I'm skeptical. This is the same company that "spent 40 years developing a Skycar that hovers 15 feet off the ground", according to a fraud complaint filed by the SEC.
It is this commenter's position, however, that flying cars will not--forgive me--take off until they are flown by computers. Before anyone suggests that isn't on the horizon, aircraft manufacturers are toying with designing totally automated cargo planes right now. Passenger planes, too, but there are some psychological challenges to be overcome there.
They have to do the tests with a tether attached to the vehicle, just in case something goes wrong. It looked slack in the video, so I don't think that's what's holding the saucer up.
What I like about the video is that they have friggin' crop circles on the ground where it's launched.
On second thought, this little vehicle could make my life easier right now. While others are stuck in traffic on one of the bridges, I can flit about on Tampa Bay in my little saucer. Excellent.
Of course, the thing is, this technology simply can't produce anything that flies higher, since it depends on a cushion of air between it and the ground. So, if these became the primary mode of transportation, they'd still only be able to travel over unobstructed ground (ie, not over trees, buildings, etc) and they wouldn't be able to travel above each other -- not much of an advantage over cars. Considering that they've got to use far more energy than cars, I don't see what the benefit would be.
I'm not sure that that thing would fly over water. It's getting lift from air bouncing back up at it from the ground; some of the air would probably dissolve into the water.
What, you mean the automated planes will drink more than the current pilots? I find that hard to believe.
Actually, the proper chastisement would be to say that the pilots' unions will never allow this. At least, not without them being paid to be passengers.
I'm not sure that that thing would fly over water. It's getting lift from air bouncing back up at it from the ground; some of the air would probably dissolve into the water.
That music has a definite Japanese animation flair. Huh.
Say, what happens to a person who stands under the saucer?
carrick,
Which is why I think the only way we ever get to ubiquitous flying cars is when they are totally automated and networked. Last thing I need is to have to pull flying cars out of my pool every evening.
Actually, the proper chastisement would be to say that the pilots' unions will never allow this. At least, not without them being paid to be passengers.
In the future, the flight deck will have two seats, one for the pilot and one for a dog. The pilot's job will be to feed the dog. The dog's job will be to bite the pilot if he/she tries to touch the controls.
It would have been a little more credible without that huge crane in the area. When they can show us a field test without needing a crane in the area, then I'll start to believe this isn't a vaporware idea.
Yes, SIV, air dissoves in water to some extent, a fact for which most marine life is thankful. Given the increased pressure that would be experienced beneath one of these things, it would dissolve even more so. Though, an even bigger problem would be that a lot of the air molecules' energy would be consumed by the water surface deforming, so the air that was coming back up wouldn't be able to provide the same amount of lift as over solid ground.
Local legislature has just enacted "Boating While Intoxicated" laws. I wonder if this is on their radar. I mean, are we gonna wait until some A-hole slams into a bus of chillins?
Considering that they've got to use far more energy than cars, I don't see what the benefit would be.
Their website doesn't give the efficiency of the Skycar in the video, but the blinged-out M400 gets 20 mpg of ethanol. A lot better than I would've guessed.
I'm not sure that that thing would fly over water. It's getting lift from air bouncing back up at it from the ground; some of the air would probably dissolve into the water
The amount of air which could dissolve in the water would have no effect on the flight characteristics(at first I was trying to find the joke hidden in there). I'm no rocket scientist but this thing should be more stable and predictable over flat water than an irregular ground surface.
It would have been a little more credible without that huge crane in the area. When they can show us a field test without needing a crane in the area, then I'll start to believe this isn't a vaporware idea.
I thought I heard somewhere that FAA mandates tethering in order to allow them to test fly these things. I may be wrong
word to the wise, I would take anything from Moller's website with a mine of salt. As I linked to above, he had to pay $50,000 in fines to the SEC over his fraudulent marketing of the M400.
Keep in mind, the M400 has reached a maximum of 15 feet altitude in purely vertical tests; I'm not sure what the fuel efficiency claim is based on, since that would require long-distance horizontal travel to substantiate.
Also, in my travels on this subject, I found this video of a Chinook helicopter self-destructing due to ground resonance.
Pah. I want the real deal, not some cheap overpowered and undercapable hovercraft. And while I'm on the subject, where's my lunar vacation home? My fellow geeks and nerds are failing me. I want the future I was promised.
I'm no rocket scientist but this thing should be more stable and predictable over flat water than an irregular ground surface.
That water surface is not going to remain flat when you have 6 big-ass fans blowing down on it. The energy expended deforming the water surface is energy not available to hold the flying car up.
"ground effects"--effects of the existence of the ground on the aerodynamics of a hovercraft, airplane, or car. Provides more lift.
