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I wonder if this is more practical nowadays. Modern “drop stitch” inflatable kayaks and paddle boards are extremely rigid, strong, light, and reliable. They als

by _yb2s 3y ago

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 3y ago
Feels like an opportunity to make a very cool ultralight given the weight savings, and no pilot license is needed (though still recommended…)
RajT88 3y ago
DLC in a Fallout game
mapt 3y ago
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_happened_to_woopy_fly_i_remember_seeing/ https://www.reddit.com/r/WeirdWings/comments/n7a4k1/what_hap...
- _yb2s 3y ago
  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 3y ago
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.
- _yb2s 3y ago
  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 3y ago
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-f75b-4378-a145-75905c83efa7/datastream/OBJ/download https://repository.tudelft.nl/islandora/object/uuid:306785d0... https://www.prospective-concepts.ch/html/site_en.htm 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 3y ago
> 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.

by _yb2s 3y ago

plasticchris 3y ago

Feels like an opportunity to make a very cool ultralight given the weight savings, and no pilot license is needed (though still recommended…)

RajT88 3y ago

DLC in a Fallout game

mapt 3y ago

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_happened_to_woopy_fly_i_remember_seeing/ https://www.reddit.com/r/WeirdWings/comments/n7a4k1/what_hap...

_yb2s 3y ago
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 3y ago

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.

_yb2s 3y ago
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 3y ago

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-f75b-4378-a145-75905c83efa7/datastream/OBJ/download https://repository.tudelft.nl/islandora/object/uuid:306785d0... https://www.prospective-concepts.ch/html/site_en.htm 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 3y ago

> 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.