Ask someone to picture an airplane and they’re likely to think of what is essentially a tube with wings and a stabilizing tail tacked onto one end of said tube. Yet it is also no secret that the lift produced by such a tube is rather poor, even if they’re straightforward for loading cargo (static and self-loading) into them and for deciding where to put in windows. Over the decades a number of alternative airplane designs have been developed, with some of them also ending up being produced. Here most people are probably quite familiar with the US Air Force’s B-2 Spirit bomber and its characteristic flying wing design, while blended wing body (BWB) maintains a somewhat distinctive fuselage, as with for example the B-1 Lancer.
Outside of military airplanes BWBs are a pretty rare sight. Within the world of passenger airplanes the tube-with-wings pattern that the first ever passenger airplanes adopted has persisted with the newest designs, making it often tricky to distinguish one airplane from another. This could soon change, however, with a strong interest within the industry for passenger-oriented BWBs. The reason for this are the significant boosts in efficiency, quieter performance and more internal (useful) volume, which makes airline operators very happy, but which may also benefit passengers.
With that said, how close are we truly to the first BWB passenger airplane delivery to an airline?
Heavier Than Air Aerodynamics
When regarding the first ever airplanes to make a successful powered flight, in particular the Wright Flyer, it’s notable where the focus was put in the design. The Wright Flyer doesn’t have much of a fuselage, but is mostly wing, along with some means for control by changing the shape of the wings (wing warping) in addition to the dual elevators and rudders. As an early attempt at controlled (powered) flight, it rather mimicked the way that birds control their flight by changing the shape of their wings.
As airplane designs evolved and saw explosive growth throughout World War I with practically weekly new designs, we saw the appearance of the now familiar design with a distinct fuselage and control scheme including wing-mounted ailerons and similar methods. Bi- and tri-planes gave way to monoplanes, and especially for passenger jets the tube fuselage ended up being extremely useful as a way to add more internal capacity by lengthening said tube or widen it (so-called wide-body jets).
Despite experiments with early BWBs such as the 1924 Westland Dreadnought prototype, 1938’s Miles M.30, 1944’s McDonnell XP-67 interceptor and Canadian Burnelli CBY-3, only these last two saw significant usage, albeit with the XP-67 failing US Army trials. The single CBY-3 airplane that was built did see significant use as a commercial airliner until its retirement in 1964 after which it was restored and moved into the collection of the New England Air Museum in Windsor Locks, Connecticut.
With seemingly an endless string of failures and one quite unremarkable non-military airplane resulting from BWB research by the 1960s, one might be excused for thinking that the BWB advantages are mostly hot air. Here the designs that began to appear by the 1970s began to turn heads, however.
Trade-offs
The advantages of blending the wings into the body are obvious: it first of all reduces the wetting surface (i.e. the wetting aspect ratio), meaning that there’s less of the airplane’s structure interacting with the atmosphere and thus less drag. Second, it makes it possible to turn more or all of the fuselage into part of the airfoil, and thus have it too generate lift. The disadvantages mostly lie in that it makes controlling the airplane more complex as you abandon the inherent aerodynamic stability of a tube. The more extreme examples of this issue are found in both flying wings and lifting body design.
A flying wing design such as the Northrop B-2 Spirit bomber is a purely fly-by-wire design, as only the lightning-fast reflexes of a computerized system can keep what is ultimately an inherently unstable aerodynamic shape stable. This is an approach which was pioneered for a large part in the Lockheed F-117 airplane, which got referred to in such loving terms as for example ‘the flying brick’ due to its rather poor aerodynamic properties.
The move from a tube to a blended wing design can be likened to creating arrows that abandon the cylindrical shape for a blended fletching design: you lose the natural stability (and radar cross-section) that comes with a cylinder-with-fletching. This is of course great if you are designing an agile jet fighter that has to pull off dramatic course changes, or a long-distance (stealth) bomber, but less great if you’re designing a passenger airplane. In a naturally risk-averse industry like commercial aviation, this has kept airplane designs roughly as exciting and innovative as when the Boeing 737 first rolled off the production line, with mostly incremental tweaks and improvements, including to the engines.
