Are Flying Cars Even Possible?

[Vinyadan]

Oh yes. "Well, I guess I'll just crash my car into an atomic plant".

Or crashing against a Black Hawk helicopter that was patrolling the area because of some big assembly thirty km away.

Or, even better, flying over residential areas.

[Jay R]

Have you ever been on the side of the road with a car that wouldn't work? With a flying car, you'd have fallen to earth -- in a vehicle filled with explosive liquid.

[Vinyadan]

Have you ever been on the side of the road with a car that wouldn't work? With a flying car, you'd have fallen to earth -- in a vehicle filled with explosive liquid.

My worries are mostly for the people and houses below. Car accidents are already ugly, a still car falling from 500m into your roof would hit with 6 million joules: that's like being hit 30 thousand times while jousting!*

*I take no responsibility for calculations.

[Peelee]

My worries are mostly for the people and houses below. Car accidents are already ugly, a still car falling from 500m into your roof would hit with 6 million joules: that's like being hit 30 thousand times while jousting!*

*I take no responsibility for calculations.

Are you saying jousting in joules means you're jostled?

[Mechalich]

Have you ever been on the side of the road with a car that wouldn't work? With a flying car, you'd have fallen to earth -- in a vehicle filled with explosive liquid.

If the car is electrically powered then the explosive liquid part is eliminated, and there's no reason why flying cars can't be fitted with vehicular parachutes in the same way as small planes.

[Gnoman]

Batteries still store enormous amounts of energy. Any battery with enough juice to power a "flying car" would be no less of a hazard than a tank of gas.

[veti]

The real problem with flying cars, if all the technical and cost and energy and safety issues could be magicked away, would be exactly the same as the problem with regular cars:

By the time I can afford one, there'd be no way to prevent every other... road user from having them as well.

And so all the problems we now have with congestion, pollution and parking - would still apply.

[factotum]

Batteries still store enormous amounts of energy. Any battery with enough juice to power a "flying car" would be no less of a hazard than a tank of gas.

And would also be enormously heavy and have very little range. Drones can fly on battery power for ages because they're very small, something big enough to carry even one person would be far bigger, heavier, and require lots more power.

[deuterio12]

The real problem with flying cars, if all the technical and cost and energy and safety issues could be magicked away, would be exactly the same as the problem with regular cars:

By the time I can afford one, there'd be no way to prevent every other... road user from having them as well.

And so all the problems we now have with congestion, pollution and parking - would still apply.

Not all of them. Some would be solved. Like peons and flying cars don't need to share the same plane of movement, so pepple on foot would not need to worry (so much) about flying car movement.

Also parking lots would be on top of buildings like for helicopters.

Plus when moving in 3D there's a lot more open space so congestion would go down. With our current tech it shouldn't be too hard to design an onboard AI that helps navigate the flying car and avoid collisions in the air.

Like already pointed out helicopters already existed and work relatively fine inside cities.

Main limiting factor is really that flying vehicles are still very expensive both upfront and in maintenance terms. There'll be need to be some sort of technological revolution to make them affordable for commoners.

[Malphegor]

Possible? Yes. Economically viable? Quite a while off. Laws changing to adjust to changes in tech? Very slow.

My favourite is the Airbus one from a year or two ago- a massive drone comes by, hooks onto the car, the body of the car lifts off while the actual engine and whatnot drives back to a central depot on its own, and the drone takes the car to its nest to feed to car chicks I assume.

[Liquor Box]

Yes they are. Humans are innately bad at driving ground cars, 1/7500 have a lethal accident annually and 1/5 of us have an accident in that time. If you have flying cars and they were exactly as easy to drive 1/5 of our adult population would die annually (there are no good accidents while flying.)

We aren't build for three dimensional movement, so we would be worse at driving flying cars. That means that more then 1/5 of us would kill ourselves annually, making it the single most lethal thing in the world. Flying cars won't happen.

I don't agree.

