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We have jetpacks and we do not care (theguardian.com)
333 points by zdw on Jan 27, 2022 | hide | past | favorite | 403 comments

They’re completely impractical, that jet pack does indeed exist, but there are approximately two people in the world who can safely fly it untethered. Every now and again they’ll pop again with “mountain rescue experiment with jet pack” or “Marines demonstrate boarding with jet pack”, and every time it’s just the creator cosplaying as whatever service he’s trying to sell it to this time.

What were we expecting from jetpacks though, really? Is it not more fair to suggest that the past was a little bit naïve about what it would take to operate a jetpack? They're still aircraft after all, at the very least you're going to need pilots license.

There's no "bicycle" of jetpacks, you've got three axis of movement and certain death in every direction but up, it's just not a tool that belongs in the every-man's garage.

I think the same can be said for the past's perception of what flying cars would be like. You don't see your average joe flying a helicopter to work, for the very same reasons you'll never see personal flying cars be ubiquitous.

Actually what's needed was outlined very nicely in Starship Troopers by Heinlein many decades ago. We're not there yet of course but with faster and faster edge compute, it will get there.

> Jump really hard and the suit’s jets cut in, amplifying what the suit’s leg “muscles” did, giving you a three-jet shove, the axis of pressure of which passes through your center of mass. So you jump over that house next door. Which makes you come down as fast as you went up . . . which the suit notes through your proximity & closing gear (a sort of simple-minded radar resembling a proximity fuse) and therefore cuts in the jets again just the right amount to cushion your landing without your having to think about it. And that is the beauty of a powered suit: you don’t have to think about it. You don’t have to drive it, fly it, conn it, operate it; you just wear it and it takes orders directly from your muscles and does for you what your muscles are trying to do. This leaves you with your whole mind free to handle your weapons and notice what is going on around you . . . which is supremely important to an infantryman who wants to die in bed. If you load a mud foot down with a lot of gadgets that he has to watch, somebody a lot more simply equipped—say with a stone ax—will sneak up and bash his head in while he is trying to read a vernier.

Now you're making me want read the book!

A word of caution: start on an evening where you don’t have to work the next day. You’re going to end up reading the whole thing in one sitting.

The entire book is like an extended version of the quote above.

The book is good, but there's a certain amount of black comedy when you look at the context of how it was written and how, among other things, the military strategies it argues for (de facto universal conscription, terrorizing enemy civilians into submission, using shock-and-awe campaigns and targeted strikes instead of needing to occupy territory in depth, etc) have been repeatedly discredited since its release, and even at the time of release had obvious failures in the Korean War just a few years before.

It can still be a good book with terrible politics. If you need a palate cleanser when finished, The Forever War by Haldeman is a direct rebuttal..

I'd argue that if you need a palate cleanser after reading Starship Troopers, go watch the Paul Verhoeven film Starship Troopers which is "surely you can't be serious about this!" take on Heinlein's book.

Although, ironically, he removed the powered-mech suits.

Recommendations: If you want modern powered-mech suits military action, read The Red Trilogy. If you want a cracking sci-fi novel from the same era but very different politics, “Rebel in Time” is a corker.

Universial conscription? No, it's entirely volontary in the book. Completed service is a requirement for full citizenship though. But having done military service is quite rare in the book from what I understand.

Not being considered a citizen is a very clear deterrent to avoiding the "voluntary" conscription.

A "separate but equal" civil organization does not mean that there is true equality. Even less so when they do not even pretend to be equal.

Nobody should take Heinlein's narrators words for granted. He is deservedly famous for being very diverse in presenting the viewpoints of his characters - coming from very different societies.

Yeah, people who read Heinlein and try to sort him into some political camp or other usually latch in to some surface level aspect they think make him side with their opposition. But in doing so must ignore huge conflicts the ideas presented would have with their opposition, even more so, when the books contradict each other. Heinelein writes the public motivations for the people of the societies he presents, and while overly verbose at times, I find it facinating, culture is a crucial aspect of society, and scifi without it often becomes dull.

The moon is a harsh mistress is as much a book about strong friendly AI, as one about alternative ways society could be structured to provide continuity and safety if governments fail to provide. The AI aspect is facinating and much deeper than it seems at first. But if you look closely, there are hints all throughout its quite clever, it just does not care about what its doing, it cares about its friend. It reminds me of the treehouse my neighbours kids once made. The kids tried to make it out of ductape, sticks and plank, and their dad helped them, but also snuck out and nailed a few things and support blocks to make it work.

Also, his politics changed drastically over the course of his life, going from a New Deal Democrat to a Goldwater Republican.

Can you give us an example of one of Heinlein's books with an apparent narrative that is very opposed to Starship Troopers?

I ask because when I read it (way back when), I definitely got the impression this was Heinlein speaking in his own voice / his own opinions.

> I definitely got the impression this was Heinlein speaking in his own voice / his own opinions.

That's exactly what I'm talking about! Read another book, and he'll be speaking his own voice/opinions, to, but they'll be very different.

On books, Heinlein's must read, in my opinion, is "The Moon is the harsh mistress", "Stranger in a strange land" and "Starship troopers", all three being very different. But the one book I would recommend reading first is his lesser known novel, "The door into summer". It is not groundbreaking, but very warm and charming.

Nearly every other one?

I'd recommend The Moon is a Harsh Mistress which is a romp imho, and also happens to be a better insight into his personal politics.

Also, Have Spacesuit Will Travel, Farmer in the Sky, Stranger in a Strange Land and mostly everything by Heinlein, though there was arguably a bit of a drop in quality towards the late end of his career.

I like to think of it as 'early' Heinlein and 'late' Heinlein - although both periods are very enjoyable, sometimes it as if it's two different authors.

The Moon is a Harsh Mistress is probably his novel with the most explicit anti-colonial and anti-fascist themes

> What were we expecting from jetpacks though, really? Is it not more fair to suggest that the past was a little bit naïve about what it would take to operate a jetpack? They're still aircraft after all, at the very least you're going to need pilots license.

You need a pilots license, but you don't need fine motor coordination skills across your entire body PLUS a lot of core strength, in addition to all the problems with moving in 3d.

For this 'jetpack' you are essentially balancing your weight between your back and arms. If you get it wrong for a split second, you'll kiss the ground. It's inherently unstable and tiring since you have jet turbines strapped to your arms.

An aircraft is stable. Let go of the controls and it will keep flying.

The closest aircraft comparison would possibly be with a hang glider, except even there your weight is supported and you are essentially just shifting it around.

Many jetpacks in fiction were envisioned to work more like drones. Tell it where to go and it would do the rest. Iron Man would be similar to this thing, except it is described as a fully mechanized suit (plus artificial intelligence), which magically takes care of some of these problems.

Ultimately, 'jetpacks' will probably never exist. There's an inherent physics limitation when trying to strap a whole human body to the side of something small (and generally depicted as being strapped on your back, Bobba Fett style). The center of mass is off.

"There's an inherent physics limitation when trying to strap a whole human body to the side of something small (and generally depicted as being strapped on your back, Bobba Fett style). The center of mass is off."

While obviously wasteful and goofy, there's always the option of putting an upwards-pointing (i.e. pushing down) thruster at the rear of a jetpack like a lever arm.

I was thinking that eventually they could design some kind of powered attachment between the arm pods and the backpack. It would accentuate your desired movement while relieving stress. Maybe they could control it with a Neuralink implant so that there won't be accidental movements due to buffeting. Then if you had that you could build an AI to make it mostly user-error-proof.

To be clear, this is all pie in the sky nonsense, but it's fun to think about. It would still be terribly impractical, but maybe it could be made reliable enough that using it over land would not be immediately fatal to most ordinary people who would want to try it.

“ this is all pie in the sky nonsense”

Nah, only the Neuralink part.

I imagine there will be a whole batch of grifters coming post Neurolink…

Similar to just add it to blockchain.

How about a neurolink to the blockchain? Well I guess we have Doge.

I don't work for neuralink nor do I have any economic stake in their success. Please don't make unjustified accusations of grifting.

> Please don't post insinuations about astroturfing, shilling, bots, brigading, foreign agents and the like.

From the guidelines.

I didn’t accuse you of grifting.

I’m making a prediction of what future grifts will involve.

The stability issues could easily be fixed with more closed-loop control. The much more serious issues are heat and the limited fuel supply.

Agree. This is the same reason why I'm skeptical on flying cars. There's so many fender benders. I don't want a Jetta crashing through my roof.

Sure, general aviation is safer than driving (e.g. less accidents per vehicle, and less accidents per hour/mile), but general aviation is more dangerous than commercial aviation. I suspect there's something going on with maintenance, training, and available safety features. Seems like lowering the barrier of entry to flying is simply going to increase the accident rate because there's just more less skilled people flying.

Of course most flights crash on takeoff and landing, and conceivably that would be automated, so maybe I'm just being paranoid. Still seems impractical, if for no other reason space restrictions on the ground.

GA is actually less safe than driving. It's about as safe as riding a motorcycle: https://inspire.eaa.org/2017/05/11/how-safe-is-it/

GA aircraft crash every day in the US. They don't make the news outside of aviation circles because only 1-2 people are affected. Often the occupants survive.

I'm not a huge fan of those statistics because "deaths per 100k hours" isn't really an appropriate way to compare driving vs. motorcycles vs. GA. If you're comparing driving vs. GA, I think one possible appropriate measure is "deaths per mile"; let's say the average speed of a GA craft is 150mph and the average speed of a car is 37mph, that means that GA is 6 times more deadly than driving a similar distance.

Even that is a flawed measure, however. Few people use GA as a replacement for driving. I think in general, an appropriate measure to use is to estimate the (negative or positive) expected DALYs associated with an activity over a lifetime. That said, this measure does (in my opinion) penalize moderately-unhealthy things worse than very risky activities. For example, BASE jumping has a fatality rate of 0.04% per jump. If you do a handful of crazy BASE jumps, that's only a slight DALY difference - very roughly comparable to not brushing or flossing as far as I can tell from this study [0].

[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4484374/

Commercial aviation gets to pick from the cream of the crop and fully professionalizes it’s pilots - it’s all they do, all the time. That means staying current (keeping habits fresh, remembering key details, etc) happen easier.

Considering how low the frequency is for your your typical GA pilot, it’s honestly a wonder it works as well as it does.

My understanding was that most GA accidents occur in the 50 to 350 flight hours of pilots. By this, perhaps the issue isn't of handpicking the best of the best, but more that they, by definition, survived the early filter.

Getting a basic (entry level) commercial pilot’s license requires 1500 hrs.