End Of The Road
Within the limitations of the tube-with-wings design incredible feats of optimizations have been performed over the decades, with each successive generation being a bit more efficient and their engines more quiet and easier on fuel consumption. New gains within these same limitations are however becoming increasingly harder and more expensive, while a commercial BWB jet liner could see multi-digit percentage fuel savings, increase space for cargo and passengers, while reducing the noise produced by the engines. All with just the first generation of such passenger airplanes.
Most of the fuel savings come simply from the reduced wetting area, and a boost to the airfoil ratio. Together with the ability to move the position of the engines and other tweaks, there is nothing about a passenger BWB airplane that’s truly groundbreaking or revolutionary. The main challenge will be to create an airplane that will both please organizations like the FAA and its international equivalents, and appeal to passengers. Here we have a number of startups and incumbents vying for the limelight, including Nautilus with its Horizon airplane, JetZero and Airbus, as well as NASA research projects like the N3-X BWB.
Of these efforts, the Airbus MAVERIC BWB is a scale model UAV that Airbus used to test and validate the basic BWB design, until 2020 to help design its next-generation airplanes. The Nautilus Horizon is roughly at this level too, with the 2016-founded company working towards building a first full-scale prototype. Meanwhile JetZero got picked by the US Air Force to work on BWB designs for cargo and in-air refueling tankers, which has them cooperating with Northrop Grumman on a full-scale model to demonstrate that is the direction that the US Air Force would want to move into.
Suffice it to say that tapping into the US defense budget is not a bad way to finance a startup, with the know-how and experiences translating into commercial cargo and passenger BWB airplanes. Currently the JetZero Pathfinder 1:8 scale model is test flying at Edwards Air Force Base, with JetZero hoping to have a passenger airplane in service by 2030.
New Skies
Passenger BWB airplanes would be both something very new and exciting, but also very old-school. In a way it would see the commercial aviation market hesitantly abandon the designs that it has been perfecting roughly since Douglas DC-3 propeller airplanes roamed the skies in the 1930s. From new construction methods, new materials, jet engines instead of propellers, to big boosts in efficiency and automation, today’s commercial aviation is both alien and very familiar to that of the 1930s and 1950s.
Even as military airplanes began to morph into new shapes and experiment with pushing every single envelope they could find, commercial aviation became more concerned with not spending money while being dragged by regulators into an era of increased safety and efficiency even as leg space and carry-on luggage size decreased. Now it would seem that, perhaps ironically, the only way forward for commercial aviation is to look at designs that have long since been adopted by air forces.
While for cargo variants of commercial BWB airplanes the question of seating arrangements and windows aren’t very relevant, perhaps the biggest fight will be over how to partition up the much larger inner volume for self-loading freight (i.e. passengers), as SLF is rather partial to having access to a window, an aisle, as much leg space as possible and other such critter comforts. In this 2020 article about the Airbus MAVERIC scale model some sci-fi renders of potential interiors are shown, but as the first BWB passenger airplanes get shown off by the airlines that ordered them, there will surely be very strong opinions by the peanut gallery about whether flying tubes or BWB airplanes are ‘better’.
One thing is certain, however, with the current crisis enveloping Boeing and their lagging behind on fulfilling new airplane orders, if there ever was a decade ripe for big shifts in commercial aviation, this one might just be it. For now all we can do is strap ourselves in and see where things will be in six years or so from now.
Featured image: Rendering of a JetZero blended wing body aircraft with US Air Force markings. (Credit: US Air Force)
They will probably cram them just as tightly.
So now, if the person on the outside edge gets up for some reason they won’t be climbing over 2 people but more like 15-20 people.
Also, nobody is getting out of an enclosed area with so many strangers in it without catching at least a cold if not a flu or covid.
I love flight, as in small recreational planes and/or sky diving.
Flying for travel though… trains just keep looking better and better.
Sure they will, as long as people are willing to trade space for cheaper tickets. But given these designs, I could see cargo/fuel stuck in the center, with passengers in two rows + two decks to the side. honestly might be preferable to have just 100 people per zone rather than 400 in a single big tube
Fuel goes in the wings because that’s where the lift is, and because wings aren’t tall enough to accommodate a walking passenger.