If flying cars were equally easy to drive as ground cars, we may have far fewer accidents in flying cars because there are far fewer obstacles to fly into (perhaps only other flying vehicles depending on the altitude you fly at).

Also, I'm not sure about your stats. This article suggests that an average driver will have an accident once every 17.9 years:
https://www.forbes.com/sites/moneybu.../#6418be7f4e62

That's sufficient to file for insurance. I could envisage a flying vehicle having an accident bad enough to file for insurance, but not bad enough to cause it to fall from the sky (for example, hitting a bird).

[halfeye]

...

And so all the problems we now have with congestion, pollution and parking - would still apply.

Pollution maybe, parking certainly, but I wouldn't foresee congestion except at the parking sites, as being a problem at all. There is a lot more space in three dimensions than when you are stuck to the two and a bit on the ground.

Flying cars would have to be flown by autopilots, because human errors are too severe in aircraft, but so long as the didn't need a lot of clearance from other aircraft and aren't confined to very restricted routes, I don't see congestion as being that likely.

[Bohandas]

IIRC there was a company that produced a working prototype flying car a decade or two back but they never caught on because they cost more than a Rolls Royce, got worse gas mileage than a tank, and the FAA hated them

[Chen]

The congestion would probably come at the landing part (and the waiting for clearance to land). And takeoff. Just letting anyone takeoff and land anywhere they want is asking for even more trouble. I mean I'm looking at the packed parking lot outside now clearing out and am trying to envisage how you'd let people takeoff from here. All I'm seeing is piles of fiery wrecks or SUPER long queues.

[Tyndmyr]

Are flying cars even possible? I know that this question been asked before by so many people but I want an honest answer. This is 2019 going to 2020 and flying cars haven't been invented yet. So I need to know are flying card even possible?

Yes, in that it is sort of possible to drive a cessna on a highway.

This is probably less exciting than traditional science fiction images, but wings are honestly pretty important to flying. Still, you can definitely make a vehicle that both drives and flies at least somewhat. To do that, tradeoffs exist, and the better you make a vehicle at one, the worse you will probably make it at the other. Adding wings to a Civic would make it a more awkward Civic, and adding a nice suspension and four fat tires to a Cessna would make it a less good Cessna.

It might be cheaper to buy a decent used Cessna and a decent Civic than to attempt to mash them together. Not impossible, but a lot cheaper. Private planes already being fairly expensive by most people's standards, this is probably pretty important.

1. People are bad at flying, and it will never be safe to allow people without in depth training to fly or allow large numbers to fly in an area at the same time.

Meh, we're very good at killing ourselves with cars. The advantage of the sky is that it's largely empty space. There's quite literally more room for error.

Oh yes. "Well, I guess I'll just crash my car into an atomic plant".

They're rated to take hits from commercial aircraft, so that's probably one of the safest possible bits of infrastructure to hit with your small aircraft. Annoying for the workers, no doubt, but hardly a disaster.

The safety issues can be fixed. The money issues....eh. Even keeping a reliable car on the road takes a considerable portion of many folks' income.

[Bohandas]

The congestion would probably come at the landing part (and the waiting for clearance to land). And takeoff. Just letting anyone takeoff and land anywhere they want is asking for even more trouble. I mean I'm looking at the packed parking lot outside now clearing out and am trying to envisage how you'd let people takeoff from here. All I'm seeing is piles of fiery wrecks or SUPER long queues.

To be fair this would be mitigated by being able to leave directly from whatever level you're parked on

EDIT:
Of course, it could have been mitigated already by the same means WITHOUT flying cars if city road designers would just acknowledge the existence of the third dimension

[Mechalich]

Batteries still store enormous amounts of energy. Any battery with enough juice to power a "flying car" would be no less of a hazard than a tank of gas.

This is entirely untrue. Yes batteries store enormous amounts of energy, but that storage need not be volatile in the way that gasoline is. Also, the batteries needed to power a flying car already exist, since they're roughly the same ones used to power a Tesla.