What I mean by the ‘cream of the crop’ is you have to be more experienced and pass far greater hurdles (including a far more demanding medical exam) than any GA pilots need to, just to be licensed to try to get hired as a commercial pilot.

It doesn’t mean there aren’t great GA pilots out there - there are! It just means that only the top x percent of GA pilots could pass the requirements to be a commercial pilot.

> Getting a basic (entry level) commercial pilot’s license requires 1500 hrs.

That's not correct. For a US commercial pilot's licence, the hours requirement is 250. It's 1500 hours for an airline transport pilot's licence.

Thank you much! Got my wires crossed apparently.

Applicable FAA Regs btw [https://www.ecfr.gov/current/title-14/chapter-I/subchapter-D...]

Flying is not simple and for everyone - it is complex, but many things are.. and when mastered it is actually not that hard - so disagree, no wonder here.

Flying is easy, flying safely is very difficult. GA inherently allows a great many things that significantly increase risks. Going solo inherently makes you a single point of failure so for example many significant but survivable health issue basically guarantee your death.

And that’s just the start. Pilots run out of fuel, fall asleep, they land on the wrong runway/field, and so forth across lots of very small risks that end up killing people.

I am not saying GA should be more regulated, it’s just important to understand the trade offs in terms of freedom vs safety.

We can also get away with lower GA regulation because there’s relatively few aircraft. If you scaled 1346x to equal the number of automobiles, we’d probably have even more than 1346x accidents, simply because of a self selected pilot skill bias. We’d have to have more regulation then.

Even just 1346x as many accidents is ~1/2 million deaths per year which is unlikely to be considered even remotely acceptable.

I would expect drone like tech so a computer will keep whatever it is easy to steer, drive, and land, and/or just self drive.

That tech doesn't handle mechanical or electrical failures very well. The mishap rate for drones is far higher than for manned aircraft.

And drones don't scale linearly. Small unmanned "toy" drones can get away with RPM control of their props to maintain level flight. RPM control is easy with brushless DC motors and it's mechanically simple. But drones big enough to carry people can't do that (in general) because you cannot change RPM on a big prop nearly as quickly as you can on a small prop, because of inertia. So big props often need collective pitch just like helicopters. Collective pitch is far more mechanically complicated than RPM control and it thus presents more avenues for failure.

The good news is that multirotor drones (even big ones) usually don't need cyclic pitch which is even more complicated than collective pitch, so that makes them less complicated than helicopters, but big drones are still not as mechanically simple as toy drones.

Can't you build an array of smaller (say brushless DC motor) propellers to achieve the same thing? I could have sworn I saw a guy on Youtube do that and hover around his backyard in a home-made frankendrone comprised of a ton of props

You can, and hobbyists have done exactly that. But such aircraft are extremely inefficient and only have enough battery power for a few minutes.

It's kind of like that guy who tied a bunch of little helium balloons to his lawn chair and went flying. It sort of works but it's pointless and dangerous.

Yes, you can certainly do this. But it won't be as efficient because in general large propellers are more efficient than small ones. So your batteries won't last as long.

A closed-loop control system won't fix the stability issues if the pilot's arms are pointed in the wrong direction.

Nonsense, Galvani solved that problem in the 18th century.

Nonsense. It doesn't matter how good your control system is if you can't generate the necessary thrust vector.

It was a joke. Galvani's experiments were on contracting frog muscles with electric currents. The joke being that the jetpack will take control of your muscles.

I wouldn’t be so sure. Fundamentally this is a control input/feedback/positioning/power problem - one we don’t currently know how to model or control in an automated fashion.

With the right mental model and control/power systems, it wouldn’t have to be much different from riding a unicycle. Helicopters have similar issues (it’s a bit like balancing a spinning bowling ball on the end of a stick in practice - yet many people are licensed and safe helicopter pilots)

I’m guessing it’s something that not everyone can do, but something a large percentage of people (20%+?) can do if they spent the time learning and it was systematized usefully.

Minor nitpick. A fixed wing airplane is generally known to be stable. But many other aircraft like multirotor are inherently unstable and require a fast PID loop to stay in the air.

> An aircraft is stable. Let go of the controls and it will keep flying.

That's true for most fixed-wing aircraft, but it's certainly not true for most rotor-wing aircraft. I'd estimate you've got about a second, if you're lucky, between letting go of the cyclic in a Robinson R22 and unrecoverable loss-of-control.

Even with loss of power for rotary wing aircraft don't you have the option to auto rotate to the ground?

The problem with Robinson helicopters specifically (older R-22 & R-44 more than most) is their very low mass rotor system, which results in very low inertia. The time you have to recover is significantly shorter than other high inertia systems on other helicopters.

Their very low cost makes them pretty common for schools and instruction in general, but the low inertia (and resultant fatalities early in its operation) was significant enough that the FAA requires a Robinson specific endorsement.

You have to have enough forward speed. Auto rotation is a joke in a real emergency most of the time.

> Ultimately, 'jetpacks' will probably never exist

So no Aeroball and Harlem Heroes any time soon :(


> since you have jet turbines strapped to your arms

So soldiers that use them would need guns strapped to their feet?

> It's inherently unstable and tiring since you have jet turbines strapped to your arms.

If you look at the photos in the linked article, you'll see that the turbines are on the backpack. It still is tiring for your arms per the article, but for different reasons.

If battery tech continues to improve at current rates then certainly electric jetpacks will be possible and practical, if there's still demand (and we don't destroy ourselves one way or another). Without doing the math though it might be many decades.

Unlikely. The specific energy of jet fuel is more than 40 times that of batteries, and I don't see batteries improving by an order of magnitude. A jetpack would need 40 times more battery mass than fuel to produce the same thrust for the same duration. Of course, the additional weight of the batteries necessitate even more thrust...

Existing aluminum-air batteries have 1300 Wh/kg, or 4.7 MJ/kg in modern units, and it's plausible they could improve to over 20 MJ/kg. The more expensive lithium-air battery already exceeds 6 MJ/kg. Jet fuel is 43 MJ/kg. Pure aluminum is 31 MJ/kg, so to the extent that you can build "new Al-air batteries" during flight with the cathode and electrolyte from "old batteries", you can approach that limit. That sounds ridiculous but we've been doing it with hydrogen-oxygen fuel cells since 01838. Hydrogen has 118 MJ/kg, and there's no fundamental physical reason hydrogen-air fuel cells can't be epsilon above that, though current models are large and heavy.

It's true that all rechargeable batteries like Li-ion batteries are so far under 1 MJ/kg, which more than 40 times worse than jet fuel just as you say, but it's extremely plausible that Al-air could beat Li-ion by an order of magnitude, and Li-air already does, except for the best Li-ion cells. It's already most of the way there. And fuel cells can beat jet fuel by almost a factor of 3, and for low-power applications they do.

Betavoltaic cells and TEGs have even higher energy density but you can't turn them off, so you need to dissipate the power they produce when you're not using it to fly or whatever. You could build a hybrid system with a large glide ratio that uses chemical batteries for takeoff and a betavoltaic battery or TEG for long-distance cruising, but you might have to only land it on water to keep it from overheating while it was on the ground.




As you say, practicable batteries in production have specific energy under 300 Wh/kg (1 MJ/kg), 40x worse than fuel.

The other technologies you mention don't seem to be practical for now. I don't think it is reasonable to expect any breakthrough making it to market in the next decade. With specific energy doubling every 10+ yrs, electric flight might be sensible for niche applications (training flights, occasional urban transport for example to the airport) in a few years, but for anything else it'll be several decades realistically.

Hydrogen-air fuel cells and aluminum-air batteries don't need any breakthroughs to work; they're well-understood, proven technology. They're just more expensive than kerosene and, in the case of hydrogen, more voluminous.

To put it differently, the reason nobody is flying across the country today on aluminum-air battery power is not that the existing batteries don't have the range; it's that they can fly across the country more cheaply on a combustion-powered jet.

(I think that will continue to be the case even when the combustion fuel is synthesized with electrical energy.)

Nailed it.

Even in cars where there they do a bunch of gliding (rolling) batteries are just becoming plausible (looking back over time).

> If battery tech continues to improve at current rates

What do you consider current rates? They improve slowly, maybe 3-7% a year. Last I looked, batteries are so much worse in terms of specific energy than fossile fuels that we're looking at several decades before electric flight becomes practicable (except for very short distances and training flights).

7% a year means doubling every decade, 3% means doubling every two. Fossil fuel efficiency isn't moving at nearly that rate.

If current rates continue, battery powered jetpacks should be compelling within 60-120 years

I feel like you could describe cars the same way:

You've got two axis of movement at 60mph. Stray a couple feet left or right and you die in fiery inferno. Stop too fast or too slow, same deal. Maybe appropriate for highly-trained specialists, not for every-man's garage.

My point is not that "cars are death machines no one should own," although there are certainly those who hold that opinion. Rather that inherently dangerous things can be made relatively safe with enough systems around them: roads, signs, traffic laws, licenses, seatbelts, and so on.

Actually, the high level question in here is quite interesting (and has even been discussed in some sci-fi).

Humans evolutionarily think about movement with a 2 dimensional mindset because for much of our history we only needed to think about 2d movement. It's why even modern flight is centered around the idea of stacking multiple 2d environments (via elevation / flight levels) and then just ignoring that 3rd dimension for the most part.

This is why something like a car is operationally intuitive -- humans don't need training to quickly pick up the interface for one, even a kid could operate a 2d vehicle. The systems around them mainly manage the risk around _conflict_ introduced by having multiple actors.

This is also where a plane (or submarine, or jetpack) is fundamentally different. The systems around those need to manage not only conflict but also our sensory deficiencies. It's very easy to get disoriented in 3d movement (it's very easy to lose the ability to tell up from down) and there have been plenty of plane crashes due to this. That's why pilots need to infer their orientation from instruments rather than just their senses. That's also why flying cars and jetpacks are not widely available -- the amount of training just to operate such devices _alone_ is already very high, let alone having to manage conflict in addition to that.

Cars are mostly 1d vehicles in practice, unless they are bumper cars. We try really hard to minimize 2d interactions between cars by stacking multiple 1d environments (lanes) and ignoring the 2nd dimension for the most part. Where we cannot ignore it we try to make it safe by adding turn lanes, roundabouts, traffic lights or building interchanges.

Quite true. Which really says a lot about what we don't want in transportation --- more degrees of freedom.

Teleportation tubes on the other hand...