I see you haven’t been taking cheap flights, they will keep cramming past the point of safety and discomfort unless actively forbidden by regulation (and actually do already in some SEA airlines}. Travel is done mostly for necessity, making it inelastic enough that market choice has next to nothing to do with the actions of the company. Also they would rather go out of business than treat customers better.
“I love flight, as in small recreational planes and/or sky diving.”
“That’s not flying, that’s falling with style!”
-Toy Story
They would, if they could somehow invent lighter passengers. But with the current Homo Sapiens, and with a trend of increasing, rather than decreasing body mass, there are only so many passengers you can pack in there. In current designs that’s not a problem, because you have more lift than space, but those new designs give you more space with the same lift, so you may as well get more leg room.
Hmm, you’d guess that the airline industry would invest into the weight-loss industry. I wonder if they’ve done much of that?
No, they just charge for multiple seats, this is already standard practice.
A relief tube with every seat?
I remember how much it cost to fly in the 80’s, time value adjusted it was a lot more expensive than now. That being the case, service is worse (not the fault of the workers), amenities are worse, outcomes are a little better, seats are crowded closer. Frankly I don’t mind paying a little more for extra space, and I wish I could always pay for the extra bag up front, which most airlines are figuring out. The antics my mother willingly jumps through so as not to have to pay to check a bag are ridiculous however.
I don’t check my bag for other reasons. Key among them just knowing where my bag is. But mostly just so I can walk off the plane and head for the exits.
How are outcomes “better”? Injuries have been rare since the FAA took over actually went up a bit when partial deregulation was pushed, but the majority of crashes are directly due to maintenance rather than pilot error, and that has NOT been getting better. Airlines will do anything to avoid paying for maintenance legally, and sometimes illegally.
Wide body jets moved from one aisle to two to deal with this issue. I could see adding aisles every 4 seats or so just to keep up with loading/unloading times and make drink/meal service possible.
They go up to 6 seats together to maintain the “rule” that no one has to pass more than 2 other seated passengers.
It will need to take less than 90 seconds to evacuate the entire aircraft using 50pct of its exits, without any climbing, that’s a certification requirement.
i’m not clear on how immutable the instability is? is it a consequence of just nowhere good to put the tail? obviously we’re heading towards a world with high-reliability automated systems (i.e., it crashes in the case of any control problem, but they are suitably rare). but in the meantime i’m imagining a blended wing with tailfeathers on a pylon? for the kind of passive stability that provides some redundancy. just spitballing here in ignorance..i’m sure there’s a reason this hasn’t been done (though the B-1 is kind of like that)
I think the instability is because of their design assumptions, not because of the BWB itself. Barnaby Wainfan made a homebuilt aircraft that looks a lot like the F117, called the Facetmobile, with a blended wing, and many people have made Dyke Deltas, which are also BW homebuilts. They fly fine with low-time pilots and no electronics at all. (Wainfan’s airplane at one point had no electrical system: pull-start engine with magneto ignition.)
If you’re designing something that flies at Mach 0.88 with absolutely minimum drag, that means some design features around the control system that makes control difficult, but that’s not really the fault of the blended wing design.
If you are intersted in Facemobile you must read is NASA-report:
https://wainfan.co/media/pavreport.pdf
Remember the Facetmobile FMX-4 was designed before F117 was known.
It is perfectly possible to make a flying wing stable. You “just” need to put the centre of mass forward of the neutral point of the plane as a whole. However, there are advantages in making a flying wing unstable in pitch. In the case of fighter planes the relaxed stability leads to higher agility, but in the case of large flying wings it means that control deflections can be much smaller, and once the plane is trimmed for cruise it will have a much better lift to drag ratio, and therefore less fuel consumption. For the stealthy bombers the smaller control surface deflections also mean less disruption of the wing surface, reducing the radar cross section.
It’s a flying wing design with all the problems and benefits. Will take up more room at the airports, and have ground handling issues in congested spaces. New concept, will have issues convincing J.Q.Public it’s safe as a tube
Turns will be barf-tastic for people out and away from the centerline. Doubly so when you’re scrolling Instagram. And as for windows, lately when I fly, people close them and stare at screens anyway, and I feel like the dick for letting in all that bright light so I can sight-see. So perhaps windows are way less important now, and it would be fine to put people in the middle, gas down below, and cargo on the sides. Or not?
