46 ms·
Flying-V: Flying long distances energy-efficiently
- duxup 7y agoSo when I'm in a window seat on a traditional aircraft I see the wings flex a great deal even on a normal flight. Are people going to be bouncing up and down all the time?
- giarc 7y agoI remember watching a documentary a long time ago and they said that this design (or one similar) had the draw back that people would feel the turns much more since they would be further from the centre.
- skykooler 7y agoThese wings will necessarily be much more rigid, as they are far thicker than traditional wings and pressurized. One thing not mentioned here is that that flexible wings act as a suspension system for an airliner; I'd expect that in a Flying-V you'd feel more turbulence.
- asdfadsfgfdda 7y agoThe wings will be more rigid (and will have lower bending loading because the payload is more evenly distributed along the wing span), but any roll rate will cause the passengers to experience an acceleration. Maneuvering flight will not be pleasant for the passengers.
- gmueckl 7y agoHave you never noticed the airframe itself flexing? When I look down the aisle from a back row seat on a turbulent flight I can see some pretty big oscillations in the fuselage. Still, it is not uncomfortable, mostly because the frequency is pretty low.
- leeoniya 7y agothat looks like a deicing SNAFU just waiting to happen. that's a lot of surface area that has to be de-iced to ensure nothing breaks off and enters the engines at the back.
- GuB-42 7y agoThe biggest issue with true flying wing aircraft is that they are aerodynamically unstable. They can't be flown by humans, and I don't know how well they do in unusual configuration, things like stalls, spins, spiral dives, ... The rules are different for commercial aviation and for the military. The goal of commercial aviation is to get people to their destination, as safely and cheaply as possible, you don't have to fight against an enemy. As a result, commercial aviation is not very creative. They tend to use proven designs and incremental improvement. Making a civilian flying wing aircraft will be a certification nightmare, which may involve several full-scale prototypes, a new kind of training for pilots, etc... It is a world where there is still a switch for the "no smoking" sign in the cockpit that doesn't do anything because all flights are non smoking now. Removing the button would require re-qualification and it is easier to leave it there. The B737-MAX fiasco is another illustration. Just look at how far their went just to limit change... I'm not saying that a flying wing commercial aircraft can't be done, but I have a feeling that the placement of passengers won't be the biggest issue.
- wereHamster 7y ago> […] flying wing aircraft […] are aerodynamically unstable. They can't be flown by humans […] RC flying wings are regularly flown by humans without any software in between the input and control surfaces.
- sithadmin 7y agoReally now? As you might imagine, the scale and operating requirements of _actual_ aircraft introduces complex engineering challenges that aren't present in toys.
- Zak 7y agoThere are very specific regulations relating to how transport category aircraft have to behave. One of these is the reason the 737 MAX has the specific MCAS behaviors that are probably responsible for two crashes: causing the aircraft to stall must require continually increasing the pitch-up control input (or something substantially similar), and that wasn't the case at low speed, high thrust, and high angle of attack. It may be difficult to achieve the required flight characteristics without software augmentation in a flying wing, even if RC hobbyists can usually fly them manually without crashing. The 737 MAX has raised the question of whether it's a good idea to approve transport category aircraft that require help from software to have acceptable flight characteristics.
- nine_k 7y agoMy friends' immediate reaction: "Good luck trying to certify this". I wonder how bad the odds would be even if an aircraft like this showed perfect flight safety characteristics (which is not a given).
- deleted 7y ago[deleted]
- mattlondon 7y agoMore details here: https://www.tudelft.nl/en/ae/flying-v/ https://www.tudelft.nl/en/ae/flying-v/ > "we’re looking into new options to having a rest or taking meals on a plane. Offering food from a buffet is one of the options we’re sinking our teeth in" Based on the A380 "promises" of in-flight gyms/casino/salons/creches, I think we can safely call bullshit on this - we'll just get more seats crammed in as usual (in economy at least - perhaps first class will get these?). That is fine - I understand the economics - it is marketing I guess.
