Aeromobil: Roadable aircraft
aeromobil.com
aeromobil.com
Every single one I've seen is neither a particularly good airplane nor a particularly good car, and they're expensive. For the price of one, you can generally buy a better car, a better airplane, and a second better car to keep at your most frequent destination airport, and have enough money left over to rent cars at other destinations for years.
I can't find a price on this one, but I suspect it will be no different.
If you want a light plane, buy a light plane. There are plenty of them out there, with a large variety. If you want a car, buy a car. Lots of reasonably priced choices there. I just don't see why anyone would ever want a single vehicle for both roles.
Things change. Anything could be the Apple Newton of the next big thing :). (Although to be honest, I see transportation moving much more to a computer controlled system rather than this, but just for the sake of argument).
If you've already lost the time saved by not switching from car to aircraft a minute or two into the flight it's not that practical except in situations where there's absolutely no chance of getting a taxi or hire vehicle at the end. Suffice to say it isn't going to be a cheap solution to that relatively rare problem.
1st) "fundamental laws of physics rather than moore's law" is a great analogy since people over time have continually cited physics as what will stop Moore's law. Some argue that it has in recent years done just that.
2nd) Like smartphones, the technology to build flying cars has evolved and will continue to evolve. I'm not an expert on aircraft or cars, but I can think of some areas that will make this easier right away. A) by moving all controls to fly/drive by wire, we can reduce weight, B) Materials technology has improved dramtically. C) Battery technology has improved. Maybe not for flying, but for systems. D) Weight can be further reduced by having all controls in one small computer which will eventually be the size of a smart phone instead of the size of a desktop, E) Fuel economy is improving in both cars and airplanes.
But... Here is what I think can really make it happen, and what will make it happen. When cars and planes can both fly themselves with full automatition from point to point without pilot intervention, we will see flying cars. The reason stems from the fundamental problem that 99% of people don't know how to fly, and of those that do, only a small percentage can fly, afford and want to own a car/plane.
I don't know anyone who wouldn't be interested in hoping in a fully automated vehicle which would fly them from point to point at 500 mph. You could work 250 miles away from where you live.
It will happen, just not for a long time.
There is, I would argue, no situation where a roadable airplane is better than a normal airplane plus a car. It doesn't have to be better than both in all cases, but it has to be better than both for something.
For a smartphone, that "something" is extreme portability while still providing some computer functionality. A phone+computer doesn't let you reasonably read your e-mail while standing on a bun, for example.
I've yet to see any similar case for "flying cars".
http://en.wikipedia.org/wiki/Smartphone#History
They were shitty "computers" and very expensive phones. People had been predicting that they would happen for the longest time, and until the iPhone it pretty much seemed like nothing more than a geek dream.
Regarding the roadable car - I can imagine a fantastic use-case for commuters [on okay-weather days]. Let's say you want to live 100 miles from Boston or SF but would be looking at a brutal morning commute. But if some future-model was safe/fast/efficient/less expensive and there was infrastructure to land, all of a sudden you have a real use case.
Now the one in this video looks positively dangerous. But it doesn't mean down the road there can't be one that flies completely autonomously in most weather and can land on short runways in convenient locations in the middle of a city - that you can just drive off into a parking spot. Maybe it starts by costing as much as a tesla roadster.
I don't imagine any of this will actually happen, but if somebody can get you a roadable airplane for $100,000 that flies itself, it becomes a lot more interesting.
But phones were getting smaller, and more featureful year after year so it made sense to make that prediction.
No similar trend exists in planes/cars that I know of.
Let me give you some concrete examples: You want an airplane to be light, have good impact protection from the front (because airplanes very rarely get run into by a mountain from behind), and not require long runways. A car, on the other hand, must have good impact protection from all sides, fit inside a lane on the road, and good acceleration so you can merge onto the freeway.
The second car requirement and last airplane requirement together necessitate folding wings, which are heavier than fixed wings (and also more complicated and more expensive). Short of a powered-lift design (which is going to be even more insanely expensive), there is no other way around the physics. It doesn't matter how good your engineers are. Physics puts limits on what you can do with a wing.