>It's why even modern flight is centered around the idea of stacking multiple 2d environments (via elevation / flight levels) and then just ignoring that 3rd dimension for the most part.

Generally you want to fly at a constant altitude because climbing and descending require energy transfers. Humans have little trouble coping with the concept of 3-dimensional flight, indicated by the enduring popularity of combat flight simulators, but aircraft that aren't built for combat physically struggle (and even in those that are, such flight demands careful energy management).

The answer here is what we have in drones. Drones can stay perfectly still in the air now. A flying car or personal "jet pack" would be the same. The usable system would provide all the stabilization of a drone and your controls would be just that of a car, with a separate setting for altitude.

And just like cars, you wouldn't be flying it randomly, we'd have to build "lanes" at different heights, etc. You don't drive your car randomly through buildings. In fact, connecting to a network and having it fly for you would be the most likely scenario.

Not to say that there wouldn't be "free flight" parks around.

> It's why even modern flight is centered around the idea of stacking multiple 2d environments

That's for sharing the space. It's not only a set of stacked 2D environments, those are also divided in road-like spaces, with a limited number of junctions.

You raise some interesting points here that I had not previously considered with respect to flight/submarines vs. land vehicles/boats. That third dimension must introduce a lot of cognitive load, even before conflict of other vessels/aircraft enter the scene.

There's some sci-fi (that I cannot remember off the top of my head) that actually uses this as a plot point.

I may be misremembering, but the idea is there's a special race of humans who have continued to evolve living in low gravity (space) environment, and the terrestrial human (those living on planets) governments would hire them as space mercenaries because they're at a huge advantage when it comes to 3d combat compared to training some terrestrial guy.

Ender's game; maybe not what you're referring to (based on your description), and also uses 3d navigation as a plot point ('The enemy is down')

This was a limitation of Khan in the second Star Trek film.

There is a trilogy of books written covering Khan's life and it very subtly shows why Khan has this difficulty, but never points at it and shouts.

I had always thought of that line as metaphorical (“two dimensional thinking”), but that’s a very interesting idea, and fits well with the final battle that immediately follows it.

You don't mean The Expanse, do you?

> Humans evolutionarily think about movement with a 2 dimensional mindset because for much of our history we only needed to think about 2d movement.

That might depend on whether the aquatic ape hypothesis is true ;)

More seriously, in addition to diving and climbing, humans have been using throwing weapons for hundreds of thousands of years -- not the same as navigating one's body through 3 dimensions, but it still requires a 3 dimensional mindset because you need to work out where the trajectories will intersect with something traveling in a different plane of movement. So I'd be curious how much hard evidence there actually is for human deficiencies in 3 dimensional thinking compared to say dolphins or parrots.

> Humans evolutionarily think about movement with a 2 dimensional mindset

The humans evolved to brachiate for a lot longer than they've been wandering around savannas.

> even a kid could operate a 2d vehicle.

Trying this was a mistake and nearly got me killed. Twice.

Planes and submarines treat down as special because down is genuinely special. We would have some other abstraction if this were not the case.

It _is_ special but we cannot perceive it correctly. We do not have an absolute sense of "down" (and our absolute sense of "forward" and "backward" are based on a assuming fixed "down").

We sense "down" based on assuming that 1G of acceleration is the "down" position. This is fine if you're stationary. This is fine if you're moving in 2d. But accelerate in 3d and all of a sudden you can get completely disoriented because the "down" you're latching on to could be any acceleration vector.

We _can_ manage this, but it is an acquired skill and we need instruments to help us. Pilots (and especially fighter pilots or astronauts who truly experience a lot of 3d acceleration) need to train for years to acquire this skill.

Can you imagine training an average person years just to _use_ a jetpack? That's why we have jetpacks and yet most people don't care.

Most of the astronaut and pilot training on this, btw, is to completely ignore what our internal intuition is and use instruments and direct math - for the reason you’re talking about, but also because especially at the astronaut level ALL intuition related to speed, direction, etc. is generally wrong. for pilots it’s often only mostly wrong, but using intuition and flying IFR is not going to work for long.

For an astronaut in orbit, going ‘up’ means accelerating. Going ‘down’ means slowing down. Going sideways (in the way we typically think of it) involves changing velocity in least 2 vectors twice, etc.

They have the pointy bits forward AND treat down as a problem as well. Gravity applies equally to Roombas and Cessnas and Soyuz, but only one of those is built on planar symmetry rather than radial symmetry. Don't you agree with that and isn't that interesting, that humans seems to have something about having a forward facing Cartesian plane.

> there have been plenty of plane crashes due to this

JFK jr

The jargon term for this is spacial disorientation.

> Humans evolutionarily think about movement with a 2 dimensional mindset because for much of our history we only needed to think about 2d movement.

Citation required? If you hang out with a child you quickly discover that their world is quite three dimensional. Heck, climbing is a fast growing sport. Again, three dimensional. We're made to run, jump, and climb. Three dimensional.

From NASA: https://www.nasa.gov/audience/forstudents/9-12/features/F_Hu...

"When there is no visual input as is common in many flight situations, we rely more heavily on our vestibular sense for this information. However, in flight and in space, our vestibular system, _which is designed to work on the ground in a 1g environment_, often provides us with erroneous or disorienting information."

We have a system to somewhat understand and orient ourselves in 3d obviously, but it has quirks because evolution tuned it to work best on the ground + assuming 1G of gravity as "down".

Orienting in 3d is not intuitive for us. We can do it but we need a _lot_ of help to do it safely.

Your quote talks about 1g gravity not that 3d is not intuitive. A 3d world with 1g could be intuitive.

> __on the ground__ in a 1g

Kids don't act in true 3-D, they act in Doom-like 2-D. It gives the appearance of 3-D, but the Z-axis is barely off zero. Climbing swaps X and Z, but is still 2-D.

If it helps, think of what everybody else is calling "3-D" as "no obvious primary axis."

Climbing is two-dimensional, not three - on any given part of a wall or tree, you can move left-right and up-down but not in-out.

1) People, especially kids, jump between and across structures all the time.

2) Humans are great at throwing and catching objects, even with complex, changing trajectories--bouncing off walls, etc.

3) We have two innate senses that are clearly adapted to 3 dimensions: stereoscopic vision and proprioception.

What makes those behaviors relatively intuitive is constant acceleration. In a sense constant acceleration makes everything 2D. (Or 2.5D?) When humans need to track objects which independently accelerate along 3 axes, then there's a much stronger case for an environment alien to humans. (Counter point: hunting birds, though I believe hunters prefer to take their shot when birds are beginning or ending their flight. But notably the most salient characteristic there is acceleration, not merely relative movement in 3D space.)

Yeah, the more that I think about it, you get much more predictive power by emphasizing acceleration, not spatial dimensionality. And I don't think that's being pedantic; the distinction matters. When you look at studies of how the brain processes motion, constant acceleration (at least along 2 of 3 axes, unless/until hitting another object) is often one of the key assumptions that seems to be built into our cognition.

For example, tracking many objects moving independently in 3D space is pretty darned difficult for humans.[citation needed] But that probably has more to do with relative motion (and thus relative acceleration) than with the number of dimensions as a human can track two such objects surprisingly well, especially if they have a third, fixed reference independent from themselves.

Would be curious to compare & contrast studies of spatial cognition between marine animals and terrestrial animals, though.

Love this framing. Feels like the three body problem is relevant.

I've worked for several years with children, and have also piloted aircraft. 3D is _tough_, at least for me.

>Heck, climbing is a fast growing sport. Again, three dimensional.

Ummm… no? The surface of a mountain is still two dimensional.

A mountain surface is 2.5 dimensional. If you allow for the fractal part.

The third axis adds the risk of a gravity impact to every accident. Maybe it's solvable with some kind of failproof parachute system, I dunno. I wouldn't invest in it.

Showing that cars are scary doesn't disprove that flying cars are more scary

Jetpacks don't have brakes. Once you start moving, coming to a stop is very difficult or very harmful. You have to be a highly trained specialist to operate a jetpack at all, while you can gently learn to operate a car.

Flight in general is unforgiving this way. There's only so much practicing you can do under 20 ft and 20 mph.

Airplanes you can at least use simulators and flight instructors who can take control when you mess up; jetpacks you lose any opportunity for a co-pilot, so you probably need good flight simulators you can log hundreds of hours in before strapping in.

I think this comment is reasonable and the replies to this comment are filled with bad takes.

Currently designed Jetpacks don't have brakes, or any safety features really, but that's just a lack of development.

You could easily think of hundreds of safety features that would make Jetpacks in a distant future seem pretty safe, from auto pilot/recovery features, automated object detection and avoidance, body suits with built in airbags, better designed packs that give things like 100x better articulation control, built in parachutes, the list could go on forever really.

Meanwhile cars actually have additional dangerous properties: being stuck in very confined tracks where any other user errors affect you, limited visibility, and a massive amount of heavy metal surrounding you.

I don't see why Jetpacks couldn't be as safe as a cars given they had an equal amount of investment into safety as we see modern cars. And to answer the article as to why they aren't popular, it's pretty easy to see that they just kind of suck as they are now, they need improvements in nearly every dimension.

I think there are a couple of key differences that you’re underplaying.

First, for usage of cars in society, there’s a nice gradual curve where an early slow unreliable car is still somewhat useful, and a faster car is a bit more useful, etc, and that’s what allowed them to get off the ground (as it were). There’s a vastly higher threshold before jetpacks start being usable and useful.

Second, cars are relatively fail-safe in that if you take your foot off the accelerator the car will coast to a halt. Lots of cars can easily come to a safe stop together -- traffic jams are bad but not immediately life-threatening.

Jetpacks aren’t nearly as failsafe because if you stop flying you need to land (or more likely, crash-land).

Planes have the same two advantages over jetpacks, because even a slow or unreliable plane is useful because it can carry cargo; and most planes can glide a bit which helps reduce the risk of crash landings.

Apart from anything else, the minimum viable car was pretty much as safe as modern cars (probably actually harder to kill yourself in the original car with its 10mph top speed), and just as intuitive to operate safely. The safety advances came later to deal mostly with problems which arose later (speed and other cars and boredom from long distance low effort driving)

The reason they are not popular is that we don't have a practical power source. Flight times are measured in minutes. And practical ones that could be used by anyone would be much larger (think VTOL hang glider, not Bobba Fett).

Even with a practical power source, you know have an immense amount of energy stored right next to your body. You need to be able to direct said energy in a safe way. Good luck.