This is why planes can take off slightly below the rated stall speed for an aircraft. Problem is, as soon as they get more than about a wing's length off the ground, they'll be out of ground effect, will be below the stall speed, and crash. (This is why pilots make sure they're above certain speeds when taking off.) Here, since the air is being blown downwards, I expect the vertical distance for ground effects to be much larger.
(Ground effects also responsible for "ballooning" while landing if you're not careful.)
Most ground effects taper off at at a height of 2 to 3 times the wingspan. So, while it probably benefits from ground effects, it appears not to require them. In low-power, low altitude conditions, one might fly past the edge of an embankment and crash due to sudden loss of ground effects. It would probably fly over water, but not as well as a true hovercraft or helicopter.
The visibility below the pilot/driver doesn't seem adequate either. Looks like it could easily experience a hard landing on an uneven surface.
could someone please explain something to me? The whole flying over water discussion sounds like you all think this thing relies on a cushion of air between the vehicle and the ground. I'm not an engineer but my first reaction is that it relies solely on constant thrust which would have nothing to do with air pushing back up after bouncing off the ground. Does a helicopter need air to bounce off the ground to push it up? No. In the video this thing flies quite high, I'd say 50 feet; It could not fly that high if it needed a stable cushion of air between itself and the ground.
You know, you could increase the ground effects by putting a skirt around the based of the saucer. Then you could increase the size and power of the saucer big enough to haul cars and people across the English channel . . .
Scooby and crimethink: you are completely wrong regarding the effects of water regarding hovercraft. You can either accept that or research it yourself.
You're not saying that significant variations in pressure on the water surface aren't going to deform it, are you?
Given the example saucer (hovercraft) above, it is small, lightweight, and does not require "much" lift to get off the ground. The airflow produced by the engines might deflect the water surface directly under the saucer by an inch or two, but I suspect it is even less than that.
I don't know how much I think this craft relies on back pressure to overcome gravity so much as the thrust it's generating right at its fans. Whatever the mechanism of lift - pressure differential due to a Bernoulli effect or momentum transfer, whatever - I don't think it's because the airflow is hitting the ground. A column of moving air isn't some stiff, load-bearing thing that communicates that kind of reaction force back along its direction of travel. It's a fluid.
When a spacecraft launches the relevant balance of forces occurs in the engine bell, not on the ground. If I think of ground effects that aircraft deal with I know it's not ground induced pressure. I think it refers to a boundary layer wherein the velocity of the air is affected by the presence of the ground and the effects of viscosity. But the pressure within a boundary layer is the same as the pressure outside of a boundary layer. That is, a basic assumption of boundary layer theory is that the pressure outside of it is impressed into it.
I'd need to know more than I do about this aircraft to really go to the mat on any of this, but I'm thinking the mechanism of flight is not a back pressure due to the proximity of the ground.
I'd like for this to be a real deal just as much as anyone, but Moller's gonna have to come up with some newer video than the 1970s vintage stuff here.
If he can't demonstrate it's use in a modern video without the tether, how can he expect anyone to want to buy the thing? If he wants to SELL it to people for use without the tether, he needs to show it being used without the tether.
The FAA (or whoever) might have testing regulations while it's being developed, but at some point you have to shed the training wheels. Do you get my point here?
I've been a hopeful fan of the M-400 for several years now, but stunts like this are making me lose faith in the whole Moller enterprise.
Excuse my lousy memory, but didn't I see this *exact* 'flying saucer' many years ago in either Popular Science or Popular Mechanics? And I don't mean similar, I mean the same saucer, right down to the paint job...
I remember running across the following in Physical Review Letters when I was in grad school. Clearly it explains how "flying saucers" work and the key to making flying cars work (spin it real fast in the CORRECT direction). Anyone know of any follow up research that has debunked this? I havent looked in about 10 years.
The link is from some weird website, but most of the links I found want me to buy the article.
If its primary lift is due to thrust from the fans, how come it can't travel higher than 3 meters? If the thrust is sufficient to lift it to that height, how come it isn't sufficient to lift it any higher? True, helicopters and other thrust-powered air vehicles also have altitude limits, but that's because of the decreased density of air at very high altitudes. That shouldn't be a problem at 10 feet.
I don't know why it doesn't fly higher than three meters. Maybe it
s capable but not authorized? Maybe something that stays near the ground, such as a hovercraft, is developed in a different regulatory environment than something that flies at 3000 feet which would invoke FAA regulation.
Still, propulsion on aircraft do produce fast-moving air but the thrust generation that caused it to be fast-moving has already occured by the time it leaves the aircraft.
