[HN Gopher] Goodyear Inflatoplane
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Goodyear Inflatoplane
Author : carabiner
Score : 146 points
Date : 2024-05-02 06:22 UTC (2 days ago)
(HTM) web link (en.wikipedia.org)
(TXT) w3m dump (en.wikipedia.org)
| helpfulContrib wrote:
| I've always wanted one of these - they seem like an awesome way
| to explore the world. I once fantasized about getting a couple of
| them dropped in some remote location, spend a few days or weeks
| hiking out there, and then flying back.
|
| Wonder what a modern variant would look like?
| k7sune wrote:
| Something like a powered paraglider comes to mind. It has the
| additional benefit of being reusable.
| rbanffy wrote:
| Imagine now it could have a much larger pressurised cabin.
| hi-v-rocknroll wrote:
| Why rely on an inflated wing that can be punctured or change
| in stiffness with temperature and altitude when fiberglass
| and carbon fiber rods exist?
| helpfulContrib wrote:
| Portability and durability.
|
| Imagine a version with modern drop-stitch technology .. [1]
|
| [1] - https://www.yachtingworld.com/yachts-and-gear/the-
| new-inflat...
| mysterydip wrote:
| I wonder how much it could be impoved if this project was
| revisited today with modern materials and manufacturing
| techniques.
| rbanffy wrote:
| Not sure modern safety standards would be friendly to it.
| throwup238 wrote:
| It's 225 lbs empty so it qualifies as an ultralight aircraft
| like powered hand gliders. It's a class that's much easier to
| certify and has many fewer safety requirements.
| claudex wrote:
| They will self-certify themself and the problem disappear.
| usrusr wrote:
| Rigid flight needs exactly this, rigidity. But we do have
| inflatable flight: paragliders, first flight only a few years
| after the inflatoplane. Inflated only by the dynamic pressure
| from forward movement, but they make up what they lack in
| pressure differential with using more bracing wires (much
| more). But the inflatoplane relies on bracing wires as well, so
| the difference could be considered surprisingly small.
| londons_explore wrote:
| I think there are lots of possibilities for inflatable vehicles
| _which cannot be deflated_.
|
| For example, make a flimsy structure out of thin steel foil, then
| pressurize it to give it far more strength than it would
| otherwise have.
|
| Same as the strength of a coke can.
|
| Except with steel as the tensile material, you can probably use
| pressures up around 1000 psi, making the whole structure have an
| amazing strength to weight ratio.
| Gare wrote:
| > Except with steel as the tensile material, you can probably
| use pressures up around 1000 psi, making the whole structure
| have an amazing strength to weight ratio.
|
| Congratulations, you have created a bomb.
| londons_explore wrote:
| You certainly need to think about that in the design. But by
| rolling a 'texture' into the sheets the structure is made
| from, you can make sure that any hole can't 'rip' bigger, and
| therefore fails slowly rather than rapidly.
|
| You also need pressure regulator valves in case of fire.
|
| And you might want to make the whole thing double or triple
| skinned so the highest pressures can be deeper inside where
| they are less likely to get punctured/less vulnerable to
| corrosion damage/crash damage.
| usrusr wrote:
| But when do you really need a structure that has this
| exceptional strength on the happy path, but would still be
| good enough in terms of safety when pressure is lost?
|
| Unmanned aviation comes to mind, but the ratio between
| structural mass and battery+payload is already so low, even
| a zero-mass structure would not make a meaningful
| performance difference. It's all about the battery tech.
|
| Scaling up foil boating perhaps? Carbon fiber construction
| would certainly appear like a good candidate for taking
| advantage of being pressurized, and I perhaps naively take
| it as a given that materials is the major limiting factor
| in scaling up.
| londons_explore wrote:
| > still be good enough in terms of safety when pressure
| is lost?
|
| You might not design for that case. A suspension bridge
| can't survive a tower falling over, or a cable snapping.
|
| The pressurized structures wouldn't be able to survive
| leaks over X size, and for leaks under X size,
| compressors would be used to maintain pressure.
