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This product is for towing behind another aircraft, but what about winch towing? A winched glider implements flight with renewable electricity and it does so e
by gorgoiler 1y ago
This product is for towing behind another aircraft, but what about winch towing?
A winched glider implements flight with renewable electricity and it does so efficiently because the power and motor never leave the ground!
A glider can climb up to 5000 feet and travel 50x that before making a landing. Wouldn’t it be glorious to see cargo being autonomously slung from site to site across the world, powered entirely by green electricity?
- stinkbeetle 1y agoDo you mean laying out 50 mile long cables from place to place with big engines on the ground that pull in a cable at a couple hundred miles per hour after a plane attaches to it? That wouldn't work. Not even if you skipped tow out a cable from your departure point so it could be reused. And if you had a track for the cable to run in or a carriage holding the winch to drive travel along, then you would just make it rail freight.
- wiml 1y agoNo. Winch glider launches (which are not a new thing) use a ground-based winch to give the glider an initial impulse, and the glider uses that to gain altitude and then glide for a much longer distance. https://glidingschool.com/briefing-winch-launch/ https://glidingschool.com/briefing-winch-launch/
- stinkbeetle 1y agoWell then it's even simpler, carrying any worthwhile amount of cargo in a winch launched glider is not going to work.
- wildzzz 1y agoIt would work fine for sending small payloads short distances but unless you're in a hurry, it would be much easier to just send more mass by truck or train. One big benefit is having a truck or train being able to return to its origin without requiring another launch facility and also being able to travel in nearly all weather. There may be some use cases where drone gliders could airdrop payloads and return to their origin. But again, this requires very specific circumstances like good weather, a lack of roads, unavailability of av gas or jet fuel, and enough cleared space to launch a glider. I do see winches as a good way to launch lightweight fixed wing drones to reduce the amount of fuel and engine size required to deliver payloads. You'd only need to account for the fuel and power required to sustain cruise if you could winch a drone into the sky. You'd get even more distance if the drone was never intended to return like a kamikaze weapon. A small clearing in a field in Ukraine could launch cheap fixed wing kamikaze drones all day long.
- stinkbeetle 1y agoIt wouldn't work very fine at all. Gliding at low speed a minuscule payload 50-100 miles that you have to transfer to the airport at the departure point then from the airport at the destination will almost certainly take longer and be much more expensive in terms of infrastructure and worker cost than just driving it point to point in a delivery vehicle. It's also highly weather dependent, much more so than powered aircraft. If you're really in a hurry you need a helicopter. Then pay your indulgences to some politician's shady "carbon credit" corporation if you feel guilty about your climate sin, or use a carbon-neutral manufactured kerosene for it, and then you're even greener and still cheaper than the unpowered spruce goose idea.
- eptcyka 1y agoTraditionalcgliders are incredibly light, I doubt anything careying sufficient cargo will be able to do a 50:1 distance to altitude ratio.
- roeles 1y agoGlide ratio and weight are not related. Weight shifts the glide Polar to higher speeds and theoretically improves it slightly due to Reynolds effects.
- rkomorn 1y ago"Weight doesn't affect glide ratio" is one of these things I learned why taking flying lessons that still feels counterintuitive every time I read it. (Don't worry, reader, I never intended to get a pilot's license.)
- hermitcrab 1y agoSo, 2 gliders with identical geometry, one standard and one made of lead will have the same glide angle? That sounds unlikely.
- rkomorn 1y agoThere is an asterisk that you have to be at the right glide velocity, but yes: they'll have the same glide angle. The leaden one will just go significantly faster. And yes, it does sound unlikely. That's why I made my previous comment. Here are a couple of many posts on the topic: - https://gronskiy.com/posts/glide-ratio-lift-to-drag-and-weight/ https://gronskiy.com/posts/glide-ratio-lift-to-drag-and-weig... - https://skybrary.aero/articles/glide-performance https://skybrary.aero/articles/glide-performance
- hermitcrab 1y agoThanks for the links. Weight may cancel out of the equations, but (being a bit pedantic) I suspect 'glide angle in independent of weight' only holds up to a point. Taking things to extremes, if the glider is heavy enough that you are going to have to go supersonic then I suspect a lot of the assumptions become invalid. NB/ spherical cows are unable to glide in a vacuum.