And if you look at the vehicles that really do ride on a cushion of back pressure you'll see that they make that back pressure by compressing air into a confined volume, such as inside the skirting on a hovercraft. If you take that skirting off you don't get the pressure differential that keeps it (barely) off the ground. That's because fluid is just too easily displaced to transmit a force from the ground to three meters above the ground. It's not solid. It's moving. I believe that its motion is due to the force that is reacting to the lift-generating force (see Newton's law of action and reaction).
Ground effect doesn't *require* a skirt, that just makes it more efficient. Both fixed wing aircraft and helicopters will experience ground effect lift when they're close enough to the ground. Roughly, at an altitude not much more than the size of the aircraft.
Hovercraft won't hover without the skirt because they're powered based on the assumption that there IS a skirt, and without it don't have nearly enough engine power to stay in the air. If they had powerful enough engines, they wouldn't need it, just bigger gas tanks. ;)
And I still say I've seen this particular "flying saucer" before somewhere, and not recently, either.
In my estimation, the thrust from the fans is nearly equal to the weight of the saucer. If it was equal or greater, ground effect would not matter.
What is happening is that there is a slight high pressure area produced by the downward airflow under the saucer, building up due to being "trapped" by proximity to the ground (water, whatever). This exerts a small additional force on the bottom of the saucer, allowing it to climb, until it reaches a height where the pressure is reduced to essentially zero because the distance to the ground is too great to "trap" the airflow to any extent.
At that point it cannot climb further. That is what limits its altitude. That height will vary with the weight of the pilot, temperature, etc. With a child flying it you might even be able to fly away into the sky, but most aircraft have a lot more reserve lifting capacity than this thing does. It is basically a high-powered hovercraft.
The Avrocar used 3(?) small jet engines to rotate a huge fan-wheel, not via a turbo-shaft arrangement, but by firing the jet blast against the perimeter of the fan-wheel itself. This was the first attempt that I know of to use this method of generating lift, and I don't think there was enough development time and money available to make a flying vehicle.
So I think that this saucer has a higher achieved thrust-weight ratio than the Avrocar had, but the Avro probably had the potential to become a flying vehicle, even a high-performance one, with millions more dollars and years more time.
The guy that built this thing has been living on promotion for decades. It uses eight - two stroke engines each powering a fan. Since two stroke engines on ultralights fail regularly after a few hundred hours, and this thing looks like it has eight of them, I give any new owners of the things about a week to live.
What is trapping air into a column that's three meters off the ground? What keeps the air in that volume at a pressure differential from the surrounding atmosphere? If there's a stagnant zone somewhere in the impinging airflow where the pressure might rise a little it sure isn't three meters high.
And if there's a ground effect felt by a helicopter, with a far broader flow field, is it enough just to be felt or is it great enough to actually lift the aircraft? Those two things are vastly different. The notion of ground effect being the primary source of lift for this craft requires the ground not to just have an effect but to do all the work.
Not to be too parsimonious, but I'm much more comfortable with the idea that the craft hovers by generated thrust or lift, not back pressure from the ground in some bizarre pressure zone that's doesn't vary measurably for at least three meters from the ground. Seems like that would be something like the Saturn V.
Of course, the thing is, this technology simply can't produce anything that flies higher, since it depends on a cushion of air between it and the ground. So, if these became the primary mode of transportation, they'd still only be able to travel over unobstructed ground (ie, not over trees, buildings, etc) and they wouldn't be able to travel above each other -- not much of an advantage over cars. Considering that they've got to use far more energy than cars, I don't see what the benefit would be.
Ummm.... you don't have to stay stuck on the highway when there's a traffic jam? That might be a big advantage.
People aren't necessarily going to like you cutting across their front yards, though.
You will always have a cushion of pressurized air behind the thrust due to Newton's third law. The difference between a hovercraft and a helicopter is that in a helicopter the lift is provided by the pressure difference between the blades' bottoms and tops while the hovercraft also makes significant use of the bottom of its body. This craft does look to be making some use of its body, since I assume if it wasn't they'd cut out some of the frame in between the fans to reduce the weight. Skirting will help both mechanisms - ducted fans, for example, can be more efficient than unducted propellers by keeping the pressure up at the ends of the blades by preventing the air from flowing out sideways (they also have some other benefits and drawbacks). It's particularly useful for craft where the ground effect is significant, since you can cut off almost all the loss of pressure in the column of air below you due to horizontal movement of air out of the column if you can keep the skirt close to the ground and it matters a lot when the craft uses its body for lift since the edges have the same issues as the ends of the propeller blades.