The side and rear impact protection on a car do nothing beneficial to the airplane, but add weight. Again, clever engineering can only do so much within the limits of physics with regard to material strength. I don't care if you use the most expensive quantum-dot-infused titanium-nanotubes: Real-world materials have strength limits.
As part of making an airplane light, you're probably going to want to put a small, air-cooled engine in it (the Rotax 912, used in the linked aircar, produces between about 90 and 110 HP, depending on the variant). Even a light car is going to have very poor acceleration with that engine. Again, this is a matter of physics: F=ma. Some sort of continuously-variable transmission will help a bit, but you still only have 110 HP to work with.
Smartphones have improved radically over the past 10 years because the problem was not physics, but rather engineering. Software engineers made better software (which is really what made the iPhone different from Blackberries when it was introduced) and hardware engineers made better CPUs to run the software at a decent speed.
That being said, I think it's a very exciting vision with practical application. If you're a business traveler, why bother with the whole airplane + taxi or rental car system if you can stay in the same vehicle? I envision a small runway where dozens of these vehicles can take off in a very short time span from each other, being on their way. Of course aerial navigation, safety and all that will be issues that need to be overcome, but I definitely see this as being feasible (here's an idea, why not have them be self-driving AND self-flying?).
How does staying in the same vehicle help? Is it really that big of a deal to move between your car and your airplane?
Let's not forget that airplanes need a preflight inspection before you fly if you're not suicidal, and having just driven the airplane to the airport doesn't eliminate that need. Quite the contrary: being exposed to the stresses of driving will increase the need for a preflight inspection.
The time-consuming non-flying activities for an airplane are preflight inspection, flight planning, clearances, etc. A roadable airplane does nothing at all to help this.
Maybe you save two or three minutes out of your half-hour preflight activities. Whoopdedo. Meanwhile, you make up more than that lost time because your dedicated airplane is a better and faster airplane than the crazy "flying car".
Sometimes you're really just better off having separate objects doing what they do best. I don't see any push for amphibious cars, for example. Everybody seems to have accepted that you're better off buying a car and a boat separately. But somehow there's an obsession with airplane/cars. I blame The Jetsons.
I could be wrong, but I'm going to need someone to give me some sort of actual advantage to one of these things before I might think I am. It doesn't save you time, it doesn't save you money, so what's the point?
Also you don't need a flight plan, that is completely optional (it is essentially a SAR service if you crash). With modern avionics you can dynamically recalculate flight paths on the fly in the cockpit.
You really don't need clearances either, unless flying into class B airspace (which you don't really want to do that with a small plane anyways). You can fly across the country without ever telling anyone.
Also having separate planes and cars has real disadvantages. What about when you arrive at the destination? You always have to rent a car. Not only that you have to store the plane which can be quite expensive. There are many advantages to this.
You absolutely need a flight plan. You do not need to file a flight plan, but you still need a plan. You need to know where you're going, how far it is, what the weather is like, what the weather is going to be like over the course of your trip, what your alternates are, what NOTAMs are in effect, etc. This step is, again, not optional if you enjoy living.
The price premium of these roadable airplanes will pay for decades of hangar rent and car rental, no exaggeration, so I don't see either of those as a disadvantage.
Not saying this won't have a practical purpose, but I'm not convinced business travel will be one of them. I'm thinking tesla roadster, it's a cool and expensive toy until new tech is developed that allows for more passengers, longer range, and more convenient takeoff/landing sites.
Terrafugia Transition, new: $279,000
Cessna 172 Skyhawk, new: $289,500
The Transition only seats two while the 172 seats four, but I'd personally rather have the plane that also drives.
Or, you could compare the Terrafugia to a two-seat LSA. That would be a fairer comparison, since the Transition is an LSA while the 172 is a real certified airplane. Pipistrel and Icon both sell LSAs for about half the price of a Transition.
There's no reason to only examine new aircraft, but even if you insist on that, you can do vastly better. For example, a Pipistrel Sinus will set you back about $86,000:
http://www.aviationbull.com/sinus
Compared to the Terrafugia, you can buy that, plus two $30,000 cars, and still have $133,000 left over to rent more cars. Or, say, buy a house. The Sinus also carries more weight, flies faster, burns less fuel, has a better range, and requires vastly less runway.