- __m 7y agoYou don’t have gyms/casino/salons/creches in your A380?
- kens 7y agoIn case anyone else wondered why an A380 would include religious symbolism: in North American English, a crèche is a Christmas nativity scene with baby Jesus, while in British English, a crèche is a nursery/daycare. The latter makes much more sense on a plane.
- mattlondon 7y agoInteresting - I assumed creche was an American term and widely understood. In the UK I've never heard it used much (we typically use "nursery" but I opted for creche based on the assumption that most readers are not UK-natives)
- sapphire_tomb 7y agoI'm from the UK and I hear crèche used way more than nursery.
- zupzupper 7y agoNursery is way more common here in the States, creche is usually used when someone is writing sci-fi or fantasy and wants to sound fancy =)
- challenger22 7y agoWow. The criticisms I've seen about using flying-wing designs for passenger aircraft (planes that look like the B-2 bomber), are often focused on how bad the boarding process is for the movie theater seating they require. This design looks like it eliminates the seating problem pretty well. Flying wings have been known to be more efficient for a long time; logistics problems are the devil in the details.
- satellitec4t 7y agoI thought the problem was they are more difficult to fly, less stable.
- mcguire 7y agoMy understanding is that the YB-35 flying wings had difficulties with stability along the Y axis, part of the reason they weren't suitable as bombers (for dumb bombs).
- zymhan 7y ago> Flying wings have been known to be more efficient for a long time Source needed
- walrus01 7y agoIn the UAV world, the longest endurance loiter time fixed wing craft are either relatively slow and with long, straight wings (the 30 hour version of the rq-9, or the global hawk), or are flying wings...
- zymhan 7y agoSure, but those are not features you want in a cargo or passenger aircraft. The Global Hawk has a wingspan over 50% as long as an A350, yet it weighs 1/10th as much. There is no comparison.
- 7y ago
- lallysingh 7y agoSo how are the dynamics of this thing in the air? Easy to maneuver? As safe?
- tomstockmail 7y agoI'd be interested in how they would manage weight distribution as well. Will the plane still fly in a situation where passengers on one side of the aircraft need to be on the other side?
- zymhan 7y agoColor me skeptical that an idea that has existed for over half a century still isn't feasible. https://aviation.stackexchange.com/questions/65124/how-is-a-flying-v-more-efficient-than-current-fuselage-over-wing-designs https://aviation.stackexchange.com/questions/65124/how-is-a-... https://aviation.stackexchange.com/questions/12782/why-are-there-no-blended-wing-passenger-airplanes-in-operation https://aviation.stackexchange.com/questions/12782/why-are-t... A little more skepticism: > Sadly for the Flying-V, it will probably fail like the blended wing body designs we've seen down the years. It's for the same reason, too: airplanes bank as they turn. That's not much of a problem in a conventional airliner design, where passengers are never that far from the plane's central axis. But as you move further out from that central axis the effect becomes a lot more pronounced. https://arstechnica.com/cars/2019/06/radical-new-airliner-could-save-fuel-but-ride-like-a-roller-coaster/ https://arstechnica.com/cars/2019/06/radical-new-airliner-co... There really is nothing new about a lifting-body design.
- throw0101a 7y agoOne major problem with flying-V is that of stability. However, with fly-by-wire systems, this is helped with computer control. The A320 was the first all-digital plane in 1984, so it was unlikely anything before that could have been developed (and passed FAA/EASA standards).
- mcguire 7y ago...and at it's first public outing, the test pilot dropped it in the trees at the end of the runway. That would have likely killed a new aircraft manufacturer.
- zymhan 7y agoMeanwhile Boeing's mechanical rudder actuator in the 737 caused two verified and possibly many more crashes during passenger-carrying flights.
- jeltz 7y agoWhat about using them for cargo?
