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Flying cars (spmx.ca)
49 points by qqn on Aug 6, 2019 | hide | past | favorite | 51 comments

Most people are lucky to drive a year without a costly mistake. Put them in the air, and their mistake (or a self-driving mistake) means death.

And even if we can make personal air travel safe, how ever are we going to coordinate it?

I appreciate the advances we gain from the crazy/idealistic people who invest time or money on flying car ideas, but it is just never going to happen. The earth will burn and humans will die before that becomes a thing.

Some HN readers are working for auto driving companies, and they know how hard it is to be safe on the ground. Now add the whole of vertical space, plus aerodynamics, to the equation. These people might as well put their energy into teleportation (not really a pun intended, but it's kind of there).


On the other hand, software that manages traffic in the air automatically might be much more simple. No kids suddenly crossing the street, no traffic deviations due to construction, no obsolete system of signalling that can be manually overriden by any construction worker, etc.

No unpredictible flying things like birds, no invisible wind gusts, no air currents, clear trajectories, etc

Birds already do most of the work to avoid collisions, and automated control of low-flying "cars" can work if there's a good system of coordination (ADS-B++) and "lanes". Yes, we can have lanes, which I imagine will exist in layers above freeways. Of course there will be times where weather shuts down the air traffic, but with computer control of the aircraft's navigation they could be usefully integrated into the national highways and airspaces.

Indeed, this is why UAVs preceded unmanned cars. See the DARPA Grand Challenge.

Disagree. Autopilots for aircraft have been proven technology for 100 years. It's a dramatically easier problem because there are many fewer edge cases, more degrees of freedom for the control system to exploit, no fixed roads to follow, and less traffic. And with widespread use of transponders, aircraft talking to each other is already common. It's still considered future technology for cars.

A plane autopilot isnt really the same as full self driving though.

You might be right but in the flying car future we'll have millions of flying cars doing the daily commute, all trying to land in the middle of a city. So I guess flying cars will be like normal cars, the easy bit is the middle bit, either flying in well defined lanes, or driving on the motorway. The hard bit is at either end.

> So I guess flying cars will be like normal cars, the easy bit is the middle bit, either flying in well defined lanes, or driving on the motorway.

Not that easy considering that at least two Tesla's were totaled driving themselves on a motorway...

One by straight up running into a splitting lane and another just ignoring a truck and driving into it.

Stopping an aeroplane stalling is supposed to be easy too. I guess easy is relative whether for cars or planes.

Take off, landing and cruising are easy to automate. IMHO, the single purpose of a pilot is to handle failures. The experience (for example https://en.wikipedia.org/wiki/Air_France_Flight_447) shows that it is difficult to react correctly when inputs are unreliable and that many crash are avoided thanks to smart (and creative) pilots (see Hudson landing).

> Take off, landing and cruising are easy to automate.

Agree with take off and cruising, but landing is magnitudes more complex, at least much more difficult for humans. Do you have a source that this is reliably automated?

> many crash are avoided thanks to smart (and creative) pilots (see Hudson landing).

Actually, the emergency plan in case of engine failure after take off always gets discussed on ground before each start, along with defining an emergency landing area. So I would assume the Hudson river often gets scoped in those preflight discussions, even though such incidents rarely ever happen.

Source: I took flight lessons a long time ago.

>Agree with take off and cruising, but landing is magnitudes more complex, at least much more difficult for humans. Do you have a source that this is reliably automated?

I believe all modern airliners are capable of fully automated landings as long as the airport supports them. To the point where automated systems can land in zero visibility where pilots are incapable of doing a manual landing:



These systems are so precise I've read they had to add a random factor to the landing location as the planes were all touching down on the exact same spot and damaging the runway.

This has been the case for a long time now. The landings are all still initiated by the pilots but there doesn't seem to be any fundamental technical reason fully automated flights couldn't be done today. But since we still require pilots to handle failures it's best to keep them in the loop instead of dumping a broken state with a huge workload when the automation happens to fail.

> Agree with take off and cruising, but landing is magnitudes more complex, at least much more difficult for humans. Do you have a source that this is reliably automated?

Landing has been automated since the 1960s. The first airplane to do it in service was the De Havilland Trident[1]

[1] https://www.youtube.com/watch?v=flVcxfOnWi0

Undoubtedly you're right: getting flying cars to work is an unfathomably difficult task.

But does that mean it truly will "never" happen? I imagine saying we'll never see flying cars reach mainstream is akin to those who once thought attaching a motor to a horse carriage would never work (though, to your point, the triumph of the motorized vehicle has brought disastrous outcomes along with its benefits)[1]. It's hard to see the future when all we've got is the past and present to evaluate it by.

