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Fabulous Flying Machine Progress 152

HobbySpacer writes "A SoloTrek video shows a recent tethered hover test of the one person VTOL vehicle.The company has DARPA and NASA support and has carried out a number of sucessful wind tunnel and power tests. Meanwhile, the CarterCopter RotorWing demonstrator may soon show for the first time that a vehicle with a rotor can safely achieve very high airspeeds (e.g.400-500 mph) where the tip speed is actually slower than the vehicle speed. This has been a great project to follow since they are so open and honest about the various problems and fixes during the development. Just wish Moller was as transparent about the Skycar. At least a video and some images were recently posted showing the nose of the craft lifting off under its own power."
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Fabulous Flying Machine Progress

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  • by Anonymous Coward
    The statement that the rotor tip is moving slower that the body is incorrect, it should be obvious that this is a physical impossibility. The assending blade is moving forward 100MPH RELATIVE TO THE VEHICLE which means 600MPH. The retreating blade is another story. The point of the article is to prevent the assending blade tip from reaching speeds past the speed of sound. So there.
  • by Anonymous Coward
    If you still have your rotors attached, you can do something to save your ass:

    Dive. The increased speed from your dive increases your rotor speed significantly.. After the rotor speed is sufficient, you can get out of the dive.

    You just have to pull back on the stick before you hit ground... This is a real one-shot deal unfortunately because once you pull back, you lose your rotor speed and start falling again. Try to be close to ground ;)
  • by Anonymous Coward
    The whole concept of a powered-list/vectored-thrust flying machine is so incredibly dangerous. Just look at the history of R&D on the Brittish Harrier jump jet and how it took so many years to get enough kinks ironed out of the engineering and technology just to get it to a state where only the very best of the best of pilots could just barely keep it under control in thrust-lift mode. Look as the abysmally poor track record of the V22 Osprey too, what a flying coffin that machine is!!!

    The CarterCopter, on the other hand, relies on much more proven controllable aircraft principles, and has finally been test flown up to 139 knots airspeed and handled about the same as more conventional gyrocopters once they figured out the basic operational parameters of the hardware combination it consists of. I've personally witnessed the CarterCopter four times so far in the past two years and it's coming out of its "infancy" state of test flights, and is now well into the "toddler" phase. Pretty soon it will be in the "full child" and then "adolescent" phase where then it will be pushed to the break-the-mu-barrier tests. The CarterCopter folks are at Oshkosh right now and have announced that probably Oshkosh 2003 it will be ready to make full-blown demonstation flights of its technological prowess. That's only a paltry 24 more months away folks, that's a mere blink of the eye in aviation development timeframe (as opposed to internet/computer timeframe where 24 months is an eternity :-)
  • by Anonymous Coward
    Umm, what about all that DRAG from the rotor system? Sure, they've "solved" retreating blade stall by flying the thing on the wing at altitude, but since the rotor system is still turning, the energy to turn the rotors is pure drag

    Yep, the rotor system will still be windmilling and creating some drag, but since it's completely unloaded (producing zero component of lift) and the RPM of the rotor can be precisely controlled and limited, the amount of rotor drag as well as other total aircraft drag under such conditions has been calculated to be theoretically able to be just overcome by the amount of thrust available from the unique pusher propellor and big Chevy aluminum V-8 engine. Everything in any aircraft is a system of trade-offs and balances anyway.... the Carter folks think they have just found the magic envelope of lift, drag, thrust and weight to get over the mu barrier. It won't get over it by very much, but I think it will get there and cross it by a margin large enough to just be barely measureable and confirmable. To be able to dramatically break that barrier, they'll need to use a very high thrust turbofan.
  • Actualy you need *MORE* thurst at lot altitudes, because the air is thicker. Why do you think airliners fly in the space between 27,000 ft and 41,000 ft (Well Flight level 270 and 410 actualy)
  • The CarterCopter does not spin because it is not a helecopter, it is a gyro. The main roter is not connected to anything and is autorotating. The engine is driving a push prop.
  • True but this is more than made up for by the fact that the aircraft has more drag at low altitude. Check out any turbocharged or jet aircraft performence chart.
  • They are still smoking something, if you have an engine that can deliver 150 hp sustained and burn 1.5 gph I would be very suprised. The Rotax 912 engine burns about 4.2 gph and only delivers about
    70 hp (80 is takeoff power but by the time you have climbed a few thousand feet you are down in the 60-70 hp range). So even if it used *HALF* of what the Rotax (Which is a 4 cylander) it would still be burning 2.1 gph/engine times 8. And I don't think you can get that kind of speed out of that kind of thurst.