It's also probably substantially safer in the event of an engine failure. I don't see a glide ratio listed for the Transition, but just from looking at its relatively large frontal area, low-aspect-ratio wings, and gigantic road-sized front wheels exposed to the air with naked struts, I'd guess it's probably in the Cessna range of 10 or under. The Sinus has a glide ratio of 27, meaning you can get quite far to an airport if the engine quits. It's actually a decently performing glider in addition to a regular airplane.
If you expand the search to used aircraft, you can get quite cheap. For example, Cessna 152s in decent shape can be had for under $40,000, and that's not even the cheapest option.
Make that one hour commute a lovely fifteen minute flight!
But that can't actually happen. The month of driving practice needed to get a license becomes a year or more of pilot school. The damage inflicted by motor vehicle accidents is already horrendous enough without adding a thousand meters of altitude into the equation.
If I were designing a road/air vehicle. It would be a motorcycle with detachable wings/prop.
For my personal definition this complete works. But I have no clue which of us is more representative of the public…
However, I think people should refrain from making a business out of this. Use research funds to push boundaries! I can't help but look at this page and video and think that they are trying to make money off of it.
Speaking as a pilot, a lot of aircraft are built with crashing in mind. Just look at the 777 crash at SFO recently. Judging this craft simply by the video, I have serious doubts that this craft would keep you very safe in an air emergency. I'd love to see what its glide ratio is.
Another issue with current road->air systems is the need of 2 powerplants: one for the road and one for the air. For road travel, the extra weight is not that big of an issue. However, the weight of the road engine (batteries if it were electric) puts serious limitations on its airworthiness and stability.
Let's put pen to paper and figure this out.
The cost of an aero car is likely to be in the $300K range. This does not include maintenance, insurance (insurance!) and other operating costs.
Well, to put it in very simple terms, with $300k you can buy a nicely equipped Tesla AND an equivalent Cessna and still have up to $200k left in the bank --depending on the airplane cost which starts $10K.
Going this route means that you'll have ZERO FUEL COSTS while on the road and a dedicated aircraft that is well-tested, proven and with a history of millions of flight miles.
But, wait! You can rent an aircraft for somewhere in the $75 to $250 per hour range. No jets. I am looking at Cessna 152 to 182 class aircraft. The aerocars are roughly equivalent to the low end of the Cessna range.
If you buy a Tesla and rent aircraft you have zero on-ground fuel costs as well as over $200K in the bank. Depending on the model you rent you have enough money for over 2,500 hours of rentals. You also have zero aircraft maintenance and operating costs. If you play it right 100% of the rental costs are tax deductible.
It is important to note that this also gives you aircraft at every airport in the world where such aircraft are rented. This beats owning a plane by a massive margin.
But, wait! How much do you really fly per year. Really?
Nah, these things are bad ideas. Interesting from an engineering perpective.
Maybe Tesla should market a flying car deal: buy a Tesla and the fuel you'll save will buy you several domestic flights per month. Maybe they can make a deal with flight schools to get people certified at a discount and then they can rent planes at a discount as well.
Again, I have to wonder who invests in these things. I remember reading about one that got some $40 million from investors. Learn to use a friggin calculator.
From that, we can deduce that it has a 37.5 l fuel capacity.
Now let's look at the specs for plane mode. It says that it has a range of 700 km, and consumes 15 l per hour. At 15 l per hour, it would take 2.5 hours to go through 37.5 l, but to go 700 km in 2.5 hours takes an average speed of 280 km/hour. The specs say that the top speed is 200 km/hour, so what is going on? (They do say "and more" for the top speed, but I would not expect the listed speed to that far under the real top speed).
There's no reason that this couldn't be certified as a LSA (http://en.wikipedia.org/wiki/Light-sport_aircraft).
We have already countless idiots on the roads, I don't want them in the air as well; I'd be afraid to get out of my house.
But competition is always good!