And would also be enormously heavy and have very little range. Drones can fly on battery power for ages because they're very small, something big enough to carry even one person would be far bigger, heavier, and require lots more power.

The calculations really aren't as bad as all that. Low speed flight, actually, is not all that much more energetically expensive than driving down a road (in part because of internal combustion engine and tire efficiency issues). Electrical motors, likewise, are much smaller and more compact than an internal combustion engine. The latter spends a great deal of energy moving itself.

Yes flying cars would be light, probably one-seaters only to start, with limited ranges, but since real benefit of such a vehicle is to bypass congestion in commuting, that's not really a problem.

The congestion would probably come at the landing part (and the waiting for clearance to land). And takeoff. Just letting anyone takeoff and land anywhere they want is asking for even more trouble. I mean I'm looking at the packed parking lot outside now clearing out and am trying to envisage how you'd let people takeoff from here. All I'm seeing is piles of fiery wrecks or SUPER long queues.

The majority of current flying car concepts are VTOL in scope, so no runway is needed. Congestion could be a serious issue in certain high density areas - like Manhattan, which already has a helicopter saturation problem - but that's a long ways off.

[Peelee]

This is entirely untrue. Yes batteries store enormous amounts of energy, but that storage need not be volatile in the way that gasoline is. Also, the batteries needed to power a flying car already exist, since they're roughly the same ones used to power a Tesla.

How heavy are Tesla auto batteries? What's the maximum range? And finally, from that same battery, what do you think the maximum range would be if it was also responsible for making the car fly?

[factotum]

How heavy are Tesla auto batteries? What's the maximum range?

The original Tesla Model S has about 1200 pounds (550kg) of batteries, which can store 60kWh of energy and take the car to a claimed range of a bit over 200 miles. I don't know how that would translate to flying, though.

[jayem]

The original Tesla Model S has about 1200 pounds (550kg) of batteries, which can store 60kWh of energy and take the car to a claimed range of a bit over 200 miles. I don't know how that would translate to flying, though.

Octane is 12kWh/kilogram, obviously you don't get all of that. But at 25% efficiency that's still 3kWh/kG against 0.1kWh/kG.
However we are much better at building light electric engines than light explosion-based engines, so on short flights you win back a bit.

The battery 200kg lighter than the spitfire engine, which could put out 700kW. So if you can get the power out and build a light motor, that potentially gives you a headstart of about 6 minutes of fast flight.
At full speed and power that would be at least 60 miles, normal flight should be less intensive :), but taking off and landing will lose much of the time :(. If the batteries were twice as efficient you'd definitely have something with non-trivial loads and ranges.

The Camel engine is about a 1/3 of the weight, and puts out 100kW. So that's not long either, 12 minutes if you could build a weightless engine.

[Jay R]

Cars get 20-40 mpg (8.5 km/l). I found two websites in which one person calculated his helicopter mpg at 300/46 = 6.5 mpg (2.8 km/l). Another calculated 7.2 mpg (3.1 km/l).

So figure a flying car uses 3 to 6 times as much energy as a road car -- which means that its range (with the same size tank or battery) would be 1/6 to 1/3 that of a car.

To be fair this would be mitigated by being able to leave directly from whatever level you're parked on

There were about 7,000 helicopter takeoffs and landings at New York City's three airports last year (upo over 20% from last year) -- and there are lots of people upset that the congestion is too much.

Flying cars for ordinary people would change that to over a million.

EDIT:
Of course, it could have been mitigated already by the same means WITHOUT flying cars if city road designers would just acknowledge the existence of the third dimension

They "acknowledge" it. They also research it.

Bridges cost 2-5 times as much as roads -- at least. They aren't going to build more of them unless you can show an economic benefit worth that much. A City Council who proposed it would be voted out for trying to raise everybody's taxes that much.

