Passenger Drones (Concept of Mine)

[WestAir]

3 hours ago, RCgothic said:

I misremembered. I found the Google report, it's actually 17 seconds to respond to alerts and take back control. To actually react intelligently is another matter entirely.

The situation you describe sounds like a pilot with hands on anticipating the situation that they need to rectify. In an emergency whilst operating on automatic the manual operator may have been reading, snoozing, facing the wrong direction. They aren't going to have the situational awareness of an alert pilot anticipating that they're going to have 

Also 'often completed in less than five seconds' is not 'everyone completes in less than five seconds'.

I've never had the "luxury" of the AP turning off while I daydreamed about what I was going to do when I got home, but I like to imagine I'd be able to take full control in less than 5 seconds.

That said, what I'd like to think and the reality of the situation (as the article implies) are two different things. Thanks for the read.

[obsidian_x]

There's been numerous attempts to make flying cars/drones:

Most recent one I can think of is this:

Then there's the one Colin Furze built (in his "shed"):

 

Or these guys had plenty of hype a few years ago, but never seemed to be able to get the power density in batteries etc (as far as I can remember). Not sure if they even exist anymore.

You're definitely not the first person to think of it.  

Like many others have said, the issues are around reliability - a quad/octo-coptor will fall out of the sky in the event of a power failure, then there's the issue of single engine failures can bring the whole craft down, so you need redundancy and safety margins.  Noise would be another major issue.  How happy would your neigbours be with your arrival at 3am after a big night out etc, or the 5:30 am take off every day for your work commute.  Or would it be central locations you take off and land at, then use ground transport for the last mile?

[Red Iron Crown]

12 hours ago, ZooNamedGames said:

Why not use the engine from a Cessna? It's existing reliable technology, we'd just be flipping it 90 up. It would fit the "withered technology" definition as Nintendo meant it.

For your amusement try calculating the TWR of a Cessna. It's not going to VTOL.

I don't think control is a huge issue with flying cars, autopilot is very mature and we could likely see a net improvement in air safety by removing pilots from the loop if it was socially acceptable. It would be trivial to beat automotive safety numbers.

Liability issues are a big thing that can't be ignored, it would have to be established who pays for what in a predictable manner if insurance companies are going to underwrite these (and you need insurers for this idea to fly).

But the biggest issues are noise, efficiency, and available landing sites. It's not possible to make a heavier-than-air VTOL that doesn't move a ton of air, and moving that air will always make noise and potentially damage the surroundings. So you'd need somewhat specialized landing sites that are kept free of debris, and in a dense environment like a city you'd need an awful lot of them, too. Efficiency will always be worse than an equivalent tech ground vehicle, because it has to do the work of maintaining speed and altitude versus maintaining speed alone.

If we step back a bit, is this really the direction we want to be going anyway? Do we want to trade the suburban sprawl that was enabled by good roads and cheap cars for subsuburban sprawl where people are commuting hundreds of km a day? Do we want to replace our relatively clean and efficient cars with something more energy intensive, with all the environmental footprint increase that implies?

Personally, I've put the personal flying car in the "neat, but impractical" category a long time ago. Maybe we'll see some in the high end luxury market, but even there people are better served by cars + private aircraft.

[Kryten]

8 minutes ago, Red Iron Crown said:

Personally, I've put the personal flying car in the "neat, but impractical" category a long time ago. Maybe we'll see some in the high end luxury market, but even there people are better served by cars + private aircraft.

I don't really think even anything 'neat' about the idea when you get down to it, it's essentially a brief for 'a helicopter but worse'.

[Nuke]

most successful one ive seen is this one. it at least appears as if it is somewhat controllable.

this is an 8 engine monster, i assume its using servo controlled throttles and a good flight computer. its a little top heavy so its kind of a death trap.

im wondering if it wouldn't be better to do a gas-electric configuration, with a couple apus providing the juice and a bunch of brushless motors. multi-engine configs without heavy cross shafts will never be accepted by faa standards. but redundant apus and multiple redundant ultra-reliable brushless motors might work well. should be able to survive the loss of an apu or 3 motor/prop failures. not requiring runways would certainly make it easy to set down if there was a problem.