You’re not “the dick”, that’s why the windows exist!
agreed
They should mount a wifi accessible camera underneath the plane so people can sightsee from a screen and record it even, without the spots on the window.
I was on a flight on South African Airlines years ago where one of the entertainment channels was a camera on the belly somewhere looking forward and down.
Sadly, they turned it off with the rest of the entertainment system when we started our approach
An airline in the USA had a nose mounted camera for passenger viewing. They shut them off after a crash and the victims’ families sued for the additional grief their relatives may have had watching the plane auger in.
pff. they probably didn’t buy Joo Janta 200 peril sensitive sunglasses.
I flew on an A350 a while back that had both a nose wheel camera and a tail camera option on the inflight screens. It was cool seeing the view from up on the tail while moving around the airport.
Barf-tastic, indeed. I’d imagine banking maneuvers would feel like sitting sideways on a seesaw.
“making it often tricky to distinguish one airplane from another.”
If it’s a smoking hole in the ground [insert joke here]!
B^)
Passengers are rather fond of being able to keep breathing at altitude. A circular cross-section tube is easy to pressurize without structural reinforcement. Even the oddball 747 is just two circular cross-sections with a tension member floor forming the common chord.
How do you pressurize these non-circular shapes without requiring either additional structural mass or a second (circular) pressure hull?
By depending on the strength of carbon fibre, I presume. Also, inner reinforcing members.
Another advantage of tube fuselages is manufacturability, especially with the industrial base already being developed around it. Boeing does their CFRP tube in short sections, while Airbus does theirs in lengthwise quarters. Both have to then join them, which is where all the difficulty lies (though process management on the CFRP layup sure isn’t nothing). Even people with a vested interest in more CFRP layup say that, most likely, the next tube-body designs will go back to aluminum fuselages with CFRP wings.
Now, for blended wings, the advantages of CFRP are enormous, as you need some way to manufacture those compound curves, and thats an inherent part of carbon layup tooling, whereas forming aluminum is a much more complicated process than laying sheet on a tube and riveting it (yes, I know I’m being reductive). This is why Boeing switched the wings to CFRP on the 777X.
One of the issues, though, will be scaling the industrial base, as only a couple of companies have actual experience in making carbon layup machines at scale. That’s if the manufacturers decide to actually go blended wings. Airport infrastructure is all built around tubes, which may be a consideration that overrides whatever efficiency gains a blended wings might offer.
It seems like it’s the “everything else” that keeps any of these more blank slate approaches to jet airliners from going anywhere.
It’s the same bullshit they have been shoveling for 30 years, just with a different worthless hack blogger’s name on it.
People (like the OP) cite the importance of passenger preference as established fact, but that’s far from obvious. Airlines don’t necessarily even tell you what equipment you’ll be flying on, much less give you a choice. If they did, there’d be a whole lot of new 737 MAX 9s in scrapyards.
So when change is slow and incremental, airlines can get away with making the passenger experience steadily worse. This is surely part of why they’ve opposed any substantial change in aircraft design for nearly a century. Because the first carrier to fly a truly novel design /would/ have to offer something to passengers, and not just shareholders.
Like, it might not be enough to save 10% on operating costs, if you have to offer passengers 20% more space to lure them on board. I would guess that to reach the next local minimum, you’d need to go to a super-wide cabin with the same number of seats, but forget about windows entirely, so that the envelope can be designed for efficiency alone.
I always see which plane I’ll be flying on while booking (and flew on a max yesterday!). I just don’t think that people are actually worried enough to start taking less convenient or more expensive flights to avoid the max.
It wasn’t until he was in the air that aircraft engineer Theodore Honey realised he was flying on a Rutland Reindeer.
The type of aircraft is printed on the safety sheet in the pocket of the seat back in front of you. You, know, the sheet the fight attendant refers you to during the safety briefing?
I also think the 737 Max has undergone a slight name change recently to obscure the 737 Max legacy.