In my city (Dallas, TX) there are a few 5-high highway interchanges -- but only where it's justified. And those were by far the most expensive part of the highway system.

People who study, plan, and build roads for a living have actually thought about roads more than amateurs have.

[wumpus]

Are flying cars even possible? I know that this question been asked before by so many people but I want an honest answer. This is 2019 going to 2020 and flying cars haven't been invented yet. So I need to know are flying card even possible?

I can't help but think a "flying car" is the 20th/21st centuries "mechanical horse". While it is quite possible to design a mechanical horse with modern technology, realistically you want a motorcycle if you want something to ride and a car if you want a "horseless carriage".

Similarly, if you want a "flying car", you will almost certainly need to attach wings (possibly not if the whole thing is a lifting body) and eventually admit that it is a plane. Presumably the whole problem is getting a plane that can easily taxi between takeoff/landing and parking locations, and fit in a garage. That's some pretty hard restrictions on a craft that has to be as light as possible. If you don't have wings you have choices like "jetpack-like range" (see above) and helicopter range issues (presumably done similar to a quad copter for safety).

And as far as "flying autonomous" (with passengers), consider the Boeing 737Max. Boeing built a 737 with overpowered engines in the "wrong" place (behind and away from the center of lift and center of mass) and tried to correct it with software. Even with "money is no object" hardware and onboard pilots (trained to fly "normal" 737s, the whole point was to not need special training for the new plane), they couldn't (and presumably still can't*) get the computer to respond like "a normal 737". I'm guessing an autonomous consumer flying vehicle (call it what you will) will be an even harder problem.

* I'm reasonably sure that they can get something safe. But they'd have to train the pilots on how to handle this new software, and Boeing would be on the hook for such training. Boeing would rather leave the planes on the ground than eat that cost. But that's a completely differed thread. The other issue is that "pilot training" really isn't a good option for consumer flying vehicles. Captain Murphy's (of Murphy's Law) actual law wasn't that "bad things happen if possible", but that if you give a human two possible ways to do something (one of which is wrong and unsafe) they will eventually do the thing that is wrong and unsafe. Oddly enough, Captain Murphy (USAF) was responsible for aircraft safety analysis...

[halfeye]

And as far as "flying autonomous" (with passengers), consider the Boeing 737Max.

They had a bug in the software. That happens. It was a one off, and it will be fixed soon, if it isn't already. It's nasty and killed some people, but like the square windows of the first Comet airliner, it was a one off mistake, and it won't stop passengers flying on aeroplanes.

There will be bugs in the software of some of the flying cars (or whatever they turn out to be), hopefully they will all be caught and fixed before anyone dies, but I suspect the odds are that they won't, but the number killed in any particular flying car accident is probably going to be a lot less that in the case of the 737Max.

[jayem]

Clearly the Indy reads the stick

[wumpus]

They had a bug in the software. That happens. It was a one off, and it will be fixed soon, if it isn't already. It's nasty and killed some people, but like the square windows of the first Comet airliner, it was a one off mistake, and it won't stop passengers flying on aeroplanes.

There will be bugs in the software of some of the flying cars (or whatever they turn out to be), hopefully they will all be caught and fixed before anyone dies, but I suspect the odds are that they won't, but the number killed in any particular flying car accident is probably going to be a lot less that in the case of the 737Max.

Note that FAA controlled software isn't like the code in your Android/iPhone/PC. It *has* to be a bug-free implementation of the spec. Each line needs to be justified (not necessarily in the comments, but on demand and considering how visible the investigation is I suspect that the FAA has demanded justification for every single line). Shipping buggy software would get Boeing in more trouble with the FAA than killing hundreds of (non-US) people.

Obviously there is a bug somewhere, but almost certainly the spec. And that the spec is buggy implies a much deeper error about how to control a 737 with an engine "that's too big and in the wrong place". This isn't something where you just fix a malloc/free pair or a bad pointer chase. And I still don't think they'll will make a 737Max fly enough "like a 737" to completely avoid training (and both the pilots and carriers will require a lot more convincing than me).