There's only so much airbags can do. Imagine where you would locate those airbags. Cant be pressed against the body either (airbags can cause horrible injuries). Parachutes won't help close to the ground.

yes but the way to make cars safe is to - seriously constrain their movements (all cars here move in this direction, you can get off here, you can get on here etc. ), have different types of licenses for different kinds of cars, and limit their speeds based on location.

Jetpacks, and the flying car, have more possible ways to move.

The Jetsons used to show the flying car working the way the normal car did - highways in the sky - that's basically the way it would have to work to be made safe, as long as there are any sizable amount of users of the jetpack or flying car.

The jetpack has of course other hazards associated with it such as the engine being really close to the human operating it with significantly less shielding than one has on the car.

on edit: I think there might have been problems with the car in some Jetsons and George had to parachute to safety, arms crossed and a seriously miffed expression on his face.

So all that said - what would be required of the flying car for it to work well enough to supplant the car? (not the jetpack, that will at best be the skateboard of the sky)

1. It would have to be significantly faster, able to go longer (makes sense this would be the case because obviously you can fly quicker than you can drive so I assume this benefit will be a gimme, but it has to be significant for people to care. If you can make the flight to grandma's house in 3 hours instead of 8 there would be interest)

2. It would have to not cost very much more to own or to run.

3. It would have to not be any less safe for drivers than it currently is to drive - at the beginning this might be the case because less drivers means more safe maybe.

4. there would probably have to be significant safety features built in to keep flying cars from causing catastrophic damage if they failed - this seems to right there make it impossible because it has to not cost much more than a normal car.

5. There would probably have to increase in automation of cars to be able to detect when something wrong, when someone breaking flight rules etc.

6. no internal combustion engine flying cars, because a falling car with internal combustion engine is also a potential bomb.

so what are the benefits - we've already mentioned 1 but are there others?

Conceivably with a mass movement to flying cars instead of cars the infrastructure of cars would no longer be needed or need to be maintained. A utopian vision would then be that all that land that is currently big packed freeways get converted to parks etc. although a cynical vision would say oh nobody would want to pay for that and they turn into dystopian hellholes and kids go there to get eaten by coyotes.

Possible benefit #3 - to make safe have to have much routes for everything but given that we have all the sky conceivably there could be more routes, including emergency routes that would be left to emergency services or people registered for a possible quick route (quick routes to hospital for birth etc.) All of this of course implies flying cars with effective computer surveillance of drivers.

So I see these benefits to flying car - 1. quicker longer trips enabled. 2. No longer need driving car infrastructure 3. possible solutions to congestion are still available with flying car.

But does that mean it is doable.

I think the needed functionality points basically cancels out it ever working but maybe I am pessimistic, although I do think that now we are actually getting to the point where the necessary prerequisites for flying cars are starting to be built - specifically good electric cars and driving automation and services (but way early for that, flying cars in 100 years at this rate)

Drivable aircraft would need to be more convenient than cars.

Does anyone do a pre-drive walk-around and engine test of their car, or do they just turn it on and go? If you're in a city do you request permission to begin a trip from a DMV controller via local frequencies, or just go wherever? Does every home have a runway or just a driveway?

These aren't insurmountable challenges but there are chasms on the way from possible to safe to convenient.

(Also to your point 6, I'd add to the Kzinti lesson: any energy storage device is a weapon effective in proportion to its stored power—gas tank, flywheel, Li+ battery, dammed hydro, you name it.)

I feel somewhat in the middle between both of your opinions.

The "average joe" in some regions may not fly regularly, but around here there's many farmers with Cessnas that do routine work.

Currently, if you have a use for it and are somewhat competent, it's practical to fly and not out of reach for the common man.

But in no near future do I see them reducing the restrictions, flight hours, air traffic protocols, etc.

That being said, I don't see much practicality for a jetpack other than sport or rescue.

That's a big part of my reasoning, there are some fundamental impracticalities to personal aviation that limit it to particularly niche use cases. Those don't really change just because it's a flying car or jetpack.

I can of course picture a world where there are automated skyways, and electric AVs guide themeselves from abode to shopping mall airport, I'm not without imagination. But I'm not hopeful.

The big difference is that cars have brakes and that coming to a full stop will avoid most crashes.

There is no good "emergency braking" for jetpacks, there is not even "autorotation" as there is for helicopters.

I think maybe the problems are: 1) the extra axis of movement means more operating complexity, and 2) there is no equivalent of "5 mph in a parking lot" on a jetpack, either you're flying or you're not.

> inherently dangerous things can be made relatively safe with enough systems around them: roads, signs, traffic laws, licenses, seatbelts, and so on.

While this is true, the issue is that what is required for "enough" can vary very widely. In particular, what would be "enough" for jetpacks (and flying machines more generally) is a lot more than what experience has shown to be "enough" for cars. Some indications of why that is are the frequency of airplane accidents involving experienced pilots, who have had a lot more training on how to fly a plane than anyone gets on how to drive a car, and also the amount of time and effort and the level of continuing human supervision required to keep commercial air travel as safe as it is, even though that also involves experienced pilots and has the support of many complex systems.

It's not really a "new frontier being misunderstood" though, it's very clear what it's value proposition is, and it's also clear from our history with aviation so far, what the challenges are. As I said in another comment, we don't even trust people to fly small drones without certification and FAA regulation, there's good reason for that, being in the air is nothing like being on a road.

To answer your question-- people in the past were expecting what has happened with small drones. Namely, that there'd be a metric fuckton of them, and that regulators would have to scramble to keep order before angry townsfolk began firing their rifles up at in the sky at them.

Yeah, people in the past overestimate how eager people are to take obvious risks.

To be fair, the eagerness of people to do activities that feel risky but actually aren't makes that prediction harder than it looks at first.

> we don't even trust people to fly small drones without certification and FAA regulation, there's good reason for that, being in the air is nothing like being on a road.

We don't trust people to operate cars on a road without DMV certification, FMVSS regulations, and a substantial amount of liability insurance.

Your engine dies while driving, nothing happens.

Your engine dies while flying, good luck, pal.

> Your engine dies while flying, good luck, pal.

In a jetpack, yes. Good luck. Drone, good luck too.

Airplane? You glide down.

Helicopter? You autorotate down.

If only we had an invention that used air resistance to slow falls...

Do parachutes help when you lose control 50ft off the ground? Deploy time is probably too short. Also lateral speed may be fatal enough with a jetpack.

Rocket deployed parachute. Kinda like https://en.wikipedia.org/wiki/Cirrus_Airframe_Parachute_Syst...

Speeds up deploy time by making the deploy happen, instead of waiting for gravity/airflow to deploy it.

Still needs a certain minimum height to be effective, >= 400 ft in straight and level flight, 920 ft in a spin [1]. Don't think it would be much use in a jetpack (apart from the fact that the article states that they haven't found a way yet to attach both a jetpack and a parachute, let alone a ballistic one).

[1] https://cirrusaircraft.com/wp-content/uploads/2014/12/CAPS_G...

Body airbags or similar would likely work for lower altitude.

Parachutes don’t work well enough for this hypothetical.

Are there full body airbags? Could that even work?

Yes, that will work. It's how Spirit and Opportunity landed on Mars. Many people will die in airbag deployment failures before it works reliably, some of whom would have survived without the airbags, and they will be prohibited in the sort of repressive jurisdictions that prohibit bulletproof vests and gas masks.

> Yes, that will work. It's how Spirit and Opportunity landed on Mars.

What do you know that makes you say "that will work"? A planned and controlled landing for a rover (engineered from metal and stuff) on a planet with a gravity 38% that of earth is rather different from this hypothetical emergency system for fragile humans on earth.

Ask me again in 50 years. Or do the math.

Ok, let's do the math. The result is easy: When you fall from h meters (accelerating), and then decelerate over s meters cushion, your deceleration is (if it is nice and uniform) h/s. So, when you want to decelerate with at most 5g, your cushion needs to be 1/5th of the free fall distance.

For example: Velocity from a 100 metre (300 ft) free fall is v = sqrt(2gh) = 44 m/s = 160 km/h = 100 mph.

Now let's say we might survive 5g to 50g (Astronauts pull 5g routinely, Lady Di in her car crash had about 70g).

So, to brake a fall from 100m somewhat comfortably, you need a 20m cushion. To brake it such that you have a small chance of survival, you need at least a 2m cushion. This scales linearly with height you fall from, until you approach terminal velocity.

Interestingly, terminal velocity is around 200 to 300 km/h (depending on position), or 125 to 185 mph, or 54 to 80 m/s, requiring a 3m to 30m cushion.

A 30m airbag in a jetpack strikes me as unlikely. A 2m airbag in a jetpack that achieves constant deceleration may be feasible, though not soon, and certainly not something I want to experience.

For reference, these Fall-Pac units at 1.2 metres cushion promise fall protection up to 3-5 metres.


Yup, but the situation is even better than that!

https://en.wikipedia.org/wiki/John_Stapp#Work_on_effects_of_... shows that 50 gees is survivable, at which speed you need 120 ms and 3.6 m to decelerate from 60 m/s. Not pleasant but still safer than a car crash. If the airbags inflate before you hit the ground your terminal velocity is much lower, decreasing roughly in inverse proportion to your hydraulic diameter (√(2mg/ρ/A/Cd)), so a 1.5-meter-radius cocoon of airbags around you will cut your terminal velocity to about 20 m/s, at which point you need 40 ms and 400 mm to stop safely. For this you need something like 4-12 1.5-meter-diameter airbags, 7 m² of surface each; at 20-μm thickness that's 140 cc, and if it's mostly something like gel-spun UHMWPE fiber or polyimide film, it's also about 140 g each, so 0.5-1.7 kg total bag weight --- plus conventionally 2 kg of nitrogen per airbag in the form of 3 kg of sodium azide, which is another excellent reason to perform the inflation well before you hit the ground, so you can use atmospheric air instead.

Suppose you weigh 100 kg. To stop you at a safe 20 gees max when you hit, the bag needs to exert 2000 kg max force or 20 kN, so the pressure in a bag acting over something like 1 m² of your body needs to peak at 20 kPa, about 0.2 atmospheres or 2.8 psi. Approximating hoop stress as ½Pr/t we get a bit under 400 MPa stress in the bag, too much for unaided polyimide but an order of magnitude lower than what UHMWPE fiber can handle. So you can make the bag thinner than that, lowering the weight further, perhaps to 40 g per airbag. There are whiplash shock loading problems conventionally handled in automotive airbags by generous safety factors that can be reduced by origami design and judicious addition of thicker compliant material like nylon.

A 30m airbag would need to be 20x thicker and would have 400x as much area, so it would weigh 8000x as much, 320 kg. This would indeed be unwieldy for a backpack.