- perfunctory 7y agoEvery time I read about increased efficiency I have to think about Jevons paradox https://en.wikipedia.org/wiki/Jevons_paradox https://en.wikipedia.org/wiki/Jevons_paradox
- zymhan 7y agoAgreed, even if you could reduce fuel consumption by that much, the result should be lower fares, inducing more people to travel by air.
- Nursie 7y agoSurely at some point demand is effectively satisfied?
- Tade0 7y agoI think the market for air-commuters is far from saturated. Then again there are only so many planes that can land on a given airport in the course of one day.
- mgbmtl 7y agoUnpopular opinion, but we could tax fuel at a higher rate than we do now (or stop subsidizing pollution, depending on how you view it).
- averros 7y agoWhy would anyone want to give more tax money to politicos? So that they could kill even more people in pointless wars?
- onychomys 7y agoIf we've learned anything from modern airline capitalism, it's that they'll charge the same price and just pocket the increased profits.
- 7y ago
- sbjustin 7y agoI'm curious what kind of impact a design like this would have on pilots getting checked out in the aircraft.
- jayrot 7y agoIt would be a significant time investment to be checked out in a radically different type like this, but not impossible. It mostly comes down to the systems, avionics, and procedures which can be radically different already, even in similar-looking planes.
- 8draco8 7y agoI also wonder about engine placement. Engines on top will push the nose downwards in case of adding more trust. There is also issue of stalling on ascend. On ascend, wings would very easily obstruct air going into engines, reducing their power. Also currently aft-mounted engines require vertical stabilizer to be above them to counter act the forces generated by the engines. I don't see any vertical stabilizers in this concept.
- goobynight 7y agoThis thing looks sick. I wonder if any savings will make its way to the customer. > Passenger comfort is also taken into account. That could mean just about anything, fwiw.
- SketchySeaBeast 7y agoThey put the lightest, thinnest foam imaginable over the incredibly rigid seats.
- NikolaeVarius 7y ago> Its improved aerodynamic shape and reduced weight will mean it uses 20% less fuel than the Airbus A350, today’s most advanced aircraft. That is such a meaningless claim.
- anarchy8 7y agoWhy? That's a perfectly quantifiable claim.
- mercutio2 7y agoI suspect the commenter is responding to “the world’s most advanced aircraft”, which does seem like a qualitative statement.
- baud147258 7y agoIt doesn't say it's for the same number of passengers, equivalent travel time and distance traveled.
- jsnell 7y agoFuel use is generally measured per distance traveled, so that part is implicit in the claim. The passenger capacity is talked about in the next paragraph: > What’s more, the Flying-V will carry the same number of passengers – 314 in the standard configuration – and the same volume of cargo, 160m3.
- mywacaday 7y agoI wonder what the comfort level would be like in a rough landing being so far left/right of the center of gravity if the plane was doing a lot of rolling corrections?
- aidenn0 7y agoBanked turns are a bigger issue. However, judging by the window placement, the passengers furthest aft are maybe twice as far from the center of rotation compared to a widebody? That's far better than any other flying wing/blended wing concepts I've seen to date. [edit] Also the traditional place for first-class travellers will be no further than in a widebody aircraft, so the people for whom the airlines actually care about comfort will be unaffected.
- russdill 7y agoI'm not seeing a problem with banked turns, only high roll rates. During the turn, so long as it's coordinated, everyone, regardless of position, should have the same experience. It's entering an exiting the turn where you could have some greater effects. But again, so long as you use a slow roll rate, it shouldn't be too noticeable.
- nradov 7y agoThat's the problem. When passengers are seated too far from the axis of rotation they're in for a nausea inducing ride. Designers could reduce the problem to an extent by building a double deck passenger compartment and putting the baggage compartments out toward the wings, rather than the current standard design which places passengers on the upper level and bags on the lower level. But there are limits to how well that can scale. I'm skeptical that we'll ever see flying wing or blended wing body designs used for airliners. Cargo and military applications are probably more realistic.