    --Zach Kessin
    Private Pilot
  • IF the engine dies you glide. Same as in an airplane. You do practice this a million times before you go solo.
  • The class (Powered Lift) has been in the FAR's for a while. The Moller one will nevery fly but Bell and Boeing are working on something like a Civilian version of the V44 Osrprey that will be a powered lift craft. It will be smaller then the one that they are making for the marines. And when Bell and Boing announce they are building an aircraft unlike Moller I actualy belive them.
  • This applies to the US only, other countries may vary.

    First of all to fly eather of these things you will need to have a pilot's licence, which requires a fair investment in time and money to get.(At *LEAST* 40 hrs of flight pass a test etc)
    They Gyrocopter can be treated as an Airplane by ATC except for takeoff and landing. In addition if it is as high powered as they are saying then your insurance company is going to make sure you meet a set of training requirments far above what the FAA will want to see.

    Also they will not be as cheap as people are claiming the cleapest 4 place certified aircraft these days costs about $145,000 new. (The Cessna 172)
  • No feathering is what you do to a twin when an engine fails. It takes the prop and makes sure that it does not spin and create a lot of drag. From what I know about autorotating that is more or less right for a helicopter. Note that this does not apply to a gyrocopter. One of these days I want to learn to fly a helicopter, but at $200/hr and up it won't be soon.
  • The specs say it will cruse at 15mpg and 350 mph. That means that it will be burning 24 gallons per hour. But it apeears to have 4 engines, which means that it will be using 6 gph per engine. I would love to know where they plan to find a Jet Engine that uses 6gph and still can turn out the type of thurst that they will need to go 350 mph, even at 25,000 ft.
  • Well sort of, they use the engine to spin up the roter, but once you are airborn the roter just spins due to the air passing threw it. Helecoptors can do this as well, its what you do if the engine dies. Gyrocoptors can be setup to take of and land with basicly no runway, but they can't hover or take of verticaly. So they need a clear space to climb over obsticals or whatever.

    I would get a gyrocoptor rating if I could find flight school around here that gave them, but for now I will just stick to my little airplane.
  • You are comparing an efficiency (2/3 hp/lb) that was actually measured in the real world, to one of Moller's outrageous figures pulled out his ass.

    Moller is a con artist of high caliber. Every time his company is running out of money, he announces some new breakthrough, but doesn't show it to anybody. I'll believe in his flying machine when it actually flies, and not a day earlier.

    Actually, I don't believe that any of these personal flying machines will achieve the goal of making flying accessible to non-pilots. There are just too many factors involved in the judgement involved in being a pilot to believe they could ever be automated. And car drivers are far more prone to "get-home-itis", but rarely die from it. In a plane, you just can't pull over until the thunderstorm passes - if you're in it, you'd better have an up to date will, because it's too late to do anything except hold on and hope you don't die.

  • Wankels were used for early high performance Mazda automobiles.
    Yeah, and they ate gas and produced smog at a prodigious rate. Moller is claiming much higher power at much lower fuel flow than any engine known in the world. Has any independant lab tested Moller's miracle engine? I don't think so.

    Moller has given demonstrations to everyone.

    You mean like that so-called "hover test" which actually shows the thing dangling on a wire? Looks like those "yogic flying" demos, or some of the worst of the UFO film, except Moller has less credibility than either of those two groups.

    Moller's been working for over 20 years on this stuff. Show me one "aircar" that he's produced that can hover under its own power, and fly with a pilot on board. So far, all he's done is make a lot of claims, shown a couple of rigged demos, and redesigned his fuselage a few times to make it look cooler but less aerodynamic.

  • Consider if you will, a future where...

    all aircraft (including small personal craft) have a differential GPS receiver on board that computes position and velocity vectors with great precision;

    said aircraft wirelessly network with all other aircraft within, say, a 20 km radius, transmitting their position and velocity vectors;

    each aircraft runs an algorithm that would predict any collision or near-collision with another aircraft (or its turbulent wake) well in advance, and automatically makes minor course corrections to prevent them. (Not a big deal, because these personal aircraft won't be actively "piloted" anyway -- the "driver" will simply enter the desired destionation then sit back.)

    and each aircraft has a fully redundant system (two GPS receivers, two transmitters, two CPUs) to ensure reliability

    Many, many advantages to this kind of system:

    no more mid-air collisions due to human error

    aircraft can be much more densely packed in the sky -- current spacing regulations have an enormous factor of safety built in, because frequent human error requires it

    no more spending $billions to upgrade the ATC system -- the legacy ATC system can be done away with altogether when the last aircraft is retrofitted

    VTOL craft can safely land anywhere (parking lots, reinforced roofs)

  • "Beside the obvious concerns regarding to safety of the commute, I wonder how you could make it cooler. Can't seem to lower it or add alloy wheels to it. I guess you could make the flight stick smaller and put some UV light underneath it, but it's still not the same thing now is it... "

    I've seen alot of nice spoilers on slammed Honda Civics. Couldn't you put one on the Moller - wait - never mind...