You can closely approximate constant deceleration by connecting the airbag under you with other, more voluminous airbags on the other side of you, just as a car tire closely approximates constant pressure when traveling over bumps in the road. But it's not necessary; what's necessary is acceptable peak deceleration and, probably, minimal jerk. It's true that constant deceleration is the best case of minimal distance and time for a given peak deceleration, but even linearly increasing deceleration, like from a Hookean spring, only doubles the time needed to stop when holding the peak deceleration constant, thus multiplying the distance by √2.

So, you see, all the materials and mechanisms necessary are already available, though only in the last few decades. There's no technical risk. It's "just" a question of engineering the thing to not kill people all the time when it fails, based on experience with what the deadly failure modes are. It'll require a lot of work and many deaths, but if people put in the work, it will definitely work.

Let me know if I got any of the calculations wrong!

> Are there full body airbags? Could that even work?

Let me know if you find out. I have got to get one :-)

There is this urban airbag for cyclists, but it protects "only" the head...



I was picturing a massive bubble with me in the middle so I could jump off the roof and bounce away or something...

Those are nice, but I have a feeling if I jumped off the roof in one, I might still break a few ribs!

If only that invention wasn't supposed to be strapped to the same part of the person's anatomy as the jetpack, with the result being that no practically working implementation combining the two exists...

That's not an intractable problem by a mile.

It's also not the solved problem your snark implied. I mean, someone's been working on it for decades and his solution is fly over water as much as possible!

(As other posters have alluded to, parachutes won't save you at low altitudes. In the mean time, it's further weight on your back on a device which is already difficult to control, and not really optimal for releasing next to jets of hot kerosene either)

Tens of person-years of work is not as much investment as you are implying in the context of manned heavier-than-air flight. Boeing spends ten person-years on developing flight every 40 minutes on average. Since you wrote your comment 4 hours ago Boeing has spent about 60 person-years on developing flight.

I think it was a mistake to allow just about anyone behind the wheel of a car. It results in upwards of 1 million deaths per year, that's more than malaria. And that's not including deaths attributed to air pollution.


This analogy doesn't really work because car are inherently much much safer than jetpacks just by the virtue of the fact that an error or failure or accident is almost not fatal. 0.7 percent of car accidents are fatal. In serious plane accidents, what laypersons would call crashes, the fatality rate is about 55%. Which is actually not bad considering, but not imagine if a plane was instead not this highly regulated bus-like thing that makes set routes and piloted by only experts, but something anyone can buy and fly like a hypothetical consumer jetpack. How many jetpack accidents are something that don't result in dismemberment or death? It must be a low number.

From a safety perspective, you're going to be in a little bit of trouble because this hypothetical industry will have profiteers and customers that simply won't let you regular them much. Cars are a special case because nearly everyone rides in them so safety concerns (thank you Ralph Nader) are politically easy and the capital owning class have a hard time pushing back on stories of dead families in terrible accidents. The capital owning class finds it easy to push back against regulations on motorcycles, thus maximizing their profit, because even people into motorcycles don't want crumple-zones, roll-cages, big flashing lights, bumpers, etc because it hurts the aesthetic and experience they buy motorcycles for. Lets remember it took 60-70 years of motorcycle popularity before helmet laws got popular. That's a very slow regulatory burn.

So the jetpack is a lot more like a motorcycle. Even on well regulated roads full of safety devices they're still death traps because any vehicle without a "cage" is simply dangerous and impossible to be made safe. The NHTSA: For every mile traveled, motorcyclists have a risk of a fatal accident that is 35 times higher than a car driver.

So no, you probably can't car-ize a jetpack because a jetpack isn't a car. Its own unique mode of transportation and one without a cage and something inherently unstable. I imagine your best case scenario is many times the risk of motorcycles. This is why investors, the living arm of capitalism, refuse to mass-fund these deathtraps, but they'll fund any gimmicky crypto or social media thing. I don't think a successful jetpack company wouldn't want to car-ize it anyway. It would take away the appeal and the profit incentive would demand they continue to make them as sexily dangerous and performative as they can get away with to increase that appeal, thus sales.

You also have the larger regulatory and public safety issues drones have. They can't stay aloft without power and come crashing down without wings or autogyration to helps them down. So in populated areas it would be irresponsible to have these flying over the heads of people.

If you have free time, go ahead and visit /r/weirdwings or /r/weirdwheels. There's no shortage of "innovative" death-traps out there that failed to penetrate the market because they're just too dangerous.

Last but not least, single-person transportation tends to be the kiss of death anyway from both a practicality and cost perspective. People are social, have significant others, children, elderly to take care of, etc so the single-person vehicle has to be something you own ON TOP of owning a car or two. It doesn't replace cars, so a prospective buyer is someone who has to make car payments as well as jetpack payments. What percent of Americans can afford this vs people who can afford cars and the occasional airline ticket? Currently, an affordable jetpack is $200,000. If through the miracle of mass production you get that down to 1/2 or 1/3rd that, its still the cost of an expensive luxury car. What market are you appealing to even if you iron out some of the safety issues? Who is this unicorn who can afford this and would want it, especially considering the wealthy tend to be old men unfit to pilot something like this safely and with comfort, the same way the average Corvette driver isn't hot 20 something guys like in the movies, but older men close to retirement.

Google says the average age of a corvette owner is 61. Do you really want 61 year olds flying over your head in Iron Man cosplay that actually flies? Knowing full well if their arm muscles give out then their vector radically changes and more or less turns them into 70+mph human missiles aiming for the ground?

In a country that has traded efficient public transportation like intra-city light rail, trollies, and fast regional links for car culture, well, you're kinda stuck making car payments then. Not enough people can spend $100,000 on a jetpack the same way we all don't have a Cessna waiting for us as the local regional airport. The money ain't here even if you can fix safety and the absurdly low flight time of just a few minutes. The sci-fi fantasy of flying alone above a city is not only technically difficult, ridiculously dangerous, but economically impossible for all put the wealthiest.

Someday, helicopters will operate like video games, due to complete flight software stabilization and abstraction of the horrifically complicated control surfaces. This is already starting. But uptake is slow[1]

At that time, we can revisit jetpacks and use onboard software to completely abstract the horrifically complicated control problem.

1. https://aviation.stackexchange.com/questions/23977/why-arent...

There are at least a couple of rotary wing UAVs like the K-Max and Fire Scout that are just retrofitted conventional airframes. So in a way it's almost like the technology skipped manned flight and was put directly into unmanned aircraft first. Perhaps we'll see some of it trickle back down as it becomes a more proven technology.

Personally I think the form that "jet packs" will eventually take is just an electric multicopter that you strap into somehow.

I agree and it's pretty incredible, but I think to enable popularization of it as personal transport you'd need to abstract the pilot away entirely. Automate the whole journey, from a system that's aware of all other journeys. That still can't account for all dangers, but at least people wouldn't be flying into each other at 100mph

At 25k USD for the cheapest helicoper blade, I don't see them getting more popular even if they become trivial to fly.

Tiny jet turbines are expensive too.

Wouldn't mass manufacturing significantly drive these costs down ? Fuel costs however...

> They're still aircraft after all, at the very least you're going to need pilots license.

I think a reasonable interpretation of the promise of jetpacks would be more like the "ultralight vehicles" category (as it's called in the United States). These vehicles require no registration or pilot certification. Some are fairly traditional rigid airplane designs (just very small and lightweight), but the category also includes powered paragliders (AKA paramotors) and some of the smaller powered parachutes.

Where I grew up in the US these were fairly common to see in the air, and no one thought it was odd that they didn't require a pilots license. Perhaps for many people in many areas the regulations or different, and it strikes them as absurd to fly aircraft without a license?

Ironically where I live, it's far simpler to get a private pilot's license than a provisional car license.

It takes 25 hour in a plane to get a recreational license, and 120 supervised hours logged in a car, for people who don't have a relative to do the supervision and need to pay and instructor, the cost comes out more than getting a pilots license.

Once that's done to be allowed on the road alone, they need to get their 2nd provisional license a year later, then full car license a year again after that, with additional tests along the way.

> They're still aircraft after all, at the very least you're going to need pilots license.

The FAA is amenable to allowing people to operate small personal for non-commercial purposes without a license. If you do not take passengers and do not operate it in time, place, and manner that creates a hazard for others, there's a very real "if you kill your own damn self that's your problem" regulatory mentality.

What you actually need a license for is to exceed speed/weight/fuel limitations designed to ensure these conditions. If you're going for a part 103 ultralight craft, that's 55 knots / 254 pounds / 5 gallons of fuel. Might be hard to design a usable jetpack under these constraints.

>> There's no "bicycle" of jetpacks

Grab any drone with a 200kg capacity (they do exist), hang a lawn chair under it, and take to the sky. That's probably safer. Jetpacks as a concept might get overtaken by the small helicopters we today call drones.

Funny you mention that. I just saw the below on reddit the other day.


That's a nice piece of hardware.

There are other big, people-carrying drones. eHang was probably the first, in 2016. They've actually sold a few. Price is above US$300K. They routinely fly above cities. Like everybody else, they're battery-limited. Their limit is about 30 minutes.

All those un-shrouded spinning blades at low height are worrisome.

eHang was not the first, but they do seem to have good marketing.

German company Volocopter flew a manned demonstration rig in 2011 (the famous pilates ball [1]), and had the first manned flight of the Volocopter multicopter (certified, 18 rotors) in February 2016, with the CEO himself flying [2].

I don't know when the eHang 184 flew first (a video on youtube says Feb 2018 [3]). Personally, I find the design (with 8 rotors in a quadratic arrangement at knee-height, perfect for decapitating pedestrians) atrocious. (The Volocopter blades are above the cabin, as in a helicopter.)

And where do you get the 30 minutes endurance for the eHang from? When I divide the range by the cruise speed from Wikipedia, I get about 8 minutes endurance.

[1] https://www.youtube.com/watch?v=L75ESD9PBOw

[2] https://www.youtube.com/watch?v=OazFiIhwAEs

[3] https://www.youtube.com/watch?v=Mr1V-r2YxME

Put a giant pre-inflated airbag around it and that might not be unreasonable.

But would you let a child operate the drone chair? I think you're right that drones would be some kind of safer, I think it's the more likely of the two technologies to work for personal aviation.

If you want to get to work in the morning, then a drone full of autopilots and AI is the safe and reliable way to fly across the city. But for living the Ironman fantasy of sailing through windows then you'll need a jetpack with all the associated dangers.

