Flying car closes in on FAA OK
bostonherald.com
bostonherald.com
That old joke about "where are the flying cars? Have you ever heard of airplanes" misses the essential dream: To go into your garage, hop in your car and lift off and go wherever. That's the flying car. Sadly, unless we make some strides in the direction of gravitational manipulation or fusion drives, I'm not sure that'll ever be a reality.
Still not an easy problem. Closest is probably the doomed Moller Skycar. Once we have self-driving land-based cars (and widespread mainstream acceptance of them), a lot will open up since we could relieve the burden of human control.
Granted, I was just in an accident a few weeks ago, and it dramatically changed my view on driving altogether. Crashes aren't just something that happens "to someone else". People are very irresponsible, reckless, and impatient when it comes to moving vehicles.
Once you have an airplane that's as easy to fly as a car is to drive, you can do all of what you're talking about, and there's no reason to combine it with something that can drive it on a highway. It's not that big of a hassle to switch vehicles at the airport.
As far as licensing, you still need (in the US) to get a Light Sport certificate, which is most certainly a higher bar than a drivers license.
I agree that the Light Sport standards lower the bar for pilot and airplane certification, and that the result is great for general aviation. But lets not pretend that this airplane plays a big role there.
In short, the one thing about the "flying car" concept that's interesting in the real world is making the things easier to fly. This "flying car" misses that one thing.
It looks a little fragile to perform well as a car. I imagine a significant pot hole might be enough to damage the skin. I understand the need to be light and aerodynamic so that it is flight-worthy, but this looks more like a toy then a real solution. It reminds me of those cars that can also perform as a boat -- they do neither well, their remarkable feature is that they do both.
Many people seem to think "flying car" == "I can just launch and avoid all the rush hour traffic, and then land in my driveway". The reality of course is far different, you have to drive this to/from an airport.
I'm curious what problem this is intended to solve.
We (staff of the Museum of Flight) said the same thing about Moulton Taylor's Aerocar [0]. It doesn't do either thing very well, and that's a big reason there hasn't been a hugely successful product in the space yet.
That said, it does solve a specific problem: it cuts significant time off for those who regularly make trips in the hundreds of miles, particularly between semi-remote locations.
Imagine you lived in central Kansas, and had radio transmitters, oil fields, or clients spread all across the state. You could fly from small airport to small airport [1] in considerably less time than it would take to drive, and then have a car available to drive out to your destination.
One of the advantages this variant has over other past attempts is that it's classified under the (new) "Light Sport Aircraft" category [2]. It's much easier to get a LSA license than a normal pilots license, among other things.
[0] http://www.museumofflight.org/aircraft/taylor-aerocar-iii
[1] http://www.filmkansas.com/pages/airports - map of KS airports
Setting your own schedule would certainly be beneficial, but it would take a long time to justify that cost.
BTW, do you still have the B-17 out front?
Of course. Most aircraft are significant investments; you don't drop that kind of money unless you've got really good reason.
That said, if you're one of the few for whom this particular use case is relevant, I can't think of a viable substitute. If you try to use a traditional aircraft, you're left needing ground transportation at various remote sites that may not have taxis. If you drive from site to site, you might end up spending an extra 3-5 hours on the road every day. So if you're running a high-revenue business that requires a high amount of travel, this (or some other flying car) might be a game-changer.
> "do you still have the B-17 out front?"
I stopped working there when my son was born, and left the state a year and a half ago. This is the first I've heard of the B-17 being out of its hangar, but apparently it's open for summer tours:
Surprising to see max speed is 115 mph, for some reason I thought it would be much higher.
So a drop in mpg is completely understandable
Also, there is a lot more causing drag (the wings at least) when it is flying vs when it is on the ground
I may be completely wrong, the concept of lift never made sense to me. It always seemed like free energy.
Airplanes generate only forward thrust (unless you're in a VTOL craft which we won't talk about). This forward force is what ends up generating lift due mainly to two particular, but separate, applications of physics.
First, wings take advantage of what is called Bernoulli's principle. Picture a wing: it is longer on top than it is on bottom due to the "chamber" of the wing. I.e., the asymmetric difference in the shape of the top and bottom of the wing. This causes the air that flows over the wing on top to be at a different speed than the air on bottom, since the air on top gets compressed. (Remember that in a river, if the river narrows, the current speeds up because you still have a stable amount of water to get downstream. If the volume status the same, higher pressure = higher speed, roughly.)
So, by Bernoulli's principle, the slower air on bottom has more potential energy than the air on top -- and that results in more outward pressure by the air, i.e., it pushes up on the wing harder than the air on top pushes down (which has more kinetic energy and less potential, due to the higher speed). Because the wing is not creating energy, the air is merely converting to and from kinetic/potential.
However, that's not the entire story of lift!
Wings are also angled, with their trailing edge down as compared to the leading edge. This angle is defined as the "angle of attack". Think about it like this: when you stick your hand out of the window of your car while driving down the freeway at high speed, you can tilt your hand up and "take off". The wind hitting your hand pushes it up because of the angle. This seems kind of straightforward, right?
If you continue tilting your hand closer and closer to the vertical, at some point it falls back down. You have "stalled" and are no longer generating enough lift to fly. Airplanes do the same thing, so they have to balance the lift they generate with the other factors.
Airplanes fly mainly through the combination of these two things: lift generated by the relative difference in airspeed above and below the wing, plus lift generated by the angle of attack.