- Ruarl 1y agoI'm the wrong kind of engineer to work it out, but I'd be interested to know what the implications for the strength of the cable and specifications for the winch would be for a heavy cargo glider. Thinking on, specifying the weak links and managing failed winch launches (which happen fairly regularly) is interesting to consider. Recreational gliders are light enough to be manoeuvred by hand, although old farm tractors are used to move them more than a few dozen feet. How would all that work?
- mhb 1y agoMaybe this problem is adjacent to catapult launchers on aircraft carriers.
- hermitcrab 1y agoI've done a few gliding flights. They were all towed to height by a powered aircraft and then released. Winch launch is an alternative to towing, but sounded like a fairly terrifying alternative where you were yoinked into the air by a huge winch. The terror isn't an issue if the glider is pilotless. But IIRC they used something like a 7 litre engine to winch an incredibly light glider. Presumably it would require something really powerful to launch a cargo glider.
- bewo001 1y agoI did once fly as a guest with a winch start, and yes it is something. The ascend is pretty steep and the acceleration is powerful. The pilot did not find good lift and we had to land shortly after. My stomach did not like his curving around looking for lift, so I wasn't too unhappy about the short flight.
- dimensional_dan 1y agoI have done it. It's actually quite thrilling, feeling that initial burst of acceleration.
- bombcar 1y agoThe we simplify it by putting the winch on rails, and give the glider wheels, then we can chain them together and then we’ve reinvented the railroad, badly.
- renewiltord 1y agoYes, then we could put wheels on my grandmother and we would have invented a bicycle badly https://youtu.be/A-RfHC91Ewc?si=uMjPf00zqbJHfSwn https://youtu.be/A-RfHC91Ewc?si=uMjPf00zqbJHfSwn We are so smart that we can take good things and modify them in stupid ways to make bad things. This is, in fact, very smart of us. Winch launching is already a thing https://youtu.be/U3ztaJ0yfxE?si=1AjAS8F8-pCaUFZI https://youtu.be/U3ztaJ0yfxE?si=1AjAS8F8-pCaUFZI
- potato3732842 1y agoBuilding a railroad over water or through a jurisdiction full of jerks is expensive. I can see a big winch glider being worthwhile in some very limited circumstances.
- korse 1y agoNah. You've messing up something 4chan worked out years ago. You need a BLIMPTRAIN! Locomotive on rails towing a train of lighter than air vehicles that can detach under optimal conditions/location to deliver their cargo over the last mile.
- kakacik 1y agoTry loading 10 tons into some glider and shooting it up. First the winch would have to be absolutely massive, second its highly reliant on at least a bit good weather and nobody glides around during night. Pilotless doesn't remove danger of it falling onto some roof, so automation would have to be pretty much flawless. Truck, you can load and send it much further than any glider can ever glide, any time, any day. Also throughput of highways is much bigger than airports, and you can deliver it literally to the target doors. Not a very practical fantasy it seems.
- beAbU 1y agoCan you please ELI5 winched gliding to me? Is a glider basically joinked into the air by a large and fast winch, and then detached and the glider glides on it's own "power" back to the landing? Or is the winch at the destination, with a cable going _all_ the way across the landscape to where the launch point is, so that it can pull the glider over? I'm a tad confused.
- gorgoiler 1y agoYou nailed it: the winch pulls the glider rapidly up to altitude, lets go, and the glider floats back down to earth.
- rkomorn 1y agoThe winch launches the glider and gives it speed from the ground that it can then convert into enough altitude (ie time) for the pilot to find a rising air current (ideally, I guess). Edit: so yes, your first thought is correct. :) It's somewhat similar to an aircraft carrier launch except that the glider can get a lot more altitude out of it.
- drpixie 1y agoWinch launches are a lot like a kid with a kite. Run fast (wind in the winch) to get speed and up it goes. At its desired altitude, the glider disconnects and goes on its way. https://youtu.be/YePIJKs5me0 https://youtu.be/YePIJKs5me0 gives you an idea. On a day with a decent breeze, it is possible to "kite" a glider up to very high altitude by letting the wire out again. But this is highly frowned upon because it means there is a very long (and nearly invisible) wire dangling right through the airspace used by other aircraft!
- decafninja 1y agoHow about a carrier style electromagnetic catapult to launch the glider? Except make it ski jump style so that the glider gains initial altitude. (Now that I mention it, why don’t carriers combine both catapult and ski jump?)