Well, you have to buy a ticket before you see the safety card. For the bigger carriers you can probably tell from the seating chart before you pay. But if you want to fly to a given place, at best, you can choose between a Boeing plane or its Airbus equivalent, if you compromise on price or times. And you don’t have any choice about the interior as fleets are gradually refreshed.
I mean, I’m not sure it could work differently. I’m just not convinced by this idea that passenger wishes constrain design.
A counterexample would be something like the higher cabin pressure on the 787, but were carriers pushing for that, or did Boeing engineers happen to get away with taking pride in their work because it was an all-new design?
Except that anybody that really wants to can look online and see what planes are being flown for which trips, it’s all out there for anyone to find, other than the last minute, occasional change.
In the past at least 15 years I’ve flown a little over a dozen times, and I’ve known exactly what plane in which configuration it was going to have before I even bought the ticket.
It seems like it’s the “everything else” that keeps these more radical approaches to jet airliners from going anywhere. How do they interface with airport infrastructure that’s meant for traditional airliners? How do you work on the engines? How do you get people off in an emergency?
Am I the only one who looked at the Airbus MAVERIC model and thought “cute cartoon manta ray”?
I was under the impression that modular designs saved a lot of cost. That doors are the same front to back. These wings look like a step back, every square inch is unique.
They’ve been talking about doing this since at least the sixties or seventies. I remember some of the commercial passenger concepts back then. I don’t buy it, especially without any currently-competent manufacturers on board (MAYBE Airbus, but if you think current-day Boeing could build a radical new design right now without it being a total screaming bloody disaster on the international news, you’re delusional).
I’ll believe it when I see it, considering that this has been bandied about one way or another for half a century and more. Could be another half a century yet.
And in 10 years they’ll be powered by fusion reactors!
whoah, why am I hearing about the CBY-3 Loadmaster now?
https://www.airhistory.net/photos/0402607.jpg
https://duckduckgo.com/?q=cby+loadmaster&ia=images&iax=images
Seriously, other than the folks who are actively concerned with improving the way we drop bombs on each other, no one else has the time, money, or resources to build something revolutionary that will be accepted by the air carriers, the regulators and the public.
Boeing is hanging on by a thread and can barely deliver reliable planes that are based on 20 year old technologies. I’m pretty sure Airbus has their own problems.
OTOH Lockheed Martin has a drawer full of signed checks for pretty much like 1% of all US tax dollars. (Can’t be bothered to check but it’s HUGE).
So, better bombers for everyone!
“So, better bombers for everyone!”
“This is your pilot speaking; we will soon be over the target, urr airport, please have your seat belts fastened securely, and have a good hold on any personal items you brought on board.
We will begin bombi… deplaning in 3 minutes! And thank you for flying with us today!”
Just think of how much more profit could be made if airlines could just “drop” passengers off (without stopping) at way points along longer routes. The Jetsons had this figured out decades ago. Now they’ll just have to figure out how to pick up passengers along the way without stopping.
You’ll need a way to emplane. Enter the skyhook: https://en.m.wikipedia.org/wiki/Fulton_surface-to-air_recovery_system
I always preferred “the Hopeless Diamond.”
Rumor was the original pilots called it “The Wobbling Goblin”.
Yup, couple actually got sea sick/motion sick, as I have been told by people who knew
While aerodynamically the BWB is an improvement over the “tube with wings” in so many other aspects it’s a downgrade that it’s basically a non starter. On Tube with wings aircraft the engines are easily accessible and serviceable under the wings, loading and unloading passengers, cargo and luggage is easy and emergency egress is possible through a multitude of locations, the wings provide a massive amount of fuel storage away from passengers and the air frame can be made aerodynamically stable. In a BWB the aircraft basically can’t be aerodynamically stable, engines are usually difficult to access and inspect, loading it tricky and emergency egress is often only possible towards the front of the aircraft. Loading passengers quickly and efficiently is also difficult (they’ve tried a multitude of different passenger cabin layouts and they basically all suck in terms of a normal quick turnaround compared to a tube and all but the most space inefficient designs are downright dangerous in case of an emergency egress scenario. Manufacturability of of BWB is also terrible.
In general, the downsides of a BWB in basically every aspect apart from aerodynamics far outweighs the small improvement in aerodynamic efficiency.