To be completely honest my expectations of jet packs were modeled by cartoons.

I am admitting this publicly as a reminder to myself and others for the fact that for the public, the process of writing software is modeled by scenes of hackers in Hollywood movies.

> What were we expecting from jetpacks though, really?

Drones, in the form of a jetpack.

A little joystick in each hand with DJI levels of KISS, and with the same DJI "Help I'm out of control!" button too. Probably "return to home" too.

We don't/can't have that, because there's no servo-mechanical joints to be controlled in the referenced rocket pack system.

I feel that improved control systems could go a long way to making them more controllable. Look at RC aircraft, they used to take a lot of practice to fly and even when mastered required so much focus that they weren't useful for anything. But now drones practically fly themselves and instead of "flying" the drone, the pilot really just tells it where to go. The flight software figures out the rest.

There's no reason the same principles can't be applied to jet packs. Add a gyro or two, gps etc to give it the data it needs and the pilot should have a much easier time.

The more difficult to solve problem is with endurance. They are only good for 10s of seconds of powered flight.

I think the part that's missing (besides the knowledge and understanding of the operation in the airspace) is enough (automatic) assistance that its manipulation can be done by someone with the sake skills that any GA pilot could have.

>There's no "bicycle" of jetpacks, you've got three axis of movement and certain death in every direction but up, it's just not a tool that belongs in the every-man's garage.

There is a perfectly good flying vehicle that can be flown by an ordinary person with a reasonable amount of training; it's called a powered paraglider. However, it has the disadvantage that it is very large, and if the weather is not favorable, you can't fly.

The analogy with a car would be "road sometimes spontaneously turns into scree", and it would be very hard to design a car that can cope with that.

I think we probably expected something closer to a motorcycle as far as danger and accessibility.

And yet, it’s quite easy to fly a drone in simple mannerisms. The UX failure of the jet pack is refinement in software, which drone makers have already figured out.

The real issue is, with an 8 minute flight time, it’s good for demonstrations and that’s it.

The DJI drones have really good stabilization and crash prevention.

Of course it’s different with a human involved, but scale up the mavic pro to hold 200 lbs, do a few more iterations, load in a Tesla battery and we’re there.

> There's no "bicycle" of jetpacks, you've got three axis of movement and certain death in every direction but up,

Arguably, this could exist, and is a self-stabilizing battery powered drone.

> What were we expecting from jetpacks though, really?

The reality turns out to be different, but, I'd say we were expecting practical personal flight, as seen in video games with jetpacks.

> What were we expecting from jetpacks though, really?

Something easy-ish to use and safe.

Yeah, probably unrealistic, but nevertheless.

>certain death in every direction but up

Up is also certain death, if you're not carrying bottled oxygen.

I think we expect of them full self driving from the get go.

You could say the same of regular cars, I would argue.

I donno the mandolorian maybe?!

rocket man.

Exactly, right there in the article theres a highlighted quote mentioning this:

> Now, the flight duration is too short, and the degree of difficulty too great. But this was also the case for the Wright brothers

I think the next step for Jetpacks is to develop automated navigation/stabilization systems. We want a Jetpack for which the normal state is flying at a stable height, then with some kind of 3D joystick we can move steadily up, down, front, back and sideways. I think all of this is currently achievable but too expensive to implement.

Also, the amount of energy required to lift a person is just to high, so until better ways to store energy are developed, the "backpack" form factor for storing energy will not cut it for practical flights.

Better and safer too. We need to not only store incredible amounts of energy, but do it in such a way that's safe to do so next to your chest :)

Maybe it's silly, but I want wings on my jetpack that are large enough that I can glide, but also that can sheath themselves into each other.

You just want a Gundam suit

Who wouldn't?

Could say the same about the wright brothers in the early 1900s. Longevity of the flight and safe operation can only improve in time. The question is does anyone care. People will be scared of it and if not does it offer anything over cars? It's not like you can fly it over private property , there will be laws that regulate where you can fly it.

Just give me hyperloop tunnels to overlap subways and freeways and I am set. Especially with better bike lanes.

> Could say the same about the wright brothers in the early 1900s.

Yes, you could. But that’s not actually an argument that jet packs will follow a same development path, it’s just survivor bias in action.

They may not, I was just saying we don't know what developments will be made in the future.

Aircraft were improved immensely by new materials since then. But jetpacks are still impractical. Might we see the same level of improvements again in the next century ? (And even if we do, wouldn't "super planes/copters" still be ahead of jetpacks ?)

> the creator cosplaying as whatever service he’s trying to sell it to

That guy is an actual Royal Marine Commando - he's not cosplaying.

I think the point is that when you see demos, it's always him dressed up as a marine, mountain rescuer, etc and not someone else.

What difference does it make who demonstrates it? All that matters is application, performance, and whether it is fit for purpose.

Isn't the point being made that there is nobody else capable of demonstrating it?

The amount of training matters. If it's always him, that has some implications on how hard it is to turn into a product.

And a quick demo doesn't do a good job of showing fit for purpose either. Maybe performance.

I can see this potentially having some usefulness if refined, but from a strictly practical perspective, I can't see many pilots surviving a boarding if the vessel has any firearms. It just lacks maneuverability.

You (obviously) combine it with fire support. Just like a ladder or helicopter assault on a ship, or an infantry attack on land, or really any other military manoeuvre.

Sure, I don't disagree here. My point is that whether it is fit for purpose remains to be seen or whether it's a solution in search of a problem versus alternatives.

I think the earlier posters are pointing out that no one else seems to be able to safely operate the thing, which suggests that it might not be fit for purpose.

I was thinking about this while watching a paraglider with propeller yesterday. I was thinking, maybe you could use tiny jets for this, but the question is why would you... this is already perfect [1]. Seems like jetpacks are a solution looking for a problem and at the same time highly impractical.

1. https://youtu.be/L1Z8YT6w7Rc

In his defence, Richard Browning, of Gravity Industries, was an actual Royal Marine. Granted, reservist, but they still take and pass the commando course. I ran into him a couple of times in the service; while he's not in anymore, "cosplay" seems a harsh term in his case.

While indeed people do not use jetpack in a day-to-day manner, they are becoming slightly more 'available' than you portray.

See this video where one of the corridor crew members participates in a jetpack training.


I think it's more precise to say that they are currently a toy for the rich.

We solved the stability for drones that cost as little as $20. We’ll solve it the same way for jet packs as well.

We solved stability for a rigid drone that’s symmetric and designed for purpose. That’s a lot different than solving for stability for a variable size and weight human that’s wriggling around.

> solving for stability for a variable size and weight human that’s wriggling around.

Was solved for Segways. Just need the third axis and some kind of special emergency landing solution (goo + inflato-ball??).

No, it’s more complex than that. A Segway is counting on the fact that it’s sitting on the ground. The force vector on the rider is purely a function of angle. A jet pack has the issue that there is a moveable center of gravity and moveable sources of thrust that feed back into each other. It’s doable, I’m sure, but it’s also much more complicated than a Segway + another direction.

It’s just a digital gimbal. Similar to a light drone in a breeze.

> Marines demonstrate boarding with jet pack”, and every time it’s just the creator cosplaying as whatever service he’s trying to sell it to this time.

Didn't an actual Royal Marine do this recently, in a training exercise? https://www.popularmechanics.com/military/aviation/a38748085...

This seems like exactly what we'd expect for a technology this new and dangerous, and is certainly a step farther than "the creator is the only one flying it".

EDIT: Per other comments on this thread, apparently the Royal Marine in question _is_ the creator

Just to note, the linked story is about David Mayman of Jetpack Aviation in California, while the other stories you mentioned are (British) Richard Browning of Gravity Industries - the one recognisable by its wrist-mounted supplementary engines. So there are at least a couple of competing inventions.

Sure, there isn't a killer app for jet packs at the moment, or perhaps ever. They were enabled by miniature-scale turbine engines being developed for other purposes. But you never know - some innovation in control systems, or them turning out to be just perfect for some obscure emergency/military task, they might find a niche beyond stunts and tethered tourist experiences.

That's legit R&D.

Marines storming a ship is an obvious use case where the high cost will be accounted for (i.e. we have a lot of expensive gear for specific purpose) and it's a practical scenario. Coast Guard same. And certainly other forces. If we can get the gear to be very easy to use and practical, it could very much enable a kind of acute mobility.

There's little direct use beyond that, however, the development of the technology could yield other things as we learn to make those little jets cheap, efficient and intelligent.

Those systems could absolutely be deoployed onto drones, which opens up a world of use cases.

Exactly, we had "smartphones" before iphone as well and nobody did care.

Blackberries were huge and growing. iPhone definitely expanded the market faster than anyone dreamed. But it was easy to see where the market would go before iPhone.

If it was "easy to see" we wouldn't have iphone dominance.

I just want to point out that global iPhone market share has been hovering between 15% and 20% for years. Android has almost all of the rest. Iphones are not dominant.

Global market share is one kind of dominance, there are others

Easy to see at a high level--phones with web, multimedia support, and app support. Near impossible to guess what exactly what would look like and when.

The pieces where there already, just good enough product with good enough connectivity was missing. In the end iPhone is nothing more than refined PDA...

Devil is in the detail.

A lot of people had smartphones before iPhones. Basically all the 3G phones sold in Europe since 2003. I was working for an operator that got 3 M customers in its first year back then.

Had they a touchscreen as good as iPhone's? Definitely not. Did they had an internet connecting better than iPhone's? Definitely yes because the original iPhone was only 2G.

Anyway, this is only an analogy so let's don't get too much into it.

People don't care about jetpacks because they are crazy dangerous and expensive. This makes them less practical than jumping from a plane with a parachute instead of waiting for it to land.

Quite a few of us cared. The teeming millions may not have, but definitely more than nobody.

Sure, I meant it in context, obviously some people did care, otherwise they simply wouldn't exist at all, what I meant is nobody = niche = not mainstream by any means.

I still think that's an understatement. Not that it matters really, but did you forget about the ubiquity of Blackberry's for nearly a decade prior to the iPhone?

Hmmm... Not sure that Jetpack 2.0 will ever be a thing like the iPhone was.

Helicopters autogyro, planes glide, balloons (usually) lose their lift slowly.

A jetpack, like a rocket, is a thing that has no business flying. Only a large, heavy-handed impulse of energy allow them to oppose gravity. Without altitude and a parachute, there is no Plan B for a jetpack engine failure, loss of fuel, etc.

I think a parachute would be pretty easy to accommodate, at least an emergency one. Maybe it'll still hurt, but cut the pack loose and hopefully you would survive. Not everyone survives helicopter or plane engine failures either.