| londons_explore wrote:
| Rockets are the obvious use. The structure of a rocket is
| far heavier than the payload, and every kilo of weight
| you can shave off the rocket, you can add to the payload.
| buran77 wrote:
| At that point you're not dealing with a "flimsy structure
| out of thin steel foil" that you can inflate to hundreds of
| psi. You described what's basically a submarine, multiple
| high and low pressure hulls able to withstand hundreds of
| psi of pressure.
|
| Just for some reference, 1000psi is the kind of pressure
| you get ~700m depth (2300ft), double what a submarine would
| regularly withstand. Pressure in your average propane gas
| tank probably peaks around 200psi in high temperature. That
| steel isn't flimsy, it tends to get bulky and heavy even
| with creative ribbing and reinforcement.
|
| It has to make a lot of sense practically and economically
| to consider such an option. So it ends up being used in
| places where weight or cost matter less.
| londons_explore wrote:
| A CO2 fire extinguisher is about 1000 psi.
| buran77 wrote:
| A 1000psi fire extinguisher uses ~5mm thick steel even
| for that relatively small diameter cylinder. A _typical_
| extinguisher is ~200ish psi with a wall probably ~1mm
| thick.
|
| This highlights that high pressure and "thin steel foil"
| do _not_ go well together and don 't scale in your favor.
| Pressure makes any failure considerably more dangerous.
| rbanffy wrote:
| Wasn't the Centaur upper stage pressurised. I remember an
| incident where one collapsed under load because the tank lost
| pressure.
| GuB-42 wrote:
| Well, rockets are essentially bombs we try to make explode
| in a controlled manned. The "controlled" part is not always
| successful.
|
| Fueled rockets are treated like live bombs. No one around
| except for people who really need to be (like astronauts).
| dylan604 wrote:
| > The "controlled" part is not always successful.
|
| I'm assuming you're referring to the unnominal situations
| resulting in the unscheduled rapid disassembly
| procedures? I wonder how many people watch launches with
| similar intent as NASCAR races where they're just looking
| for the crashes or hockey games looking for the fights?
| GuB-42 wrote:
| I must admit I tend to watch SpaceX test flights for the
| potential fireworks.
|
| But for, say the JWST launch, it really wasn't with the
| same intent.
|
| In the former, it is just SpaceX way of doing business,
| no big deal, no significant payload being destroyed and
| the next rocket is on the line. The latter is the result
| of billions of dollars, many years of work and great
| scientific promises that could be blown to pieces.
|
| And of course, for manned flight, who in their right mind
| wants astronauts dead?
| dylan604 wrote:
| > And of course, for manned flight, who in their right
| mind wants astronauts dead?
|
| Which begs the question, who wants to fly Starliner?
| rbanffy wrote:
| Or Orion's heatshield for that matter. Orion 2 should
| have the attachment mechanism redesigned, most likely as
| arms attached to the upper side of the reentry vehicle
| rather than in holes in the shield itself.
| rbanffy wrote:
| Even on SpaceX launches I'm rooting for the rocket.
| JKCalhoun wrote:
| That was in fact an innovation that followed the German V2
| -- dropping the framework structure of the rocket in favor
| of relying solely on the skin of the tank under pressure to
| give structural integrity of the rocket.
|
| "The tank of the Atlas consisted of stainless steel which
| was no thicker than a dime at any point. Generals, and
| later congressmen, worrying about what would happen if
| somebody dropped a wrench on such a tank were conducted to
| a test version of the "stainless steel balloon" that was
| stiffened by pressure and offered a choice of assorted
| mallets to see whether they could dent it. In each case the
| general or congressman grew tired before he had even
| succeeded in producing a mark that could be seen."
|
| Willy Ley's "Rocket's, Missiles and Men in Space"
|
| https://archive.org/details/rocketsmissilesm00leyw
| icegreentea2 wrote:
| Yes, the Centaur upper stage was and still is using balloon
| tanks.