And yet, we've had private aircraft for hundreds of years and that's gone reasonably well. Scaling that private fleet up and including car-like vehicles doesn't seem too far off, though the challenges are numerous and daunting. Flying cars will likely not include the same amount of training and preparation as private planes. The gamble seems to be software can help take on much of the burden, only time will tell if that's going to pan out.

1. What about those who could never fathom a globally connected network of information? Or the precedence of touch-based interfaces? Or the reliable, safe electric car?

I don't agree with your sentiment. There are many possible ways to make this work in a useful way. Let me try with just the first example that comes to mind. I live in the Bay area and I'll use it as the environment.

Imagine a dozen or so "carports" for these flying cars, conveniently located close to where people need to commute to/from. Trace routes between these, and setup scheduled travels between them with a high enough frequency. Now all of a sudden you can commute from Marin county to downtown SF, or from SF to Oakland, in just a few minutes, while at the same time removing cars from the existing road infrastructure.

Yes, there's the problem of noise. Cities are already very noisy, what if you limit these flying cars to a time window where it doesn't annoy people too much, e.g. 8am to 7pm.

Still on noise: what if you devise a way to limit the noise when close to the actual carport, e.g. with sound barriers that mitigate the noise for the first 50-60 feet of take-off or landing.

What if the first 300 feet of take-off and landing are assisted with a different vehicle, built on purpose to make less noise than a flying car?

Or, what if noise is too bad, and you limit this to placing carports in areas where you won't disturb neighbors too much, and where the path between two carports is over the ocean, e.g. Santa Cruz to San Francisco, or Miur Beach to Ocean Beach.

On the driver: I wouldn't want a human being to be in control. These routes should be taken by completely automated vehicles. It's easier to accomplish than a level-5 autonomous car, because you don't have obstacles - especially if these route corridors become a no-fly zone for other things like drones, etc.

Here you are, it's a poorly designed plan, but it's a start.

And I'm sure that by iterating more and more the plan can become acceptable, then viable, then a good idea.

Re: Most people are lucky to drive a year without a costly mistake. Put them in the air, and their mistake (or a self-driving mistake) means death.

I would expect bots to control masses of flying cars in populated areas, not human drivers. The air is actually simpler to navigate because there's not much around besides other flying vehicles. You don't have pedestrians, potholes, fallen trees, fading lane paint, etc. (Maybe flying sharks during a sharknado, but those are relatively rare.)

>Most people are lucky to drive a year without a costly mistake

I think most people manage to go at least a few years between anything more than door dings.

Isn't it going to be easier to be safe on the sky as there's much more space, i.e. collision rate will be much much lower?

    > collision rate will be much much lower?
I agree that colliding with other flying cars is going to be rare.

The issue is that when there's a failure of any kind, you can't just "pull-over" in a flying car. You need to land.

Flying cars just aren't going to be a big market, IMHO, in the foreseeable future. Pilots need to be qualified, and even then, they need to be in a place that can truly accommodate flying vehicles-- the middle of nowhere. And if you're going to that, you might as well buy an actual plane rather than an all-in-one hot mess of a flying car.

>The issue is that when there's a failure of any kind, you can't just "pull-over" in a flying car. You need to land.

Honestly, this (and noise/general nuisance factor) would seem to be the bigger issue than reliable autopilots, which presumably can be gotten to over time.

If you scale up personal flying vehicles to mainstream use, even with a mandatory costly and rigorous maintenance schedule, it's hard not to believe that you'd have lots of these dropping out of the sky and causing fatalities and damage on a daily basis.

There's a lot of open space available, but transportation doesn't evenly distribute itself among the available space. There will be clustering points because people want to go the same places or use the same thoroughfares, and those areas will have higher risks of collisions.

Before the 60s, collisions were rare per mile traveled, but a roughly yearly occurrence across major commercial airlines. It took a lot of policy and engineering work to reduce their frequency: https://en.wikipedia.org/wiki/Mid-air_collision

Automated systems might be able to fix this? They wouldn't have to deal with the paper bag problem, just avoiding every obstacle, so that's a plus. But sudden braking isn't the near universal solution or mitigation that it is with driving, and predicting the movement of other airborne objects is really hard, so those are minuses.

Beyond collision prevention, there's an interesting general question in this thread about whether automated flying or automated driving is a more difficult engineering problem.

I can see arguments for both sides, would love to hear a really thorough analysis, preferably by someone who has worked on either or both problems.

Small planes flown by amateurs are extremely unsafe compared to most kinds of transportation.

It's highly correlated with pilot experience, and it's not monotonic. Pilots with 20 hours are pretty safe because they are scared of everything. Pilots with 2000 hours are extremely safe because of their experience. Pilots with 200 hours are quite dangerous because they're complacent and overconfident.