  • These things scare me. They're going to make it impossible to just get away. I try to go hiking in the mountains for a week, away from motors and noise. I succeed because there are very few vehicles that can get to the places that I can walk to. These would put an end to solitude - hike as far as you like, you're still within reach of a yuppie punk and his flying machine.

    They'd better revoke "indecent exposure" laws when these things come out!

  • must be a quantum effect. that whole half of the spinning rotor must go to another dimension where it is going backwards. thus the rotor doesn't move.
    hmmmm infinite MPG. no! it's a fuel PRODUCER!
  • If you're heavily into aviation, then AVWeb [] ( is a good site to visit. All sorts of good stuff there.

  • They also need to feather the rotors at precisely the right moment, to generate lift that will keep them from smoking into the ground.

    If you fail to feather soon enough, you impact the ground... very hard.

    If you feather too soon, you actually gain altitude, then lose the ability to autorotate, and plummet to the ground... very hard.

    If you do it just right, you generate just enough lift to achieve no velocity just at the moment the helicopter touches down. Or, more likely, almost no velocity, so that you impact the ground gently.

    (I think it's "feathering." Something like that.)

  • The price is in there... taken from the FAQ page:

    4.3. How much will M400 cost?
    In limited production (500 units per year) the M400 Skycar will sell for a price comparable to that of a four-passenger high performance helicopter or airplane, approximately $500,000. As the volume of production increases substantially, its price can approach that of a quality automobile ($60,000-$80,000).

  • by jonbrewer ( 11894 ) on Thursday July 26, 2001 @09:05AM (#2191813) Homepage
    From the SkyCar technology page:

    "Moller rotary engines were developed from technology obtained from Outboard Marine Corporation (OMC) and are of the Wankel-Type. During each rotation of the rotor a four-stroke spark ignition combustion process occurs in each of the three pockets of a triangular rotor. After one full rotation of the rotor the engine has completed the four-stroke process three times. They therefore provide a high power-to-weight ratio at a reasonable cost and are very small for their power output. The 150 HP model used in the M400 can be easily carried by one person. Eight Rotapower engines are used in the production model volantor."

    They're not using a jet engine, they're using rotary engines known to be incredibly efficient.

    Check out this site for some good reading on the technology: []

  • The CarterCopter is using a turbocharged auto engine. Many people would like to see auto engine technology into aircraft, but so far this has never gotten past the experimental stage. Currently aicraft engines are remarkably crude designs (somewhat heavy, inefficient, low power), but exceedingly reliable. Engine failures are rare events; which is good since engine failures are almost always minor disasters.

    There was one serious attempt by Porsche [] that was a dismal failure. It is doubtful that this powerplant will be viewed as reliable enough by the FAA for aviation use anytime soon.

  • by Sloppy ( 14984 ) on Thursday July 26, 2001 @09:03AM (#2191815) Homepage Journal
    While these machines are pretty neat, they look rather spartan. I mean, where is the cellphone, the makeup mirror, cupholders, entertainment center and web terminal? God forbid the driver should have to devote the entirety of their travel time, to just piloting the craft.
  • flight patters

    "I tailed up, flogged out, he dicky-birded, and the nabber tickled on the tocker-bang."

    My apologies to Monty Python for that terrible, terrible paraphrase.

  • Don't forget the kids who can jump over one of these suckers. These flying cars will add a wonderful new set of Jackass stunts.

  • They promised us jetpacks! I want my jetpack! Where the hell is my jetpack?!
  • The correct link is: here []
  • Reminds me of the Golgafrinchans, after they've started colonizing earth, when they decide to invent the wheel.

    "But it won't work - it's not round!"