This trend is happening/has happened with bicycles at a much smaller scale. Metal tubes are easy to make and shape. Once you introduce carbon fiber, you’re no longer restricted to tubes. As the cost of composites go down, you see more of it used.
Some of the same factors are driving the change in aviation. Cost is not that much of a factor for racing bikes or military planes. As the cost comes down, there will be more and more wacky shapes in civilian aviation and lower end, non-racing bikes.
yes! this is the perfect example for how manufacturing of “every square inch is unique” continues to evolve. the tubes on a bike were all uniform. then they were different sizes from eachother. then they were double-butted (non-uniform thickness within a single tube). then they were ‘hydroformed aluminum’ or something, where every inch of every tube in the bike was unique…no straight lines anywhere. and all these things steadily progressed from ‘elite’ to ‘bargain basement’. to where now the $200 ‘racing bike’ on temu is clearly “hydroformed aluminum”.
(i’ve watched all of this happen with dismay…the height of chromoly steel tubes circa roughly 1990 is the only thing i want)
some of the problems i think will be hard to solve but “it is hard to build today” hasn’t been true for some time, and will be even less true in the future.
Long overdue. Looking forward to it
With advances in materials and manufacturing the only thing holding back production of blended wing airliners now is inertia.
Superior operating economics will eventually cause industry wide adoption.
Major issue with seats situated far from the roll axis: perceived forces on passengers during commanded rolls which will have to be more gentle than usual and, worse, turbulence where they can’t be so well controlled. I read about that in a critique of these kinds of fuselages.
Developing an aircraft from the scratch is estimated to cost $50 billion (according to Boeing). No sane company will spend this much to create a “cool” airplane that is revolutionary. Look at the A380 that nearly bankrupted Airbus. Addirionally, the profit margin on aircrafts is very low.
A blended wing is fine for military aircraft holding two or three crew members in a centerline pressure shell, but it would be impossibly difficult to pressurize all of the space in such a shape. Tube shaped bodies are shaped to allow pressurization by converting pressure differences into skin tension. The blended wing is a fine platform for carrying fuel or freight (or bombs) which don’t need pressurization – but not people.
Like so many advancements in the world of science (better batteries, new medical treatments and many other things) there are plenty of people who claim to have a “better” airplane design. But until its actually something I can use (in this case, book a ticket on) its meaningless in the real world.
I read about so many advancements here and elsewhere and those advancements never go anywhere.
Combine all this with vectored thrust, and now you really have something. The Engines stick out of the top of the aircraft. Why not make the engines gimblable. The engines can tilt up / down and side / side. This can replace the tail. This would be like vectored thrust without the vector plates. You just tilt the entire engine nacelles.
Works while the engines run, not so much if they fail
For overland journeys, I already prefer a sleeper train over the invasive hassles of dealing with airports. If we can get the cost per kilogram low enough, I’d love to see a modern Zeppelin for intercontinental travel. I’d be happy with a taking a day or two from the USA to Europe, if there was room to walk around, look out the windows, have a decent sleep and meal.
Another neat aspect of these: liquid hydrogen has excellent energy-per-mass, but bad energy-per-space. Blended wings have more internal space at the same lift, synergizing with the only reasonable (imo) zero-carbon aircraft power storage.
as long as it’s not a Bow-Wing.
Knew some guys that worked there many years back. The quality has been declining for long before it became a publicly known issue.
Just cuz it says “cheap cheap” doesn’t mean it’ll fly.
Im just going to say this and say loudly just like single crew commercial aircraft this blended wing foolishness IS NOT GOING TO HAPPEN !
once again ITS NOT GOING TO HAPPEN (Anytime Soon)
How are you going to build airport infrastructure around this? You do know those wings will be unusually long in a blended wing .
How will you get the engine configuration right ? You do know engines are podded for a reason ITS CALLED EASE OF MAINTENANCE!
How are you going to change FAA regulations for evacuations without throwing the whole book out ? lol explain this
This is not going to happen anytime soon I guarantee it , conventional aircraft design especially in commercial has been consistent for the last 65 years for a reason
Podded engined cylindrical aircraft are seen more ergonomically efficient to use .