[wumpus]

2 hours ago, Red Iron Crown said:

For your amusement try calculating the TWR of a Cessna. It's not going to VTOL.

I'm pretty sure you could substitute a corvette (LS3/LT1) engine reasonably well.  VTOL power (for sufficiently light aircraft) and similar power over long stretches (Lemons* data implies that hacking the autopilot to allow hundreds of horsepower for long periods will kill the engine fast, at least without expensive upgrades).  More likely you would just use electric motors** and draw from a capacitor (or more likely an Fe-ion battery) for takeoff landing and a generator (or Li-based battery).

* The race, not cars brought for repair multiple times.  The few times teams who managed to bring in worn LS1 engines did not work well (with the implications that it was the engine), implying that such engines really can't be expected to run close to the "hundreds of horsepower for hours" that naive plane makers hope for (I'm pretty sure that homebuilt plane makers found this out a much harder way than the lemons teams, I just haven't seen the data).

** I'd certainly expect the innovation for this type of thing to happen in China and/or India.  Basically somewhere that doesn't have an "FAA" with very ossified views as what an aircraft is and how to regulate it.  The bit with multiple motors is to avoid the requirement for a "multi-engine" pilot's license while still having redundancy (that and electric engines don't suffer such ghastly inefficiency when running at less than 50% power).

[ZooNamedGames]

2 hours ago, Red Iron Crown said:

For your amusement try calculating the TWR of a Cessna. It's not going to VTOL.

I don't think control is a huge issue with flying cars, autopilot is very mature and we could likely see a net improvement in air safety by removing pilots from the loop if it was socially acceptable. It would be trivial to beat automotive safety numbers.

Liability issues are a big thing that can't be ignored, it would have to be established who pays for what in a predictable manner if insurance companies are going to underwrite these (and you need insurers for this idea to fly).

But the biggest issues are noise, efficiency, and available landing sites. It's not possible to make a heavier-than-air VTOL that doesn't move a ton of air, and moving that air will always make noise and potentially damage the surroundings. So you'd need somewhat specialized landing sites that are kept free of debris, and in a dense environment like a city you'd need an awful lot of them, too. Efficiency will always be worse than an equivalent tech ground vehicle, because it has to do the work of maintaining speed and altitude versus maintaining speed alone.

If we step back a bit, is this really the direction we want to be going anyway? Do we want to trade the suburban sprawl that was enabled by good roads and cheap cars for subsuburban sprawl where people are commuting hundreds of km a day? Do we want to replace our relatively clean and efficient cars with something more energy intensive, with all the environmental footprint increase that implies?

Personally, I've put the personal flying car in the "neat, but impractical" category a long time ago. Maybe we'll see some in the high end luxury market, but even there people are better served by cars + private aircraft.

We want to upgrade. Personally the idea of living in this world as it is with cars is cool for 2000, but in 2040, I think we should have more. 

[Red Iron Crown]

4 minutes ago, wumpus said:

I'm pretty sure you could substitute a corvette (LS3/LT1) engine reasonably well.  VTOL power (for sufficiently light aircraft) and similar power over long stretches (Lemons* data implies that hacking the autopilot to allow hundreds of horsepower for long periods will kill the engine fast, at least without expensive upgrades).  More likely you would just use electric motors** and draw from a capacitor (or more likely an Fe-ion battery) for takeoff landing and a generator (or Li-based battery).

Piston powered VTOLs are certainly possible (there are piston powered helicopters, for instance). We're still faced with the problem of it being inherently less efficient than ground transport.

2 minutes ago, ZooNamedGames said:

We want to upgrade. Personally the idea of living in this world as it is with cars is cool for 2000, but in 2040, I think we should have more. 