    "Bah - that's minor - the important questions are what color should it be? How big? Boy, you really don't know anything about marketing, do you?"
  • yeah, but shorter runways, like a hundred feet i think. and engine failure just means you have to land NOW, rather than crash.
  • Yeah but its pretty easy to program in a few more "sky lanes" for rush hour

    Trust me, it's not. Airspace noise restrictions are a major problem today: if you get hundreds of low-flying planes every day over your house you watch property values tank. People will fight any such action tooth and nail: I've seen it for small airports that want to allow a few more corporate jets/week in, much less this level of traffic.

    Add to that the complication of existing routes around major cities. Anywhere you'd want to avoid traffic is probably class B, or at least class C airspace. There are control towers that move all traffic around these areas for a 30-mile radius at the minimum. It's just not going to be as easy as people seem to think.


  • its what you do if the engine dies

    And what I hear from people who've done it is that it is, marginally, preferable to boring a hole in the ground. Apparently the chopper spins one way and the rotors another. At the same speed. Barf-o-matic.

  • Yeah, but helicopters glide strait down while rotating. I've seen them do it.
  • Something like this is fine if you want to have a little fun on the weekend, and you don't really have a need to be anywhere.

    But if the weather turns even a little nasty, you have to stay on the ground. And I really wouldn't use one of these too far from my home airport. Defintely no cross country.

    But if your budget is really low, and you must get up in the air, it's not a bad way to go. There are other types of ultralights as well, all the way from hangliders with engines, to almost-planes.
  • Have you ever seen a maple seed? When you throw it up in the air, it will fall gently to the ground, while generating lift from its rotating "wing".

    Helicopters don't fall quite as gently when the power is cut, but it's entirely possible for the occupants of a helicopter to survive an autorotation when properly piloted.

    Don't get me wrong, helicopters scare me, but losing power in a heli is not one of those things that keeps me away from those funny planes with the propeller on top.

    Try this: Grab x-plane or FS2000, and start up a heli simulation. Take off. Are you still with me? Taking off is harder than it looks, isn't it? Pretend you're on a cross country flight, and you need to take your hand off the cyclic, and get your sectional chart out of your bag. Notice what the helicopter does when you take your hand off the cyclic. Can you recover?

    Come back and tell me helicopters are perfectly safe.
  • You are deeply ignorant about how helicopters behave. Taking your hand off the cyclic is fundmentally different from taking your hand off the steering wheel. Driving isn't the same as flying, and flying a chopper is not the same as flying as fixed wing plane.

    No, nothing is completely safe, and for certain applications the risk of flying in a 'copter is outweighed by the benefits you get. But for day-to-day commuting, the inherent risks in flying a rotorcraft aren't worth it.

    Why don't you take a few helicopter lessons and then come back and read what you wrote? At the very least, try doing what I outlined.
  • After all, it would probably be necessary to delineate "sky lanes" for traffick, since you can't just have everybody up there drivin' around free.

    Personally I subscribe to the "Big Sky" theory of air traffic control. I mean look at it - there's so much sky up there, what're the odds that two planes would be in the same place at the same time?
  • dosent sound so bad to me. Kill off the lazy and the stupid that way, thus insuring the success of generations to come, by reducing headcount and "chlorinating the gene pool" as it were.

    Think again - this isn't some clapped-out 1978 Buick beater we're talking about here. The lazy and stupid will not be driving something that cost half a million bucks.

  • The centrifugal force from 55-pounds of depleted uranium in each blade tip keeps the rotor rigid and stable at the reduced rotor rpm and high forward speeds.

    Uranium? That's what they use in Nookyooler reactors, and those are EVIL and will DESTROY THE WORLD! The CarterCopter must be STOPPED!

  • I really like the look of the Moller SKycar. It looks like the Mach 5, but with jet engines instead of wheels.
  • by WinDoze ( 52234 ) on Thursday July 26, 2001 @08:46AM (#2191832)
    Whatever happened to Dean Kamen's [] mysterious Ginger [] project? Could that be some sort of flying machine? And why does Amazon lilst it under "Electronics"? Enquiring minds want to know.

  • nu /body.htm

    This inventor had the rather brilliant idea of using an electric transmission to drive the fans. It looks to me like he might actually deliver what Mosher has been promising for the last few decades.

  • You just have to pull back on the stick before you hit ground...

    Nah, you just do a "Bugs Bunny" and step out just before it hits. Worked every time.

  • Here's another page that shows how the wankel rotary engine works: []
  • For the record, they are not more fuel effecient. Its a well known shortcomming of rotary engines. My RX7 sucks gas like a school bus (especially when that second turbo kicks in :-).