|
| I think this is the failure you're referring to:
| https://www.youtube.com/watch?v=imkdz63agHY
|
| And here's a picture from ULA/Tony Bruno showing a Centaur
| tank in their factory, being supported by a rig:
| https://twitter.com/torybruno/status/1435553806792728579
| xattt wrote:
| I believe that the Apollo LM also depended on
| pressurization for structural strength.
| euroderf wrote:
| Atlas too. Thin aluminum shell.
| whamlastxmas wrote:
| Especially if Boeing is involved
| scubazealous wrote:
| It would be cool, especially with advances in plastics you
| could layer over the steel to protect it from corrosion like
| what they do with soda cans.
|
| For reference, a steel or aluminum SCUBA tank is usually filled
| to 3000psi and when I fill steel tanks I can hear and sometimes
| see the metal start to slightly balloon. This is normal because
| steel is not brittle but it is very strong.
|
| There is a lot of rules put in place for safety though. A tank
| has to be visually checked by a professional every year and
| hydro statically tested every 5. The danger is any
| rust/corrosion weakening the metal and causing it to rupture.
| More often seen in aluminum tanks, which is one reason I prefer
| steel.
| marcosdumay wrote:
| Yes, in theory steel is not the best material for a high-
| pressure tank.
|
| We use it because it's cheap and well tested. But we are
| probably better of with a layered combination of a few
| different materials. Steel may not even enter it.
| Semaphor wrote:
| Also discussed in 2019:
| https://news.ycombinator.com/item?id=21249801
| mapleoin wrote:
| People knew how to name things back then.
| mhh__ wrote:
| Nothing will ever top shark repellent bat spray
| buildsjets wrote:
| I fly a Cessna from the time period with a Nav-O-Matic
| autopilot, Land-O-Matic landing gear, and an Omnivision window.
| knodi123 wrote:
| Okay, I had to look that one up, and:
|
| > Omni-Vision - The [term for the] rear windows on some
| Cessna singles, starting with the 182 and 210 in 1962 and
| followed by the 172 and 150 in 1963 and 1964 respectively.
| The term was intended to make the pilot feel visibility was
| improved on the notably poor-visibility Cessna line. The
| introduction of the rear window caused in most models a loss
| of cruise speed due to the extra drag, while not adding any
| useful visibility.
|
| That's hilarious.
| carabiner wrote:
| Today it'd be some vague crap like "Float."
| ansible wrote:
| Mustard did a video on this.
|
| Nebula (subscription required): https://nebula.tv/videos/mustard-
| escape-in-an-inflatable-air...
|
| Youtube: https://www.youtube.com/watch?v=GJ-4uWwQ5HA
| cousin_it wrote:
| Can we make an aircraft with a motor and inflatable wing, such
| that the motor works for propulsion and also inflating the wing,
| and the motor's waste heat is used for heating the air in the
| wing?
| yaakov34 wrote:
| That's how this plane worked - the inflation pressure in flight
| was supplied by the motor. I don't think heating the air was
| desired, but some heat will inevitably end up in the air as it
| is compressed.
| rbanffy wrote:
| You could use engine exhaust to inflate the wings.
| UniverseHacker wrote:
| I wonder if this is more practical nowadays. Modern "drop stitch"
| inflatable kayaks and paddle boards are extremely rigid, strong,
| light, and reliable. They also have precise 3D shapes determined
| by the length and position of the internal drop stitch threads.
| Has anyone tried using that tech to create an inflatable
| airplane?
| plasticchris wrote:
| Feels like an opportunity to make a very cool ultralight given
| the weight savings, and no pilot license is needed (though
| still recommended...)
| RajT88 wrote:
| DLC in a Fallout game
| mapt wrote:
| Google recommends the Woopy-Fly inflatable ultralight, though
| it's not clear whether it's actually in production
|
| Discussions are not optimistic, but do invoke some related
| inflatable craft -
| https://www.reddit.com/r/WeirdWings/comments/n7a4k1/what_hap...
| UniverseHacker wrote:
| Haha, that looks incredibly dangerous. A floppy hang glider
| with much less lift and stability than a regular hang glider,
| and it needs continuous electrical power and two working fans
| to stay inflated.
