
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.
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.)
I think you're thinking of pure flying wings.
* https://en.wikipedia.org/wiki/Marske_Pioneer
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.
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
This is why old planes long since retired from passenger service are now used for cargo flights, which have an 8x higher accident rate. https://www.npr.org/templates/story/story.php?storyId=212692...
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]
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.
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.
There are risks to create a "vomit comet". Think about cleaning bills.
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?
> 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.
[0] https://www.sciencedirect.com/science/article/pii/S037604212...
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.
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.
See also SAS flight 751, where ice broke off from the wings and were ingested into the engines https://en.wikipedia.org/wiki/Scandinavian_Airlines_System_F...
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?
But maintenance becomes a bitch, so they put'em back under the wings eventually.
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 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.
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.
https://news.schiphol.com/why-do-the-window-blinds-have-to-b...
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 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.
After the first few times - especially if you're flying the same routes over and over - I got used to it, for better or worse.
It... might have something to do with a psychedelic experience I had on a plane once...
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.
That said there is a fair about of wiggle room so I doubt it’s a significant issue in practice.
At least it's never happened to me, but I am only a passenger.
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 ground is whatever you accelerate towards.
https://www.boldmethod.com/learn-to-fly/aerodynamics/the-aer...
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:
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.
I even have a cool name word to describe it: "lid"!
But even beyond that feeling like you’re falling out of your seat is unpleasant.
As to why no cup holders, people aren’t going to use them most of the time and they don’t even help that much in turbulence.
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...
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.
But on the other hand, I've never experienced turbulence that's made me more than barely uncomfortable in any plane.
closest modern aircraft to it is the 717/MD90, which Delta is still flying, but not for much longer iirc
You do sometimes see cup holders on private airplanes, but in commercial aviation the efficient solution is to avoid needing them.
Similarly, adding decent cupholders to airplanes is not going to reduce passenger space.