I hope that is explanatory, and if I'm wrong on anything, someone else will come correct me!
The speed difference being due to asymmetry is wrong. Symmetric wings still generate lift by having air flow over the top faster than the bottom. Symmetric wings flying upside down also still generate lift that way. Asymmetry helps, but is not necessary.
The important thing to understand about aerodynamic lift, and that few people do understand, is that the Bernoulli's principle action and the air deflection action are the same thing. They are not two different mechanisms which act in concert. They are two different ways of looking at a single phenomenon.
If you deflect air downwards, you will generate a speed and pressure differential between the top and bottom of your wing. The pressure differential will produce an upward force on the wing that is precisely equal to the downward force on the air. Likewise, if you generate a pressure differential between the top and bottom of the wing, you will deflect air downwards. They're two different results of the same action.
To truly understand why wings generate lift (which is the same thing as why wings generate a faster airflow over the top than the bottom, or why wings generate a lower pressure on top than on the bottom, or why wings deflect air downwards), you need to understand the Kutta condition.
A wing moving through air has two stagnation points, which where the airflow splits. There's a stagnation point at the front of the wing. Any air above that point goes over the top, and any air below that point goes underneath. At the back of the wing, the stagnation point is the point where the air from the top and bottom meet again.
The location of the front stagnation point depends on the angle of attack. If the wing is flat, the front stagnation point will be right at the leading edge. As you tilt the wing upwards, the front stagnation point moves toward the underside of the wing.
The Kutta condition says, in short, that air won't go around a sharp corner. Thus, the rear stagnation point is always at the trailing edge of the wing. This is why wings are shaped like a teardrop, and that sharp edge at the back keeps the rear stagnation point from moving around.
With the front stagnation point mobile, and the rear stagnation point fixed, you have an asymmetry that causes circulation. This is a rotational component to the airflow around the wing which causes air to flow over the top faster than the bottom, such that the stagnation point is at the trailing edge. This circulation causes the air to be deflected downward, and causes lift.
In summary, wings generate lift by deflecting air downwards, which is equivalent to saying they generate a pressure difference between top and bottom, which is equivalent to saying they generate a speed difference between top and bottom. Wings accomplish this by having a sharp trailing edge, which causes circulation that deflects the air. Wings are shaped the way they are not because the asymmetry is necessary to generate lift, but merely because it's more efficient that way, by changing where the front stagnation point occurs, or by generating less turbulence in the air.
Lift, on the other hand, requires forward motion through the fluid and produces a downward force. A floating boat will rise even higher in the water as it begins to move because its hull produces lift. An airplane is not buoyant (well, technically it is, but not for any practical purpose), so it requires forward motion in order to stay airborne.
Lift is anything but free energy. Remove the airplane's energy source and it won't be in the air for long!
So the plane doesn't have enough power to counter-act its weight. There's something about the air that's actually supporting the plane. And no one knows what it is yet.
Forget the plane, let's look at something a bit simpler that's basically the same principle.
I have a driveway that's maybe 10 feet high from end to end. At max thrust, my legs can (or used to be able to) lift around 350lbs straight up. But yet I can push a 500lb+ machine up the driveway without much trouble. Does that mean I'm producing free energy?
Hint: google "wedge"
Owning a Cessna means you have to pay for a tiedown or a hangar at an airport. With this, you can hangar it in your garage. The added expense doesn't really make sense, but it certainly makes it more convenient.
The same with premium laptops, people like myself don't mind paying an extra $1000 for a MacBook knowing its an easier, smoother experience. Likewise, a wealthy pilot might prefer this to a Cessna because it makes things simpler.
I am buying stock.
There's less variety of engines than airplanes, so the engines are produced in greater volume, but even after years of mass production their prices are still high - a new 150-200 HP engine will set you back more than a nice luxury sedan.
Vertical take off and landing should be priority number one.
1: http://www.terrafugia.com/images/photogallery/March10_2012%2...
2: http://www.terrafugia.com/images/photogallery/LeavingGarageW...
No, it's not. You can buy lower-end models of Cessna and Cirrus at similar price... and Cessna Skycatcher costs only half of that ($149,900).
A used airplane is probably decades old. It's probably selling for a similar price to what it originally went for when it was new. Maintenance costs are high, but they were high when the thing was new, so that's not particularly remarkable.
I'd wager that the majority of light aircraft flying in the US today would qualify for "antique" license plates if they were cars. It's a substantially different market, where the equipment lasts longer and buying used is much more common.
If you just want an airplane, you can get a lot more airplane for $279k. You can get a nice new Cessna 162 for $150k.
I'm not sure what the benefit of the concept is. You're only ever going to drive it from your house to the airport and back. A routine traffic accident will be very expensive and will attract unwanted attention and paperwork from the FAA and NTSB.
If you buy a regular plane you can leave it at the airport for very reasonable tie down or hangar fees, and know it's going to be safe and well cared for.
edit: Anticipating an objection, one could posit this is good for commuters. There is actually a segment of the general aviation population that fly themselves to a job in another city and back every day. You could use a roadable aircraft to drive to the office.
I'd say it's cheaper and better to buy a car and pay to keep it parked at the airport.
Still looking for any practical advantage. If anyone thinks of one I'd love to hear it.
Just thought of another possible objection: "But you don't have to get out, you can just drive into the airport and take off"... no, you can't. You're getting out of that plane to do your preflight checks or you have a death wish.
I doubt this is the final answer, but it's a good start.