|
| If I've learned anything from youtube - flying is not an
| expensive or inaccessible hobby. But safe flying is.
| LeifCarrotson wrote:
| My inflatable SUP is nice, and it is impressively rigid, but I
| wouldn't say it's light. I got the inflatable because it can be
| stored and transported compactly. Competition paddleboards and
| kayaks are fiberglass/composite foam sandwiches, and way
| lighter than the inflatable variants.
|
| I think the inflatable SUPs and kayaks are as heavy as they are
| because of the thick layers of vinyl and nylon that prevent
| punctures and abrasion.
|
| Kitesurfing kites are made of lightweight ripstop polyester,
| with a super-thin urethane coating, and have an inflated
| bladder to help hold their shape. That might be more
| appropriate tech for creating an airplane.
| UniverseHacker wrote:
| Yeah, I'd think you'd want to apply that principle, but with
| different materials for an aircraft. Off the top of my head I
| am thinking dyneema threads inside (instead of
| dacron/polyester) and a carbon fiber/mylar composite for the
| outside cloth, like is used for high end racing sails on
| sailboats.
|
| I don't have experience with hard SUPs but have a cheap
| RetroSpec weekender 10'6" SUP at 17.5lbs - I quickly looked
| up the weight of similar size composite boards (e.g. Isle 2)
| and was seeing more like 24lbs. I googled "competition SUP"
| and found some at 17lbs in the same length as my inflatable,
| but much narrower and 100lbs lower in max weight capacity
| than the inflatable SUP of the same weight.
|
| For kayaks, high end drop stitch kayaks are about half the
| weight of rotomolded plastic ones of the same size, and only
| slightly heavier than skin on frame kayaks made from exotic
| materials, which are the lightest kayak technology and
| slightly lighter overall.
| nikitaga wrote:
| I'm not 100% sure that they used drop stitch, but the company
| Prospective Concepts developed a few more modern designs of
| inflatable wings for various applications.
|
| https://repository.tudelft.nl/islandora/object/uuid:306785d0...
|
| https://www.prospective-concepts.ch/html/site_en.htm (click
| "Projects" > "Air" on the right)
|
| Personally I think this is a technological dead-end, at least
| for the civil aviation use cases that I understand. The only
| advantage of an inflatable system is compactness / portability,
| but since the Inflatoplane, that's been solved in many other
| ways by rogallo wings, hang glider type wings, paragliders,
| parachutes, various types of fold-out rigid wings, etc.
|
| And all of the _other_ properties of inflatable wings aren 't
| advantageous other. They're not simpler, lighter, stronger,
| more durable, or more reliable than the alternative best
| option, and they don't seem to have a particularly good mix of
| useful properties to win against the other best alternative for
| any given use case, even if you assume modern materials and
| modern techniques.
| klyrs wrote:
| > The aircraft was in a descending turn when one of the control
| cables under the wing came off the pulley and was wedged in the
| pulley bracket, locking the stick. The turn tightened until one
| of the wings folded up over the propeller and was chopped up.
|
| While the pulley system at the root cause of this could be
| improved, the failure mode of "floppy wing got chopped up by
| the prop" seems like there could be quite a lot of ways to get
| there. Dunno what you think we've done in the last 50 years to
| improve on this situation, but for anything other than an
| emergency, I wouldn't want to bet my life on a vehicle like
| this. Also, I'm having trouble picturing an emergency that
| would be resolved by an inflatable plane.
|
| Nevermind, I've got it. A single container could hold a hundred
| inflatable airplanes. That'd be a helluva surprise deployment,
| if you don't value the lives of your pilots.
| scubazealous wrote:
| Today this would most likely have the same drawbacks as the
| inflatable kayaks we see for sale. Saves on space (and money?)
| and could be good as an entry into a hobby but at any
| intermediate to advanced level there are better options to choose
| from. With the high barrier to entry to flying I think most
| pilots would opt for the most reliable option from the start.