  • >You should get better gas mileage when your
    >turbochargers are running.

    That is ridiculous. You obviously do not have any idea how an ECU works.

    >The rotary engine is far more efficient because
    >you never have to stop the pistons- 50% of the
    >horsepower that comes out of a standard engine
    >is wasted on reversing the direction of the

    68.9 percent of all statistics are made up.

    See: /4 3032/article.html

    "The advantages to a rotary engine are a complete balancing of masses, a compact design, and no need of a complex valvetrain. The disadvantages are unfavorable combustion chamber shapes, higher emissions, and higher fuel consumption."

    See also just about every FAQ ever written on the RX-7.

  • by DMoylan ( 65079 ) on Thursday July 26, 2001 @10:19AM (#2191838)
    Its bad enough when a bird hits a glass window but now we have some adult with a huge hunk of steel strapped to their back ramming the patio doors
  • Ginger, I believe, was a scooter with a fly wheel. Or that was the consensus guess, last I heard.
  • by selectspec ( 74651 ) on Thursday July 26, 2001 @08:50AM (#2191840)
    You've just outlined the key note about Skycar: 12 years development == no usable product. What happened? I remember seeing the skycar on TV like 12 years ago and thought, "cool this will be out in a few years." Now, I see that nothing has happened. What is the story?
  • The CarterCopter is being modeled and flight tested with X-Plane [] by Laminar Research []. It is the most advanced consumer flight simulator that uses blade element analysis [] too calculate ALL of the real physical forces acting on the aircraft! Check out the X-Plane Front Page [] for pics of the CarterCoptor test pilot taking a test flight on a new Apple [] G4 (in the hanger with the actual plane in the background).
  • You are correct that jets fy at high altitudes to save fuel, however this statement make no sense:

    No, no, it made perfect sense. The way I understand it, airspeed does not measure how fast the aircraft actually moves, but rather how much air moves across the wings. The measurement gets made by testing the air pressure coming across the wing and then compensating for the air pressure in still air at that altitude, which gets measured by another device that the air doesn't flow across. Therefore, an airplane moving at 350kts will have the same air pressure coming across its wing at sea level and 25,000 feet, and hence, the same amount of drag.
  • Wait a minute... you just told me the same thing I told you. In other words, I do understand it. =-)

    Ground speed measures how fast the airplane moves across the Earth, and airspeed measures how fast air moves across the wings. In a nosedive, the ground speed drops to zero while the airspeed rises. Of course, this tells you how fast you go, but it doesn't directly measure that. It simply measures air pressure, which gets affected by (at least) two things: the speed of the aircraft and the density of the air. At a given ground speed, your airspeed drops as you go higher, so you experience less drag. Conversely, at a given airspeed, your ground speed goes higher at higher altitudes, so you experience the same amount of drag.

    The bottom line: Since airspeed doesn't measure any particular speed, but rather pressure, at a given airspeed you will experience the same amount of drag at any altitude, because you have just as much air coming across the wings.

    Anyway, for the most part, knowing how fast you actually move at a given times doesn't work out as important as knowing whether you have enough speed to create sufficient lift, which the airspeed indicator will tell you regardless of your altitude. Naturally, as you go higher, the lesser density of the air means you need a greater groundspeed (and therefore, more thrust) to get the same airspeed, which explains why all airplanes couldn't just keep climbing until they reach outer space.

    I just noticed, however, that when you quoted me I said, "an airplane moving at 350kts", which I suppose accidentally implies ground speed, when I really meant to say "an airplane with an airspeed of 350kts", so this may have caused some confusion.
  • by FlightTest ( 90079 ) on Thursday July 26, 2001 @09:45AM (#2191846) Homepage

    A SoloTrek video shows a recent tethered hover test of the one person VTOL vehicle.The company has DARPA and NASA support and has carried out a number of sucessful wind tunnel and power tests.

    Um, and exactly what do you do when the engine dies? Oh, yeah, that's right, YOU die. The rotors are too small to have enough inertia for successful auto-rotation. DARPA and NASA support do not signify this will ever be available to the public, or even USED in the military. If anything, this is a "see where the technology goes" program, not something anyone envisions ever being viable. Did you LOOK at the video? That isn't a "teathered FLIGHT", that's hanging from a wire. No proof of ability to actually produce enough lift to fly under it's own power. No proof of any kind of controlability when not supported by the wire.