It's about the same if not less dangerous than riding a motorcycle.


Riding a motorcycle is extremely unsafe.

True flying cars exist. I watched one go from car mode to plane mode, fly around, land, and drive off the runway in car mode again at EAA in 2013. They work and they meet all the expectations we had when we were kids. Except one: They cost over a quarter million dollars. Everybody said we'd have flying cars, but nobody told us only rich people would be able to afford them.

This is why I hate when people say "we were promised flying cars, we got 140 characters". We totally have flying cars! We just don't use them because learning to fly safely is way too expensive and impractical for most people. (The relevant corollary being, if it wasn't, more producers would enter the market and flying cars would become affordable.)

> nobody told us only rich people would be able to afford them

This is not correct: William Gibson has warned about that as early as 1993: "The future is already here — it's just not very evenly distributed." [0]

[0] https://en.wikiquote.org/wiki/William_Gibson#Quotes

These might just be early adopters in the longtail of personal flight technology.

If personal flight starts as a luxury good to pay for research and development, as those innovations become widely known the price should come down to make it accessible to everyone.

Here's the one I saw fly in 2013. Apparently I was watching the flight in this video from the ground.


>nobody told us only rich people would be able to afford them

Rich people will also have professional pilots anyway.

Even so, rich people don't seem to be "driving" them. They can afford overpriced Rolls Royces or Bentleys but don't see them buying flying cars. Wondering why, given that the technology has been around for a while.

I'm pretty sure there are no quarter million dollar flying cars which are not obvious death traps.

The original flying car was the light helicopter, particularly the designs by Robinson Helicopter in the 1970s. The idea was that upper middle class professionals (doctors, lawyers, maybe computer programmers, etc) would prefer to learn the helicopter and commute into the city from the countryside than drive to work. This idea didn't pan out, because many/most professionals prefer city life (once the race riots stopped in the 70s), and flying light helicopters is both difficult/stressful, extremely expensive ($200/hr) and fairly dangerous (motorcycle tier or worse). Those who do it, do it as a hobby. https://philip.greenspun.com/flying/helicopters

>Wondering why, given that the technology has been around for a while.

Probably because they got rich by being able to recognize a bad idea.

Also, being rich, they probably want to live longer, not die in a half-baked, worst-of-both-worlds technology.

"We have flying cars today, they're called helicopters" - Neil deGrasse Tyson

"We have self-driving vehicles today, the are called buses and trains" - lots of people

"We have level-5 autonomous vehicles today. They're called horses." - me.

I do think there's a point here to be made. I'd imagine the helicopter and personal flight space to look a lot different if regulation about flight would never be introduced, for one reason or another.

I remember the Moller Sky Car ads that were in every Popular Science magazine of my youth 35-40 years ago. That beautiful, deep red, futuristic machine with the rotating engine pods was something little me was sure I'd be flying around in some day. Life disappoints.

I know how you feel. I used to live in the same town as them, and dropped by their location once to check it out. But still no SkyCar in my garage. Surprisingly, it appears they still exist.


Yeah I read some article years ago saying they were embroiled in lawsuits. I am surprised they are still claiming the M400 is "in development" after this long. Sadly seems more of a long term money siphon than any real project.

Thanks for the commentary guys, it’s been fascinating churning over all this even more. Thoughts:

- Safety is the same issue as always, only it’s being ironed out faster than before. Controlled vertical landings, 3D space, and redundancy help a lot. I don’t foresee many flying high enough to get really hurt. Maybe things like undercarriage cushions or redirected waterways underneath major traffic flows could help even more.

- Noise cancellation tech is already out there, as well as near-silent aircraft without moving parts: https://youtube.com/watch?v=boB6qu5dcCw

- Main arteries will be less condensed, but much more, much smaller traffic will appear and that’s going to be a new problem. The death knell for intracity public transport?

- Well-made points about “actual” flying cars not actually being used. Maybe it would have been the same for cars if someone made motorized horses instead of the automobile?

Thank you for all the resources. I really liked the random touchdown point, underlining how exact our tech already is. I've polished the post quite a bit, adding a lot of these extra things to it. If anyone can clarify the paper bag problem @brownbat mentioned and what @blunte meant by "s/trans/tele" I'd really appreciate it.

In our small town Nitra/Slovakia/EU, there is one very motivated and intelligent inventor, who created a Car (that can actually drive on public roads)... Also the car can transform into plane... and fly 700km.


Actually now, He struggler's after investors took all the IP and removed the him self from the company. Very interesting story! Part of there sorry is "He" crash-landed the plane and survived! That's something you can't test on real person :) in fact very interesting story about a person who dedicated his life to a vision of flying car.



Do you want your neighbors to own flying car?