I'm afraid you're going to be disappointed. We're rapidly exiting the golden age of cheap energy where we ignore the repercussions and the sooner we do, the better. 

[ZooNamedGames]

Just now, Red Iron Crown said:

Piston powered VTOLs are certainly possible (there are piston powered helicopters, for instance). We're still faced with the problem of it being inherently less efficient than ground transport.

I'm afraid you're going to be disappointed. We're rapidly exiting the golden age of cheap energy where we ignore the repercussions and the sooner we do, the better. 

Hydrogen power is very effective... Available and works. So... How wouldn't this work better?

[Red Iron Crown]

Just now, ZooNamedGames said:

Hydrogen power is very effective... Available and works. So... How wouldn't this work better?

Not enough energy density for sustained flight.

[ZooNamedGames]

11 minutes ago, Red Iron Crown said:

Not enough energy density for sustained flight.

Yet enough to propell this to orbit? Ok... I see.

[Red Iron Crown]

Just now, ZooNamedGames said:

Yet enough to propell this to orbit? Ok... I see.

It's getting harder and harder to take you seriously, honestly. That has a burn time of under ten minutes, is ~90% propellant by mass, drops stages like it's nobody's business, has no provision for remaining in a fueled state for any significant period of time, and uses rocket engines which offer the highest TWR of any engine type. Do you see why these properties are not compatible with a consumer vehicle? Are you really proposing hydrolox rocket engines for a flying car?

[razark]

27 minutes ago, Red Iron Crown said:

Are you really proposing hydrolox rocket engines for a flying car?

It does offer a novel solution to overpopulated areas, though.  Really would reduce traffic problems.

Edited July 27, 2016 by razark

[ZooNamedGames]

20 minutes ago, Red Iron Crown said:

It's getting harder and harder to take you seriously, honestly. That has a burn time of under ten minutes, is ~90% propellant by mass, drops stages like it's nobody's business, has no provision for remaining in a fueled state for any significant period of time, and uses rocket engines which offer the highest TWR of any engine type. Do you see why these properties are not compatible with a consumer vehicle? Are you really proposing hydrolox rocket engines for a flying car?

You do realize those who made fantastic historical ideas were mad men in their time? Copernicus claiming that the sun was the center rather than Earth. Or that the Earth was round rather than flat, Aristotle. That all living things are made of tiny organisms called cells, Hooke; or that you can split the basic building blocks of everything, Einstien. These people were thought of as idiots and morons by their community yet it's them who made the accomplishments... not those who thought they knew everything.

Just because something doesn't seem logical doesn't mean you should kick it out on it's face.

[KSK]

Hydrogen power is great if you can a) produce it in an environmentally benign manner and b) figure out a way to store it.

Going back five years or so when the 'hydrogen economy' was the latest buzzword, most hydrogen was produced by steam reforming natural gas. Which kind of defeated the main selling point of hydrogen power and probably wouldn't be an option anyway in the scenario Red Iron Crown had in mind. Although you could, in principle, produce hydrogen by electrolysis using some form of non-fossil fuel reliant energy source to power your electrolyser. It would be expensive but if there wasn't a sensible alternative it would happen.

Storage is the killer though. You've basically got a choice between conventional high pressure gas cylinders which are heavy and don't hold much hydrogen for their weight; cryogenic storage in (presumably) adequately insulated tanks, which still don't hold a great deal of hydrogen for their size; some fancy physisorption or chemisorption technology where you try and store hydrogen in the gaps in another molecular structure. Think intercalation electrodes for lithium ion batteries but intercalating hydrogen rather than lithium.

In other words you've got a choice between two lousy solutions and one - so far - theoretical solution that hasn't, as far as I know, made it past the 'interesting demo' stage. Frankly, the best way of storing hydrogen would be to convert it into hydrocarbons.