|
| I would not want to be caught in inclement weather in an
| inflatable anything.
| IG_Semmelweiss wrote:
| What if you are stuck in north korea and the duffel bag
| containing this landed just at your patio ?
|
| I am surprised this was not pursued more aggressively, in fact.
| whamlastxmas wrote:
| Pretty sure NK would easily shoot this out of the sky
| IG_Semmelweiss wrote:
| Is this true if you are invisible to radar ? (i assume
| inflatables absorb radio waves much better than metal?)
|
| Or flying low ?
| bloopernova wrote:
| Would inflatable wings/bodies work on Mars or a similar low
| pressure environment?
| hi-v-rocknroll wrote:
| If you searched the web, inflatable bodies have been used. The
| problem is Mars atmosphere is 2% and gravity is 38% that of
| Earth's. Gravity-corrected wing loading to reach the equivalent
| of say a small plane on Earth would require 20x the wing area.
|
| A proposal demonstrator of this was suggested in a paper:
|
| https://www.icas.org/ICAS_ARCHIVE/ICAS2014/data/papers/2014_...
| tooltechgeek wrote:
| wouldn't the lower density be equivalent to a higher altitude
| on earth? Propellers would be not effective but some type of
| jet or rocket would?
| hi-v-rocknroll wrote:
| Sure. It likely also means different wing geometry and it
| needs to move faster.
| frankus wrote:
| I've noodled around with something like this for a climate-
| controlled micromobility vehicle. Something like the Nimbus but
| built with ebike components (https://nimbusev.com -- godspeed to
| them because I really want them to succeed, in part so I can buy
| one).
|
| I'm _pretty_ sure it would be ridiculous and impractical, but we
| could use a way to solve the "it's only five blocks away but the
| weather's miserable" in a way that doesn't involve huge parking
| lots and otherwise terrible land use.
|
| I know that there must be clothing that solves this, but donning
| a whole suit for what might be a 90-second trip is a lot of
| friction, especially when the alternative is feeling a little bit
| guilty about driving for a trip that could easily be
| biked/walked/etc.
| pbronez wrote:
| Nimbus looks super cool! I'd love to try one. Top speed of
| 50mph suggests it's not enough car for highway commuting,
| unfortunately.
|
| I'm more excited about the Aptera. I think it's significantly
| bigger and more highway-capable than the Nimbus, while still
| much more efficient than contemporary EVs. It'll cost twice as
| much as the Nimbus as well... quite different vehicles other
| than the common 2-front, 1-back wheel configuration.
| ChoGGi wrote:
| The Nimbus S shows 75mph
| metadat wrote:
| Previously discussed in 2019:
|
| https://news.ycombinator.com/item?id=21249801 (26 comments)
| hi-v-rocknroll wrote:
| I saw this in a documentary many years ago as some sort of spy
| aircraft to exfil from a hostile country.
|
| While a cool concept, subsequent ultralight aircraft made this
| design obsolete.
|
| Just don't get shot at or have a leak. While it could be very
| compact to transport, it's not very practical or robust.
|
| Also, the service ceiling and service floor(?) could vary based
| on temperature. For example, if it started at sea level and very
| cold conditions, it's possible it could not exceed a certain
| altitude below the need for a pressurized cabin and below its
| performance coffin corner.
| crashmat wrote:
| It says because of the airflow from the engine it could be
| punctured by up to 6 .30 calibre bullets and maintain pressure.
| Is this enough resilience? (I don't really know about aircraft
| combat)
| hi-v-rocknroll wrote:
| So it's a flying bouncy castle or flying tube man. Makes
| sense. Imagine it would be extra fun if there were an
| inflatable Fokker Dr.I.
| EdwardCoffin wrote:
| Neal Stephenson's novel _Seveneves_ [1] included something like
| this (early in part 3), and it being inflatable wasn 't even the
| coolest thing about it.
|
| [1] https://en.wikipedia.org/wiki/Seveneves
| 1-6 wrote:
| Just be careful of thumbtacks in your carryon.
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