Good point, theres a small airfield near us and the occasional plane does a circuit overhead, which is different. 1000s every hour? Not so much.

My neighbors? Oh yes.

For people who are into this, also check out the goflyprize.com

It was pretty fun to see what designs people came up with. I think some of these companies even had YouTube videos with prototypes already working.

I wonder what a typical sky would look like in any semi populated area if flying cars take over. Seems like open blue sky would become another luxury of rural living.

(...) the American imagination has frozen up solid around the unworkable fantasy of the flying car.

Listen to most discussions of flying cars on the privileged end of the geekoisie and you can count on hearing a very familiar sort of rhetoric endlessly rehashed. Flying cars first appeared in science fiction—everyone agrees with that—and now that we have really advanced technology, we ought to be able to make flying cars. QED!

The thing that’s left out of most of these bursts of gizmocentric cheerleading is that we’ve had flying cars for more than a century now, we know exactly how well they work, and—ahem—that’s the reason nobody drives flying cars.

Let’s glance back at a little history, always the best response to this kind of futuristic cluelessness. The first actual flying car anyone seems to have built was the Curtiss Autoplane, which was designed and built by aviation pioneer Glen Curtiss and debuted at the Pan-American Aeronautical Exposition in 1917. It was cutting-edge technology for the time, with plastic windows and a cabin heater. It never went into production, since the resources it would have used got commandeered when the US entered the First World War a few months later, and by the time the war was over Curtiss apparently had second thoughts about his invention and put his considerable talents to other uses.

There were plenty of other inventors ready to step into the gap, though, and a steady stream of flying cars took to the roads and the skies in the years thereafter. The following are just a few of the examples. The Waterman Arrowbile on the left, invented by the delightfully named Waldo Waterman, took wing in 1937; it was a converted Studebaker car—a powerhouse back in the days when a 100-hp engine was a big deal. Five of them were built.

During the postwar technology boom in the US, Consolidated Vultee, one of the big aerospace firms of that time, built and tested the ConVairCar model 118 on the right in 1947, with an eye to the upper end of the consumer market; the inventor was Theodore Hall. There was only one experimental model built, and it flew precisely once.

The Aero-Car on the left had its first test flights in 1966. Designed by inventor Moulton Taylor, it was the most successful of the flying cars, and is apparently the only one of the older models that still exists in flyable condition. It was designed so that the wings and tail could be detached by one not particularly muscular person, and turned into a trailer that could be hauled behind the body for on-road use. Six were built.

Most recently, the Terrafugia on the right managed a test flight all of eight minutes long in 2009; the firm is still trying to make their creation meet FAA regulations, but the latest press releases insist stoutly that deliveries will begin in two years. If you’re interested, you can order one now for a mere US$196,000.00, cash up front, for delivery at some as yet undetermined point in the future.

When people insist that we’ll have flying cars sometime very soon, in other words, they’re more than a century behind the times. We’ve had flying cars since 1917. The reason that everybody isn’t zooming around on flying cars today isn’t that they don’t exist. The reason that everybody isn’t zooming around on flying cars today is that flying cars are a really dumb idea, for the same reason that it’s a really dumb idea to try to run a marathon and have hot sex at the same time.

Any automotive engineer can tell you that there are certain things that make for good car design. Any aeronautical engineer can tell you that there are certain things that make for good aircraft design. It so happens that by and large, as a result of those pesky little annoyances called the laws of physics, the things that make a good car make a bad plane, and vice versa. To cite only one of many examples, a car engine needs torque to handle hills and provide traction at slow speeds, an airplane engine needs high speed to maximize propeller efficiency, and torque and speed are opposites: you can design your engine to have a lot of one and a little of the other or vice versa, or you can end up in the middle with inadequate torque for your wheels and inadequate speed for your propeller. There are dozens of such tradeoffs, and a flying car inevitably ends up stuck in the unsatisfactory middle.

Thus what you get with a flying car is a lousy car that’s also a lousy airplane, for a price so high that you could use the same money to buy a good car, a good airplane, and a really nice sailboat or two into the bargain. That’s why we don’t have flying cars. It’s not that nobody’s built one; it’s that people have been building them for more than a century and learning, or rather not learning, the obvious lesson taught by them. What’s more, as the meme above hints, the problems with flying cars won’t be fixed by one more round of technological advancement, or a hundred more rounds, because those problems are hardwired into the physical realities with which flying cars have to contend. One of the great unlearned lessons of our time is that a bad idea doesn’t become a good idea just because someone comes up with some new bit of technology to enable it.


Wow, I thought that writing sounded familiar; fancy encountering you here, Mr Greer! Huge fan.

Most people cant handle driving on the road, let alone in the sky. Especially if there are more people in the air. Wait until the cars start falling out of the sky killing people.

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