Edited July 27, 2016 by KSK

[Kryten]

26 minutes ago, ZooNamedGames said:

You do realize those who made fantastic historical ideas were mad men in their time? Copernicus claiming that the sun was the center rather than Earth. Or that the Earth was round rather than flat, Aristotle. That all living things are made of tiny organisms called cells, Hooke; or that you can split the basic building blocks of everything, Einstien. These people were thought of as idiots and morons by their community yet it's them who made the accomplishments... not those who thought they knew everything.

Just because something doesn't seem logical doesn't mean you should kick it out on it's face.

 You aren't somebody with a fantastic idea, you're probably back thousands in line from the first person to have some version of this idea. More than one of those people made it to the prototype stage, as has already been pointed out, and still failed miserably. If you have something that really distinguishes you from all the earlier would-be-inventors, then tell us what it is instead of babbling about Galileo.

[ZooNamedGames]

2 minutes ago, Kryten said:

 You aren't somebody with a fantastic idea, you're probably back thousands in line from the first person to have some version of this idea. More than one of those people made it to the prototype stage, as has already been pointed out, and still failed miserably. If you have something that really distinguishes you from all the earlier would-be-inventors, then tell us what it is instead of babbling about Galileo.

My only limitation between the rest of the idiot herd is money. The same issue that will lead our species into destruction.

[Kryten]

1 minute ago, ZooNamedGames said:

My only limitation between the rest of the idiot herd is money. The same issue that will lead our species into destruction.

If you seriously think you can design some revolutionary transport system, then design it and then go drum up some venture capital.

[ZooNamedGames]

Just now, Kryten said:

If you seriously think you can design some revolutionary transport system, then design it and then go drum up some venture capital.

I'd love to; but the people who would fund it want money from it. How can I, a 18yo high school student manage to get any benefit for an idea when I have nothing to prove it's worth?

[Kryten]

If you really can design some super-efficient flying machine, and it would need to be super-efficient to be economically viable in the niche you're talking about, it shouldn't be too hard to get somebody else to double-check your calculations. If literally all you have is an idea, there's no reason for anybody to give you anything.

[ZooNamedGames]

3 minutes ago, Kryten said:

If you really can design some super-efficient flying machine, and it would need to be super-efficient to be economically viable in the niche you're talking about, it shouldn't be too hard to get somebody else to double-check your calculations. If literally all you have is an idea, there's no reason for anybody to give you anything.

Which is the problem. Someone has a possible solution but since it's only an idea no one to test it. Who knows; someone could've thought of the solution to everything but because it's some old hobo's idea we disregard it and tell him to work his wages.

I see.

[Kryten]

 You haven't demonstrated that you even have an idea that's any better than what e.g. Paul Moller has been chasing for forty years.

[ZooNamedGames]

1 minute ago, Kryten said:

 You haven't demonstrated that you even have an idea that's any better than what e.g. Paul Moller has been chasing for forty years.

How am I supposed to with no budget?

[Kryten]

You design and you make calculations. Engineering without calculations is basically just an unsubstantiated opinion.

[KSK]

1 hour ago, ZooNamedGames said:

I'd love to; but the people who would fund it want money from it. How can I, a 18yo high school student manage to get any benefit for an idea when I have nothing to prove it's worth?

Plenty of ways. One of the easiest might be to go to college (assuming you're not already) and speak to your technology transfer office. They should be able to help you, or if they're not willing to help you directly, to give you some advice and put you in touch with the right kinds of people to speak to if you want to try and make a go of your idea yourself. 

Yes, you'll need investment. Yes those investors will want to see a return on that investment. Unless you plan to start making these things in your garage, that's the way the world works. Your investors will essentially be taking on all the risk involved in bringing your idea to market and they're going to want appropriate compensation for doing so. On the other hand it's not like people never got rich by having VCs invest in their companies.

Before doing anything though, I'd recommend putting a business plan together. Taking a long hard look at some of the questions on this thread - and coming up with realistic answers, rather than just 'rule of cool' handwaving - would be a good start. If nothing else that will tell you whether you really want to be dumping all your time and energy into this project.