- Quenty 7y agoThe proposed design puts the cargo on the inside of the V to maximize good views, and probably helps with logistics. I imagine the novelty of looking forward while flying is a selling point.
- Atiim 7y agoHow is this a new concept when blended wing body (BWB) existed since 1920s [1], with Boeing X-48 being the latest in 2007-2012 [2]? 1. https://en.wikipedia.org/wiki/Blended_wing_body https://en.wikipedia.org/wiki/Blended_wing_body 2. https://en.wikipedia.org/wiki/Boeing_X-48 https://en.wikipedia.org/wiki/Boeing_X-48
- nicktelford 7y agoI think because this is a V-shape, instead of a triangular flying wedge.
- aresant 7y agohttps://www.jbenad.com/flyingv https://www.jbenad.com/flyingv appears to be the original source and PhD candidate behind the design with great info / pictures / etc.
- dmitrygr 7y agoThe main problem with flying wings, and probably this design too, is that they are inherently unstable, and without very precise computer control they are uncontrollable. Compare to modern planes that a good pilot can fly and land with zero computers, given some effort. (They are stable, and with no control inputs at all just keep flying in same attitude as they are currently in) In a flying wing, computer failure is a certain airframe and passenger loss. I don't know any engineers who write flawless code. Do you?
- chroem- 7y ago>flying wings ... are inherently unstable Not if you use an airfoil with an appropriate pitching moment, that's designed for flying wings. Look at all of the hobbyist models that fly just fine using very crude control inputs. >In a flying wing, computer failure is a certain airframe and passenger loss. No.
- ardit33 7y agoYou have never flied a kite have you? What do they most of them look like? Flying wing!
- upofadown 7y agoFlying wings that are controlled entirely manually exist. A favourite example (I know people that have flown these) is the Marske Pioneer[1]. An actual glider with highish aspect ratio wings that was and is quite flyable by hand [1] https://en.wikipedia.org/wiki/Marske_Pioneer https://en.wikipedia.org/wiki/Marske_Pioneer The design in question is more of a flying dart than a flying wing anyway. There is no reason to think it would be particularly unstable in pitch.
- ryder9 7y agoand manufacturing blended wing bodies is very difficult to do
- salamander014 7y agoAre there wing designs that encompass strong dihedral characteristics?
- 7y ago
- shock 7y agoThe article is titled "KLM and TU Delft join forces to make aviation more sustainable".
- feniv 7y agoFrom the title, I thought this would be about an airline flying using the V-formation like geese or military jets to reduce fuel.
- LoSboccacc 7y agoafter some clicking you can see the '2% lighter' claim on a demonstrator, here: https://www.jbenad.com/flyingv https://www.jbenad.com/flyingv which makes me even more dubious about this whole thing; the claim is that this configuration fits in the dimension of the airbus is compared to, so by logic alone the increased surface area should end up in a greater weight, and that's without considering the increased structural elements that are required to avoid flexing and twisting of the two heavy sections to which the rear wings are attached, which have a lot more momentum than your usual wings, since they carry more weight and farther than the center of mass/rotation. I also wonder where would the fuel be stored. needs to be around the center of mass and lift, to avoid the com shifting around as the planes flies. and there aren't wings there conveniently placed near the com to store it, so, is it going to end up below the passengers? that'd be a huge safety hazard.
- Theodores 7y agoFuel is fuel, wherever it goes there is a safety consideration. The last crash I saw on the news had something nasty going on with the engines hitting the tarmac, the above wing placement of the engines is a safety feature as I see it, even though that design choice is more out of consideration for noise - it should be quieter for those living under a flight path. From the evolution of the bicycle to the mountain bike I can remember that a big, thin-walled tube is stronger and lighter than a narrow, thick-walled tube. I know planes are different, but bigger does not automatically mean heavier. You could have all of the fuel at the back, behind the passengers and engines. The flight control surfaces and some thrust vectoring could accommodate that. A U.S company called Boeing know a thing or two about making automatic systems for mitigating against a less than perfect centre of gravity. They went for less than ideally located engines rather than less than ideally located fuel. Allegedly there have been a couple of hiccups with this system but the general idea is that not even the pilots know that there is a computer accounting for changes in centre of lift/gravity, it just works. On Airbus planes it has always been fly by wire. By 2050 - when this V thing is supposed to go into service - the idea that a human should fly a plane will seem daft, if the computer is doing it all anyway then the plane does not have to be dynamically stable or even balanced from side to side. It should be able to precisely balance out the shear forces no matter what the conditions. You could even turn the thing without banking. Tongue in cheek criticisms aside, it is better than my student project and a nice thing for KLM's 100 year celebrations.
- AFascistWorld 7y agoSo what the speed, this doesn't seem like it can fly as fast, which naturally reduces fuel needs.
- a3n 7y agoThe engine placement in the image looks like if one engine has a catastrophic failure it might take out the other engine. Engines have taken out hydraulic control lines in the past.
- phkahler 7y agoIIRC there are rules that any catastrophic engine failure must be contained. The Concord was granted an exception and that didnt go so well. Degree going out the back and hitting hydraulics was the cause of some other incident like Sioux City Iowa.
- nradov 7y agoThe engine placement is also problematic for maintenance. Airlines prefer to buy aircraft that their mechanics can service with just a short ladder. That's one of the main reasons why all recent designs have engines only under the wings.
- sokoloff 7y agoIf it gave them a 1% cost advantage, airlines would be happy to have mechanics on scissor lifts or in buckets.
- baybal2 7y agoThe sole fact that they will only get 20% over A350 in a radically different design tells just how well optimised are the current designs.
- CoffeeDregs 7y agoThis is the umpteenth commercial flying wing we've seen and none every fly. Perhaps this time will be different... MIT also came up with D8 or double bubble (see: https://www.nasa.gov/content/the-double-bubble-d8-0 https://www.nasa.gov/content/the-double-bubble-d8-0) but that, too, was 9 years ago It certainly seems as though we're stuck in a local minima w.r.t. commercial aircraft.
- gmueckl 7y agoMaybe going to full airliner size in the first step is just too big of a delta to take on at once. A flying wing business jet might be an interesting intermediate step (especially interesting for extravagant billionaires who would like to impress in style, I guess).
- CoffeeDregs 7y agoThat's a nifty idea: put all the fuel and luggage out towards the wings and the passengers down the center. No more discomfort for passengers (during turns and turbulence) and you'd still reap the benefits of the BWB design. Though this would block window views...
- Johnny555 7y agoNobody is building this plane (yet), KLM is just funding more research, any commercial airliner based on this technology is likely decades away. The 787 took about a decade to develop and it's based on a more traditional platform.
- riffraff 7y agoso, why is the A350 the most advanced plane? I had not heard this claim before.
- SteveCoast 7y agoIt’s the newest-ish airframe until the carbon 777 flies.
- SteveCoast 7y agoIf the engines are over-wing you know it’s nonsense.
- hawski 7y agoCould you expand why for a layperson?
- tropo 7y agoI wouldn't say nonsense, but the problems are different and maybe worse. Below: Engines can strike the ground. There is more debris ingestion, ranging from sand and burst tires to people and baggage carts. Noise regulations are harder to satisfy. Above: Failure causes nose-up (as power is lost), which may lead to a stall. The aircraft sits lower in the water after a water landing. Being nose-up may put the intakes in slow turbulent air flow, killing performance and possibly stalling the intakes. Ice and rain may come off the body, to be ingested by the engines. Some things could go either way. Maintenance is going to involve a crane or a jack to get the engines off.
- kazinator 7y ago> "integrate the passenger cabin, the cargo hold and the fuel tanks" "Flying Pinto".
- runxel 7y agoIf only Reimar and Walter Horten could see that! Really great to see these advances in aviation.
- justfor1comment 7y agoWhy does it look less aerodynamic than a normal plane? Isn't a rocket or missile like shape the most aerodynamic one? Planes are pretty close to rockets with thin wings for maneuverability. Fling V has so much surface area being pushed against the air, I am honestly surprised at their claim of being 20% more fuel efficient.
- Leherenn 7y agoIn term of pure drag, you're right, you want to reduce the surface and that's not what this design does. However, for aerodynamic efficiency it is the lift/drag ratio that matters. And while in a normal airliner the body provides very minimal lift, here it's basically a wing and thus generates a lot of lift. The end result is that while the drag is probably worse, lift is likely improved enough to compensate. (Also, drag might not be that bad given you do not have a tail, which is pretty awful aerodynamically speaking)
- trhway 7y agoif tube and wings design is to change, i think it will be some less radical changes than flying wing, more along the lines of transitioning the tube into the lifting body, while may be not the full way along the Burnelli http://www.burnelliaircraft.com/wp/ http://www.burnelliaircraft.com/wp/ , instead more like the modern version https://en.wikipedia.org/wiki/Aurora_D8 https://en.wikipedia.org/wiki/Aurora_D8 : "The aircraft is designed to be over 50% more fuel efficient[1] compared to aircraft currently under production."
- jillesvangurp 7y agoHmm, looks like an x-plane screenshot. It wouldn't surprise me if they've been prototyping with planemaker (included with x-plane). IMHO interesting concept but the thing to be investing in would be electric engines (hybrid or battery) as that will cut fuel costs a lot more potentially. 20% is an incremental improvement and potentially not good enough by the time this gets productized and never mind the time when this gets retired a few decades later (in the best case). So, in short, I think this won't fly (bad pun, sorry) because it's not anywhere near good enough by the time it can reach the market (15+ years?).
- nwah1 7y agoA lot of the proposed efficiency improvements involve new engines, new fuels, or new materials. This is a new design which could stack on top of any of these other improvements. Including a hybrid or electric engine.
- jillesvangurp 7y agoMaybe but the primary driver of this design is the fuel tanks and weight distribution as well as the need for having big heavy jet engines. This thing still takes about 140 tonnes of fuel. That's a lot of money to fly from A to B using a plane that is still a decade+ away. All I'm saying is that 20% cost reductions is not nearly ambitious enough for that type of long term project given the stuff that is already happening today and given the stuff that is likely to happen in the next decade.
- fernly 7y agoSorry, but this thing, head on, is pure FSM.
- FreeInFlorida 7y agoTwice the fuselage weight, cost for same number of seats, plus two gigantic engines located well aft of Center of Pressure. There’s a good reason we don’t see any aircraft with a design like this today. It doesn’t work financially or aerodynamically.
- tempestn 7y agoLooking at the design, the first thing that occurred to me is that it looks like the frontal surface area would be increased compared to a traditional commercial jet with the same wingspan, which I would expect to negatively impact fuel efficiency. I did a bit more thinking and some reading to try to determine why this isn't the case. For one thing, while the split fuselage in the images appears similar to that of a conventional airliner, I expect it would actually be considerably shorter than that of a jet with comparable capacity, the reason being that much of the luggage and equipment that would normally be stowed below the passenger compartment could instead be relocated to the center of the 'v'. You would still have somewhat more frontal surface though I would think. Perhaps this could be outweighed (no pun intended) by weight savings and lower surface area. Although I wonder if some of the savings would have to come from flying more slowly, which this design might facilitate. I don't know anything much about aeronautics though, so would love input from someone who does!
- anordal 7y agoAre the wings at the back doing anything useful so far aft of the center of mass, uh, behind the rest of the craft?