I certainly don't think jetpacks are a relevant tool for society outside of really niche use cases. If we don't even trust people to fly small drones around the public safely and without FAA regulation and licensing, in what dreamland would we all be able to fly personal jetpacks to the shops, or even recreationally? There are way cheaper, way safer ways to get airbourne as a private aviation enthusiast, so I can see why jetpacks really don't scratch enough itches to have gained popularity.

Parachutes have a minimum altitude, and jetpacks really do not push people into flying high. (What is a problem in more ways than that, because most of the things that can make your flight safer need altitude.)

I had Nokia 7650 in 2004 and I am hopefully not-nobody... these devices, although clumsy, paved the way to the modern mobile ecosystem.

Yes, maybe those jetpacks and micro flying machines will pave the way to future electric-scooter-like flying.

Early adopters absolutely did care.

I'm sure people who fly jetpacks absolutely do care about jetpacks.

I think with a active control unit safe operation should be possible. There are fighter jets that cannot be flewn manually (unstable flight behaviour). Probably range and use case is the problem.

Do we need jetpack 2.0? We (the world) have control software to land a rocket vertically just about OK, but current jetpacks seem to require very complex manual control at the moment.

The question is if they were easy to fly would we need them - the sound and jet blast seem to be a very bad idea when rescuing people from snow and icy mountain rescue conditions and all the military demonstrations I've seen just seem to suggests it's a loud, slow moving target.

The only impractical thing is the cost. I tried to look it up and found a quote saying if you have to ask you can’t afford it. If every house had one our kids would be flying them in a week. If I could afford one I would also be spending my days flying them. The only issue is cost. I have to ask the price so obviously can’t afford it. But believe me if I could I would not stop until I mastered it.

No revolutionary technology can be expected to be practical for casual users. They are building a cool product and I hope they find a market even if a niche once.

But I'd prefer https://www.youtube.com/c/Jetsonaero/videos to a jet pack too :)

a widely usable 'jetpack' would actually be more like a ducted-fan coaxial octocopter that you wear, with flight stabilization/onboard flight controller not very dissimilar from a large commerical cinema filming octocopter.

if it relies on the person's skill to fly it and has a 5-10 minute max flight time, of course it'll be a niche thing...

Theoretically, if you could add adjustable mechanical joints, you could hook up a flight controller to it and fly it. Could you add the necessary joints and motivators and stay inside a reasonable weight? Not so sure.

with arducopter and common COTS flight controllers people have made monocopters that use servo motor controlled vanes:


That would require the three points to be rigid other than the vanes. But vectored thrust is a thing for jets too, so it's definitely possible.

Furthermore if you want the sensation of a jet pack, there’s the jet lev, which seems much safer. The article mentions that this should only be flown over water on a tether, so what’s the benefit over a jetlev?


That's like the Flyboard, another water-jet system.[1] That's the world champion flying.

The Flyboard people now have the Flyboard Air.[2] This is a real flying hoverboard, powered by what is believed to be a group of model aircraft jet engines. It's not easy to fly. They require 50-100 hours in the water-powered version before attempting the jet-powered version.

It's very cool, but it's for people who find skateboarding stunts too easy.

[1] https://www.youtube.com/watch?v=0JhUSu8v2N4

[2] https://atlanticflyboard.com/flyboard-air

> “Marines demonstrate boarding with jet pack”

https://www.youtube.com/watch?v=suHOLFhbwsM is the video for anyone interested

Question: How impracticable is the following:


you have a machine with micro-thrusters (of whatever fuel-source)

It is driven by modern drone tech for stability.

How driven, super simplistic maths for establishing thrust.telemetry.balance...

How the FUCK has this not been solved?

A belt of jets. They fly you without killing or burning you.

We are significantly evolved for this to happen...

Seriously. This is a solvable thing. Do it.

it does feel like we made lots of progress though. as we need less fuel for them, they get easier to use, and safety improves we should start seeing some real use cases

Nobody cares because we have something better. It’s called paramotoring.

Saying it changed my life wouldn’t be an overstatement. The ability to store it inside my sedan, travel anywhere, take off with my own feet, fly anywhere for around 4 hours, and land basically anywhere… is just magical.

It's a pet peeve of mine that people think that sci-fi authors writing decades before the tech exists somehow got the design right, just because Hollywood made some pretty moving pictures that fired up your imagination.

It's hard enough to design things in the real world when you've got the tech in hand. There's no way to think that people got it right decades earlier with even larger disadvantages.

The reality is we don't have jetpacks because jetpacks suuuuuuuuuck. Paramotoring turns out to make a lot more sense. It may not be the picture in your head, but it can be real.

Also, we don't have flying cars because flying cars suuuuuuuuuck. We don't have heavy-duty voice interfaced computers because they suuuuuuuuuck. We even have the tech now for those, and they suuuuuuuuuck as the only interface. (They can work if you're dedicated and have no alternatives, as people program with pure voice interfaces, but they only use them because they're the best alternative they have.) Computer interfaces don't look like LCARS Star Trek interfaces because those interfaces suuuuuuuuuck. And so on.

The other side is my own pet peeve: thinking that sci-fi authors were visionaries for putting something out there before anyone else makes it real. One reason we don't have flying cars could be battery tech, taking your example. There's a ton of cool shit happening in aviation as batteries improve.

Flying without lift from wings or like as people think of sci-fi flying cars isn't practical, unless we break the physics as we understand today. I honestly can't think of anything more wasteful than hovering flying car...

Even if you fix all the other problems with flying cars, you're not gonna fix the noise issue. They are simply too loud to use in populated areas.

> you're not gonna fix the noise issue

Firstly, I wouldn't be so sure about what future tech might bring. Perhaps if "flying cars" get closer to something consumers could use in a neighborhood, it will be profitable to look into and maybe something can be done about it.

Secondly, for many of the young men living near me, noise is more of a perk than an issue. You could probably sell them on the idea that the whole town gets to hear that they're rich enough to afford a flying car.

"How many angry hornets does it sound like?"

"All of them."

I love flying car demo videos with dubbed-in music rather than live audio....

Was listening to a comedy podcast and they mentioned the famous Minority Report hand waving interface and the host responded with “Wait we have that now, but you do it on a desk instead of above your head. Isn’t that a lot better?”

Android is starting to look quite LCARS https://twitter.com/benjiweber/status/1457039757112922115

Jetpacks only suck due to the lack of a compact power source, one of the things that's commonly handwaved in scifi. If we had a magical power source they'd provide a more dynamic flying experience than gliding.

They have a poor backup if a component fails, they're either going to be blasting something hot or something very fast out some set of ports which raises a lot of practical issues, they're always going to be very loud, greasing them up with enough AI to be safe for a normal person is going to be a massive problem, they'll always be difficult to control because such a small, fast thing is going to be super responsive and thus very twitchy and difficult to fly (or, to put it another way, "more dynamic flying experience" is a con, not a pro), and the list goes on.

Basically, a jet pack what you get if you take a minimal safe flying vehicle based on jet propulsion, then you strip away a huge number of components. The result is intrinsically unsafe.

Paramotoring isn't the safest thing either, but at least it's humanly feasible.

In fairness, if you let the word compact do a lot of heavy lifting, I don't see why a sufficiently compact power source would have to be dangerous to fly. Give it enough redundant cells and enough AI to keep you upright, sure why not? From an abstract physics perspective, flying is only a little more complex than keeping a Segway upright. Look at what modern ejection seats can do.

The problem is that we are orders of magnitude off in terms of power density, and it seems unlikely that we'll bridge that without some sort of major revolution in physics. So sci-fi it remains.

> It's a pet peeve of mine that people think that sci-fi authors writing decades before the tech exists somehow got the design right, just because Hollywood made some pretty moving pictures that fired up your imagination.

Many people who believe in science actually believe in science fiction.

most of the things you mention suck not because they're bad in themselves, but because they require infrastructure in place before they can be effective, let alone better.

and we don't have infrastructure in place, because we have other solutions that work already, and the cost to change them would be too big and even if we wanted to we'd have to find a way to slowly phase them in over many decades.

you're basically that guy from 20 years ago who yelled "fossil fuel is good because solar panels suuuuuuuuuuck " :p

We have flying cars, they just don't look like what sci fi authors imagined, and we call them helicopters

https://www.youtube.com/watch?v=L1Z8YT6w7Rc - guy flies to 17,500 feet on his paramotor.

I didn't know they were a thing before watching this. Amazing.

Well, paramotors are actually a bit less prone to mid-air collisions (aside from showing off, wing tip bumping etc.), because they're usually brightly colored, the pilots have perfect visibility, they fly slow and usually pretty low (lower than most airplanes).

I think it's more due to the big sky theory.

When flying even a modest GA aircraft VFR, there isn't much time to react if you've been looking down at foreflight/instruments for 30 seconds while heading straight towards a paramotor which has no ADS-B out. This says even more for IFR craft that move much faster.

Would it be feasible to do ADS-B on a paramotor?

Technically? Yeah, someone could probably make a small device that incorporates all the necessary gadgets (would need to read the FARs) and then broadcast a signal.

Honestly, even if someone just scraped together GPS and a transmitter with a color changing LED (eg: red=fault, green=transmitting) and then worked with the FAA to set aside a squawk code for these devices, they would improve safety for everyone in the sky while also creating a product that would likely become a standard for several decades, if not more.

Dude takes off from a rather unsettling neighborhood, damn.

Looks like a lower middle class neighborhood that was newly built. The pumpjack in the middle of it is a nice touch.

TIL about paramotoring. I'd seen the rigs before but didn't know the name.

I googled it and the first thing that came up was a YouTube video about the 5 most dangerous things about paramotoring. :)

I wouldn't try paramotoring without doing at least a 6 month paragliding course first. Which in fact I did when I was 21. After I saw a colleague make a judgement error, fall from 30ft, hit the ground and jump like a soft ball I became stressed during flight. He had flown a DHV3¹ paraglider though and was not experienced enough to fly that wing. Current DHV1 wings are much more safer and very performant compared to 2000 era wings that we've flown. Shortly after the fall incident a guy I became acquainted with died during a competition. I just gave up because it stopped being fun. My instructor had an accident with a powered hang glider few years afterwards. He still has a bad limp to this day. He has always been very safety conscious and had at least 25 years of prior aviation experience, parachuting and paragliding, when his accident occured.