When flying over water, it should displace some water, but not that much, since it should only need to offset its own weight and water is pretty dense stuff. Something like this won't have to displace any more water than a small boat. I think if it were heavy and narrow enough, the weight of the craft and the compressed air necessary to support it underneath the level of the water could be greater than the water it is displacing and it could sink. The normal force from the water will be the same as the pressure at the depth of the displacement * the area at the bottom of the displacement, so if the craft doesn't float at a height greater than the depth at which the pressure is equal to that at the ground underneath it when it is operating over land, chances are good it may sink.
Of course, this is coming from someone who learned fluid mechanics dealing with pipes rather than planes, so I may be wrong.
Paul Moller has been looking for people to fund his projects for decades now. The "flying car" is nothing more than the stuff of cartoons. While I believe it is worthwhile to see what you can do, the commercial application of such a venture is a pipe dream, esppecially for the common folk. Any time you are not in contact with the ground you will be fighting the wind and inertia. Go flying in a private plane, pay the $50-$75 and find out what flying is about. Think about how wide the runway is just to keep something that really flies in a straight line. At one time I thought this would be cool, but I am convinced that Paul Moller is just looking for somebody to pay for his fun.
The article says that it's lifted by a cushion of air, and that it's designed for a maximum alt. of 3 m. I'm not an aeronautics expert, just a physics major, but I'm skeptical because a vehicle that provides sufficient thrust to lift its own weight should be able to continue lifting its own weight up to much higher altitudes (ie, until the density of the air significantly decreases). So I'm figuring there must be something lifting it besides the thrust of the fans.
Plus, apparently the guy who's promoting this is a shameless liar, which isn't helping this story's credibility.
I would have been much more impressed if I saw it actually go somewhere.
It really needs a flight-computer; it looks like it's inherently unstable -- as forgiving to fly as a (conventional) helicoper. As one poster commented: one wind gust away from bad press.
This should not have any more trouble over water than a hovercraft.
Helicopters stay in the air by suction -- yep you heard me right ;-) Suction: because of the moving blades' airfoil-shape, the tops are under lower pressure than the bottoms. This results a vertical force to offset gravity: lift!
I'm about to commit, as Patton the Elder put it "the greatest heresy" by speaking on experimental aviation from the standpoint of an experimental test pilot, who has built several of his own aircraft.
Ground effect is relative to wing loading, wing area, span and aircraft weight. A big plane has a lot more ground effect than a Cessna.
The Skycar has a very high loading, but a low area and small wingspan. Thus, the ground effect component of lift is negligible above about 3 feet. In addition, it has no skirt to collimate the pressure.
The crane is to keep the prototype from being destroyed while the pilot learns how to fly it. They used to the the same thing with the first helicopters, except in that case they were tethered to the ground, so that they could only lift 3 - 4 feet. The Skycar's center of gravity is close to or even above the center of lift -- and there aren't any aircraft even remotely like it to learn on then transition from. It is significantly less stable than a helicopter. I makes me think of an elephant on a beachball -- not that it is DIFFICULT to fly, but that it is DIFFERENT to fly, and the pilot has to keep the pivot point where he wants it to avoid embarrassment. Anyone who can surf, ride a unicycle or hop on a pogo stick knows what I'm talking about.
This is older video, it's been around a while. It's intended as proof-of-concept, to get investors. It's not a sales commercial for the local dealership. "No bucks, no Buck Rogers" -- it takes a lot of money to bring a new technology to market. To have gotten so far on so little is nothing short of a miracle. However, as Curtiss and Sikorsky found out, the big money is spent by the initial developer, then everyone else looks at it and says "Oh, yeah, I see how he did it!" -- thus saving 5 or 10 years of R&D. Moller is trying to avoid that same fate by being cagey about his technology, at least long enough to see his work pay off.
The AVRO Disc was more closely related to a helicopter than to the Skycar. It was a big, ducted fan. The Skycar is several smaller fans, and that's about where the resemblance ends. They are as closely related as a Chevy and a motorcycle.
Now, for the $64,000 question: "Would I fly the thing?"
PROBABLY NOT. I did fly a jet belt once (8 times, actually, but the same experiment series, and Bill Suitor has nothing to fear from me), and it gave me the clanks -- any failure at altitude meant getting my name in the paper (but not being there to read it).
A helicopter can lose power and float down to a safe, gentle landing -- this is part of training to fly rotors, and is really kind of fun. The jet belt and Skycar fall out of the sky if you have engine problems. That can wreck your whole day.
Oh, BTW, ground effect DOES NOT make a "dent in the water." Liquids are non-compressable. You don't lose any ground effect transitioning over water or land -- you don't even notice the transition.
Also, no, helicopters DO NOT stay in the air by suction. They stay in the air through pressure on the bottom of the blades.
BTW, speaking of jet belts, there are guys experimenting with HOMEBUILT jet belts.
It's a bird! It's a plane! It's a viable flying car!: