[HN Gopher] Engineers are exploring radical new designs for comm...
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Engineers are exploring radical new designs for commercial planes
Author : prostoalex
Score : 76 points
Date : 2022-11-10 18:24 UTC (4 hours ago)
(HTM) web link (www.wsj.com)
(TXT) w3m dump (www.wsj.com)
| Someone wrote:
| 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."_
| xhkkffbf wrote:
| 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.
|
| https://www.amazon.com/747-Jumbo-Revolution-Christopher-Spen...
| alexpotato wrote:
| 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".
| VBprogrammer wrote:
| 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?
| dan_quixote wrote:
| The ribs are already all different across existing commercial
| airplane wings.
| VBprogrammer wrote:
| Across the wings yes but not across the majority of the
| fuselage.
| scarier wrote:
| How is that a meaningful distinction from either a design
| or manufacturing standpoint?
| dr_orpheus wrote:
| 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.
| bumby wrote:
| > _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_
|
| The pressures may be equal, but the stress (what I assume
| you mean by pressure forces) is what matters. The hoop
| stress is double the longitudinal stress (which is why
| pressure vessels almost always tend to fail by splitting
| along the longitudinal axis, despite both the
| longitudinal and radial axis' experiencing the same
| pressure). That would make me think the stress at the
| ends isn't as much of an issue, but I guess funky designs
| can act as stress concentrations.
| scarier wrote:
| 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.
| aclatuts wrote:
| If the all the manufacturing techniques have to change, maybe
| 3d printing some parts or the whole plane would make sense
| and be viable.
| scarier wrote:
| 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.
| [deleted]
| dublin wrote:
| 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..."
| nicktelford wrote:
| 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.
| amelius wrote:
| Banking isn't a problem in practice or your coffee wouldn't
| stay in your cup while standing on the table.
| dublin wrote:
| 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...
| chrisBob wrote:
| 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.
| rootusrootus wrote:
| 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.
| gauravjain13 wrote:
| 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.
| QuadmasterXLII wrote:
| ?
| AnimalMuppet wrote:
| Not if the pilot did it right. The net force on you
| should always be directly toward the floor.
| alistairSH wrote:
| Even when the plane is tipped over at 15* (or whatever
| their max bank angle happens to be)? The floor is no
| longer directly underneath you.
| vel0city wrote:
| Underneath is a relative term.
| orangepurple wrote:
| 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.
|
| The ground is whatever you accelerate towards.
| edh649 wrote:
| Balanced out by the centripetal force of the plane
| turning!
| MiscCompFacts wrote:
| I wonder if this could be solved by a rotating inner
| cabin that always maintain perpendicular to force of
| gravity when the plane banks?
| cwillu wrote:
| 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.
| aaronblohowiak wrote:
| depends on the flight paths for different airports. some
| require tighter turns.
| dan_quixote wrote:
| Pilots can control the bank acceleration, sure. They have
| much less control over acceleration due to uneven
| turbulence.
| thot_experiment wrote:
| 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.
| hindsightbias wrote:
| 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.
| thot_experiment wrote:
| Good to know, I'm aware that high roll-rate turbulence is
| _possible_ but presumably quite rare?
| nunez wrote:
| 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
| dublin wrote:
| 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...
| flaviut wrote:
| Not a pilot, but I've flown in the MD-80 once, and I've
| found it much more unpleasant than most planes due to the
| engine noise in the cabin.
|
| But on the other hand, I've never experienced turbulence
| that's made me more than barely uncomfortable in any
| plane.
| HPsquared wrote:
| In a typical plane in turbulence, you can see the wings
| bending up and down. Perhaps a blended wing would be
| stiffer, though.
| gcanyon wrote:
| 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.
| thot_experiment wrote:
| 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.
| HPsquared wrote:
| 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)
| codesnik wrote:
| they don't have to be shallower, just bank angle increase
| should be slower than usual.
| scarier wrote:
| I mean, the rise of low-cost carriers has shown pretty
| clearly that passengers are willing to put up with a lot for
| cheaper tickets...
| fshbbdssbbgdd wrote:
| I wouldn't want that on a red-eye, but it would add some
| entertainment to a one-hour flight.
| moffkalast wrote:
| Would legit pay extra for the fun ha
| dongobongo wrote:
| people in the center, cargo in the peripherals
| aeternum wrote:
| It might be good to have a disincentive for the peripheral
| window seats. Some also find that feeling of falling /
| turbulence enjoyable.
| aaronblohowiak wrote:
| this issue is why the startup in socal is focusing on air
| freight for their flying wing design.
| giantg2 wrote:
| 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.
| PicassoCTs wrote:
| >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.
| jcampbell1 wrote:
| 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.
| shkkmo wrote:
| 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.
|
| https://www.technologyreview.com/2013/01/24/180345/hybrid-
| wi...
| scarier wrote:
| 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.
| runarberg wrote:
| I see. So this is why a flock of geese flies in a single
| file, rather then, say, a V shape.
| jjk166 wrote:
| Aerospace engineer here, this is incorrect.
|
| 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.
| coredog64 wrote:
| 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)
| strongpigeon wrote:
| You seem knowledgeable about this. Do you mind expanding on
| why these aren't more efficient?
| schiffern wrote:
| 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]
|
| [1] https://en.wikipedia.org/wiki/Wetted_area
|
| [2] https://www.youtube.com/watch?v=IWBaddGG6z8
| kridsdale2 wrote:
| 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.
| jdhendrickson wrote:
| I'm curious if your thinking on this matter has changed based
| on the replies you have received ?
| dr_orpheus wrote:
| > 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.
|
| [0] https://en.wikipedia.org/wiki/Skin_friction_drag
| nervousvarun wrote:
| This "problem" goes away if you just have one of the feeds in
| the seat-back entertainment system be a wing mounted camera
| view no?
| tengbretson wrote:
| 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?
| nordsieck wrote:
| > 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
| kridsdale2 wrote:
| Maybe if you had it in stereo 3D and gave the passengers a VR
| display.
| JustSomeNobody wrote:
| Anecdotally, I hate flying if I can't see out the window. Like,
| really really hate it.
| blamazon wrote:
| 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!
| horsawlarway wrote:
| 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.
| culopatin wrote:
| 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.
| dublin wrote:
| 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!
| Symbiote wrote:
| At least in Europe having the blinds open (and the lights
| dimmed at night) is an airline requirement.
|
| https://news.schiphol.com/why-do-the-window-blinds-have-
| to-b...
| willcipriano wrote:
| They didn't have the magical rectangle when you were a
| kid. Might miss some celebrity vacation pics if you take
| your eyes off it.
| aeternum wrote:
| 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.
| RubberbandSoul wrote:
| I've heard the opposite. Keeping the shades open is so
| that the rescue crews can look into the plane in case of
| a crash/accident.
| lvspiff wrote:
| 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.
| nunez wrote:
| yup it's insanely annoying
|
| 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
| anthomtb wrote:
| 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".
| blamazon wrote:
| You're still a hero. Thank you for sleeping so I don't
| have to feel awkward making you think I am looking at you
| while looking out the window.
| AnimalMuppet wrote:
| 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.
| abeppu wrote:
| 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
| giantg2 wrote:
| "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.
| camillomiller wrote:
| Call me when they've solved seats in such planes.
|
| 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.
| FriedPickles wrote:
| 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.
| willnonya wrote:
| 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.
| FriedPickles wrote:
| 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.
|
| 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/s
| tory.php?storyId=212692...
| RandallBrown wrote:
| Why can't you? Steeper banks will be a small problem, but
| people ride rollercoasters and most of the time planes fly
| straight.
| iLoveOncall wrote:
| 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):
|
| 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.
| PicassoCTs wrote:
| 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.
| bmitc wrote:
| All I can think is: yea, they're called high-speed trains.
| moffkalast wrote:
| They really ought to get around to building that transatlantic
| track
| shahbaby wrote:
| Who will be held accountable when this fails and people die?
| aeternum wrote:
| 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?
| inkcapmushroom wrote:
| 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.
| davidw wrote:
| As someone who does not like heights or flying, I would gladly
| sit smack in the middle of the wedge-shaped plane.
| rdtwo wrote:
| 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.
| scarier wrote:
| 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.
| rdtwo wrote:
| It's the details that get you. Things like door designs
| visibility, control expectations.
| carabiner wrote:
| 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.
| ozzythecat wrote:
| 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.
| keepquestioning wrote:
| Tell them to work for Boom Aerospace.
| carabiner wrote:
| 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.
| renewiltord wrote:
| Scenes when airport design constrains this more than engineering.
| AlexandrB wrote:
| https://archive.ph/hJUp6
| TheRealPomax wrote:
| 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.
| [deleted]
| ramesh31 wrote:
| 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.
| upofadown wrote:
| >With total power loss, they become completely uncontrollable.
|
| * 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.
| inkcapmushroom wrote:
| >speed, reliability, and safety
|
| 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.
| daveslash wrote:
| 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.
| throw827474737 wrote:
| Dito, but before doubting myself.. radical new, wow.
| AlexandrB wrote:
| 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".
| jabl wrote:
| 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.)
| ramesh31 wrote:
| 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.
| jabl wrote:
| 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?
|
| See also SAS flight 751, where ice broke off from the
| wings and were ingested into the engines https://en.wikip
| edia.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?
| hotpotamus wrote:
| 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.
| robocat wrote:
| Plus having more engines doesn't help if failures are
| correlated, such as some fuel issues, or
| http://news.bbc.co.uk/2/hi/uk_news/magazine/8622099.stm
| coredog64 wrote:
| Extended Twin Operations.
| jabl wrote:
| 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.
| [deleted]
| runarberg wrote:
| 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.
| dver wrote:
| Here's some info on stability, https://www.sciencedirect.com/sc
| ience/article/pii/S100093612....
|
| I think you're thinking of pure flying wings.
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