Anyway, I find paramotors quite offensive because they make an awful lot of noise and smoke and the pilot's position is quite unnatural compared to normal paragliding because the motor pushes him or her forward. Maybe when we'll have electric paramotors under 10 kilos things will change for the better.

1. https://www.dhv.de/en/testing/dhv-classification-of-paraglid...

The transitive PTSD from your fellow pilots dying is real. I quit after 800+ flights (including motored, and yes it is incredible) after the 5th death of someone I'd either been close to or at least on adventures with. Not to mention all the broken vertebrae which is a lot more common than death. In the span of a few years I saw three ridiculously experienced instructors (one had like 8,000 flights) smash into the ground, then spend 2 months in the hospital and a year recovering.

The fact that we know what mistakes they made is a red herring. You'd have to be a fool to think you're going to be the first paragliding pilot in history to never make a potentially fatal mistake. One of them, a friend and a very good pilot, simply pulled his brake half an inch too far. It was a perfectly calm evening.

There were two warring factions at my local mountain. One organized around the idea that paragliding can be made safe. My camp maintained that 'safe' and 'paragliding' should never be in the same sentence without an 'isn't' between them. Hikers always opened conversation with "Is it safe?" The other camp would say "Oh yes, quite, and would you like a ride for $200?" Our camp would try not to laugh. I'd usually reply with, "Does it look safe?" We said it was all about risks and percentages, with the understanding that the risk of dying or being crippled with a slow glider in perfect conditions is always > 0.

I'm not saying it isn't worth it. It's totally worth it, though it's easier for me to say since I got out unharmed. Rather, I developed a discomfort that prevented me from enjoying it. Not fear - but a kind of disillusionment. Because even though my instructor said "It's not safe." over and over, and even though I repeated it to others, secretly I believed it was and it took 8 years for observed events to wear that belief down. A big part of me hopes I return, maybe after my parents are gone or I'm their age or something. There is really nothing like it in the world and I doubt anything I ever do will ever energize my soul the way free flying did.

On the flip side, your chances of dying if you don't go paragliding are about 99%, which is awfully close to your chances of dying if you do go paragliding. It's terrible and traumatic when your friends die (or your children, Jesus), and enormous caution is worthwhile, but not in order to survive. You're guaranteed not to survive.

Is paramotoring safer (i.e., longer life expectancy) than paragliding?

> Is paramotoring safer (i.e., longer life expectancy) than paragliding?

The stats are skewed in favour of paramotoring, althout the added complexity means more margin for error. The safety plus to paramotoring is that you can fly on a day without any wind, while paragliding requires at least a 2 m/s wind to descend from the top of a hill or moutain and about 5 m/s to soar next to a slope, dune or ridge. Paramotorists also rarely engage in aerobatics which is probably why the stats are skewed. They also almost never need to perform special altitude loss procedures like big ears, tip stall, B-line stall or spiral dive.

This is untrue, paragliding doesn’t require any wind for descending. You generate your own airspeed. There are also other ways of staying up than soaring (thermals). Additionally, wind isn’t the source of the risk, rather wind variability and turbulence. Flying in low wind doesn’t add to the risk profile.

Yes, you could take off in zero wind and fly off a cliff but it's quite boring. I wouldn't even bother hauling my paraglider up a cliff on a windless evening when the there are minimal thermals. Not without a lift. The risk profile is is quite debatable. But the general consensus is that paramotoring is safer. I see it simply carying other risks, like tangling your lines in the propeller, improperly operating the engine etc. Also the number of yearly fatalities is smaller, which doesn't actually say anything without total hours of flight. For paragliding I think most uncontrollable risk mainly revolves around weather.

Hmm, so maybe one reason paramotoring is safer is that the safest time to go paragliding or paramotoring is when there's no wind and thus no wind shear (etc.), but that's inconvenient and boring for paragliding?

Estimating total hours of flight in the US seems like it would be difficult since there's no licensing regime.

Yes, pretty much. Once can paramotor on a flat field with no features on a clear windless day. Plus there's no need for altitude loss procedures which carry some risk, no aerobatics, the wing is almost always properly loaded because you carry a 30 kg motor on your back and you don't need all the wing area that you normally need for paragliding, so the risk for wing collapse is smaller. There are simply other risks involved.

I would disagree on boring, thermal flying on a windless day is amazing, proximity flying, a chill sled ride. Many fun ways to play without wind.

I wouldn’t comment on safety comparisons with paramotoring without more statistics.

Thermal flying implies wind or updraft.

I haven't found any proper statistics, just fatalities without hours of flight for each activity. Which are really just anecdotes masked as statistics.

Sure, but you’re twisting words. Wind is pretty much always used to refer to horizontal air movement.

Thank you!

Have you considered sailplanes? Requires quite a bit more organization than paragliding, which I guess is the main drawback. But you do have a rigid frame around you that will absorb a lot of energy if you end up making enough bad judgements for it to be a problem.

Flying is nice but shaky and unpredictable weather still makes me uneasy. If I'll ever try it again it will be in a sailplane or a light airplane.

The best comment I've read today. Thank you for sharing your experience.

I found the same video it looks like all those dangers are preventable? Don't do acrobatics at low altitude, don't fly over water, don't start the engine on the ground, don't buzz trees or other obstacles, don't get close to other paramotors in flight.

I've just been getting into paragliding (i.e. without the motor), and have been absolutely loving it. It blew my mind to learn that by riding thermals, paragliders can essentially stay in the air indefinitely. My longest flight so far has only been about 15 minutes, but people are regularly in the air for hours.

For some more inspiration, check out "speed flying" — essentially, paragliding with skies: https://youtu.be/UwWLnaME0CI

I used to do paragliding back in college, definitely prefer it to paramotoring because no engine noise and much more agile wings.

However I wouldn't relate it with "speed flying" because speed flying is a truly an extreme sport with extremely high mortality but paragliding is a chill flying unless you choose to make it extreme.

Paragliding is so safe these days, the wings are very stable and spontaneously return to airworthy shape if disrupted. Flying is very chill, to do something at high speed you usually need to build up energy by spiralling or swinging the wing.

Speed flying on the other hand uses much smaller wings and that makes them very dynamic. They fly at much higher speeds and they have high kinetic energy all the time which results in very large movements even at small inputs from the pilot.

Utah has a couple spots that are popular for paragliding. I'll never forget the time we visited one of the popular launch spots and saw a man get so high within minutes that we couldn't see him anymore.

Living in the Alps I have seen so many of these. I always prefer to stick to riding on the snow, rather then flying.

You've got my attention.

Been watching these kids with paramotors on YouTube blaze across fields, drop in on a rural McDonalds.... It looks like fun ... and safe enough?

It's the best thing you can do with your clothes on, lol. And extremely safe. I've been flying for 4+ years and I never even twisted an ankle.

Actually, if you like adrenalin, I'd suggest looking elsewhere. I did skydiving for many years before discovering paramotoring, and they are completely unrelated activities.

Yes, you can do high speed flying and "slalom" with your paramotor, but 98% of us don't. It's a contemplation sport. Like going on a bike ride or jetski ride with your friends, but in 3 dimensions. It's all about the views, soaking up the scenery, and having a good time in the sunset or in the sunrise. If you live near the beach, you can fly all day; if you live in the countryside, you'll probably fly early in the mornings or in the sunset, due to the lower thermal activity (it gets bumpy otherwise).

If your engine fails ... you have a huge "parachute" that sails 6 meters forward for ever meter down. Actually, every single landing we do, we are either with our engine completely shutdown or idling. I've had 3 malfuctions in these 4 years; as long as you're flying watching your "safety cone", you'll slowly glide to a pleasant landing.

If your main glider fails (they don't, but our main enemies are kites; their lines can cut through our lines like butter), you still have a reserve chute that you can throw as a last resort.

If you fly over water, equip yourself with flotation devices. There are many specific to paramotors that inflate automatically.

What defines the sport is the wing you choose. You'll get trained by an instructor, and he'll guide you to the best wing according to your weight and desires in the sport.


- Get professional training; - Get a good equipment and a wing suited to your weight; - Don't fly over water without flotation; - Always watch your "safety cone" in the event of an engine out; - Don't fly spirals near the ground (don't be a showoff); - Beware of your weather forecast and land if winds go over your comfort speed;

You literally become a drone (mine is getting dust and never flies anymore). It's incredible. If you have the chance, get yourself trained, you'll add a whole other dimension to your life.

> and safe enough?

They're like motorcycles. Do everything right and it's almost safe (someone else can hit you on the road and there are rare meteorological phenomena able to bring a paramotor down, e.g. a microburst), but even small errors can result in severe injury or death.

Nothing is safe, you just have to acknowledge the risk involved and accept it.

Risk is everywhere, if you accept the risk involved you may find yourself having a good time.

Back in 1884 at Coney Island people paid a nickel and lined up for a 600-foot ride (at 6 miles per hour!) on the first 'roller coaster'. (Some of them probably fainted!)

> Nobody cares because we have something better. It’s called paramotoring.

It is still very bad if you want to use it for something useful and not just entertainment... It is very susceptible to malfunction when it is a bit windy...

It's such beautifully "simple" system that makes so much sense. I love it.

lol @ bajillion dollar R&D jetpack with ai controlled thrust vectoring

wow! I have seen this in real life but had no idea what's the name.

It definitely seems simpler and safer than jetpack.

What is a good entry level kit? I know nothing and this sounds amazing.

I'm giving you some pointers below but the best thing is to get proper training from an instructor. Helping you choose the right equipment for you is a big part of it.

Your equipment has 3 main components: your engine (check out Vitorazzi, their "Moster 185" is definitely the most popular engine in the world), your cage (check out Parajet https://parajet.com/ - they have some cages already assembled with the Moster 185) and your wing (I fly Ozone - https://www.flyozone.com/paramotor/).

How/where did you get training?

You can find a club in most large cities. In the US at least, the biggest problem is getting far enough away from the city so you don't become a hazard to commercial plane traffic.

I live in the DFW metroplex, and you have to drive almost 100 miles out of the city to take-off and then you're pretty limited on where you can fly due to the abundance of small airports nearby.

There are maps available that show what kind of airspace is around you. I forget the specifics as it's a been a few years since I looked into it, but there are different designations for what/who is allowed to fly where and paramotors are very low on the totem pole in terms of priority and access allotments.

Just google for paramotor training, there are many schools in the US. I suggest get training near the place you plan to do most of your flying, because flying at the beach with constant, laminar, mid-strong winds is very different than flying at the countryside with bumpy and low-mid winds.

If in doubt, learn to fly near the beach. The views are amazing :)

no much better when you can't use it when it is windy....

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