I'm guessing that "flying cars" will first appear in BRIC countries or other places with more money than regulations (oil states, perhaps). Then you could see buggy control logic in the flying cars (or more complete user control). If they came out in the US, it would be a turf battle between regulatory agencies and startups trying to work around regulation. The fact that Tesla can reprogram your Tesla's braking system over the internet (yes, they've pushed an update for ABS. And it needed it.) does not give me warm fuzzies for anything but FAA approved software development schemes for software that *needs* to work.

[Tyndmyr]

Octane is 12kWh/kilogram, obviously you don't get all of that. But at 25% efficiency that's still 3kWh/kG against 0.1kWh/kG.
However we are much better at building light electric engines than light explosion-based engines, so on short flights you win back a bit.

There are some scaling issues with going for small hops as well. Most batteries can only sustain being drained so rapidly without damage. Thus, you generally need a minimum quantity of batteries that is dependent on your power draw. Part of the reason the Tesla's batteries last is because of the quantity of them.

Building electric aircraft that carry people is quite challenging indeed.

If you want one, going gas is going to be a great deal easier.

[snowblizz]

Building electric aircraft that carry people is quite challenging indeed.

It's been done, but the performance isn't particularly good yet. It's a lot of battery weight for the carrying capacity. But that's still just a (small) private plane (those also exist), not a flying car as we understand the concept.


The "mechanical horse" comparison is apt. A "classic" flyingcar as envisioned simply doesn't work out on a societal level.

[Chen]

Note that FAA controlled software isn't like the code in your Android/iPhone/PC. It *has* to be a bug-free implementation of the spec. Each line needs to be justified (not necessarily in the comments, but on demand and considering how visible the investigation is I suspect that the FAA has demanded justification for every single line). Shipping buggy software would get Boeing in more trouble with the FAA than killing hundreds of (non-US) people.

Obviously there is a bug somewhere, but almost certainly the spec. And that the spec is buggy implies a much deeper error about how to control a 737 with an engine "that's too big and in the wrong place". This isn't something where you just fix a malloc/free pair or a bad pointer chase. And I still don't think they'll will make a 737Max fly enough "like a 737" to completely avoid training (and both the pilots and carriers will require a lot more convincing than me).

Yeah the 737Max issue wasn’t a software bug. The software did exactly what it was supposed to do. Its just that what it was supposed to do lacked a TON of robustness. Inadvertent activation of MCAS being initially categorized as a “Major” hazard rather than “Hazardous” or “Catastrophic” and the spec being changed later lead to the wrong system level architectural decisions (allowing a single AOA sensor to activate the mode with no cross-checks). Compounding on that, thinking the pilot override was sufficient to mitigate this hazard while also not providing additional training/documentation of this function, was probably the final nail in the coffin.

But these are failures well above the software level. The software is tested to its requirements and any deviation from these requirements needs to be understood and deemed acceptable. They almost certainly followed DO-178C processes so the software likely passed that fine. That doesn’t test whether what the software is doing makes sense at a system level; it just tests that the software does exactly what its requirements say it is supposed to do.

[Chronos]

The flying car was not invented 80 years ago, but 115. A couple of fellows named Wright-- Perhaps you've heard of them?

Some may object that that's not a "flying car", because it can't drive on roads. But why would you want to? If you have a vehicle that can fly, it's so you can fly. The whole point is to not use roads.

The real question is, why are so many people not satisfied with the flying cars we have? That's the question that bears digging into.

[hamishspence]

A plane is not a flying car.

The point of a flying car, is that in cases where flying to a location is impractical (no landing space near that location) - then you can drive to it instead, in the same vehicle.

A flying car is supposed to be able to fill the roles of small private plane, and regular car, simultaneously, with the same vehicle being capable of doing both jobs.