    Meanwhile, the CarterCopter RotorWing demonstrator may soon show for the first time that a vehicle with a rotor can safely achieve very high airspeeds (e.g.400-500 mph) where the tip speed is actually slower than the vehicle speed. This has been a great project to follow since they are so open and honest about the various problems and fixes during the development.

    Umm, what about all that DRAG from the rotor system? Sure, they've "solved" retreating blade stall by flying the thing on the wing at altitude, but since the rotor system is still turning, the energy to turn the rotors is pure drag. You mean Gulfstream and Bombardie and Cessna have wasted all that money making thier aircraft aerodynamic? The Gulfstream IV is only certified to 45,000. They obviously aren't going to power the "real" one with a piston engine, but even a turbine will only output a fraction of sea level power at that altitude. So far, they've achieved something like 2000 feet, and they've only crashed 3 times!

    Just wish Moller was as transparent about the Skycar. At least a video and some images were recently posted showing the nose of the craft lifting off under its own power.

    Moller. How long has this guy been promising "real soon now"? And the pics show the nose being lifted by "2 of the 4 front engines". How many engines are in the back? Probably at least 4 more. Where is all the fuel to run all these engines going to be stored? And oh, by the way, Avgas is about 6lb/gal. At his claimed speed of 350mph, and 15 miles/gallon, that works out to 23 gallons per hour. Total. For ALL the engines, not each engine. Wonder why most twins suck around 15-18 gal/hour/side and don't go anywhere near that fast? And, oh, by the way, looks like if you run it out of fuel, you die.

    Aviation is full of this kind of crap. Even Eclipse, a relatively convential design promising a 365 knot jet for under $900k is smoking crack. They claim first flight will be July 2002 with certification by the end of 2003. Not a chance. Even presuming that thier first aircraft is fully conformed and doesn't need any tweaks requireing more than extreamly minor redesign, you can't certify a twin jet in 18 months. There's too much flying, too much testing, too much red tape to cut through.

    Nothing to see here, move along.

  • Courtesy of Apple [] - I chucked the video on my idisk. It's 1.6 meg Quicktime. Kick Apple's server in the nuts [] and see how it holds up under the slashdotting, I've always been curious. :)

  • There is this invention, perhaps you have heard about it. It's called the parachute!

    BTW ultralights probably fit into this same exact category as these machines, and again, rocket fired parachutes can save your but even from very low altitude.

    "Science is about ego as much as it is about discovery and truth"

  • I'm sorry to say this, BUT this "tethered test" looked more like a yo-yo dangling on the end of a string. If the bloody thing had listed OFF the ground under it's own power I might be more impressed. For all I know (and what they say isn't necessarily what happened mind you) the damn thing was lifted into the air buy that large WHITE crane in the background. I will reserve judgement until something a bit more convincing is offered.

    I still can't wait for my own personal air travel. It's coming, but I will believe it when I see it, or can buy it. After all how many times has the Mosler vehicle been on a the cover of Popular Mechanics or another similliar publication?

    "Science is about ego as much as it is about discovery and truth"

  • by Dr Caleb ( 121505 ) on Thursday July 26, 2001 @08:47AM (#2191851) Homepage Journal
    You'll notice from the link: that the 4 engines used are turbo/supercharged Rotary type Wankel engines, like those used in a Mazda RX-7 and RX-8 (2002 model).

    They are cheaper, and readily available.

    The Wankel engine uses 3 cycles/revolution for power, and it's rotation instead of up/down motion of traditional IC engines makes it more fuel efficient.

  • but Wankel rotary engines are about 20% less efficient than water-cooled piston engines. This can be attributed to the combustion chamber on a wankel moving around - more energy is wasted when the case is heated up more evenly.

    They probably make sense in a ducted-fan VTOL machine though - less weight means you need a less powerful engine to provide a controlled descent during engine-out scenarios.

  • The big breakthrough is the new Williams EJ22 engine [], with a 9 to 1 thrust to weight ratio. This is about 2x better than previous technology.

    There's a big NASA-funded push to get the cost of small jet engines down. Jet-powered general aviation would be a big win. Jets are more powerful, quieter, and more reliable than reciprocating engines. They just cost too much to make. This problem is just about to be cracked.

    That's the big news. With cheaper jets, lots of aircraft designs marginal with reciprocating engines will make sense.

    Very, very few people can do really good mechanical design. All the mechanical teletype machines were designed by Ed Klienschmidt. Williams, the designer of the EJ22, designed the jet engines for cruise missiles, and the backpack jet engine for the 1960s flying backpack. He's been responsible for most of the innovation that worked in small jet engines. He's in his 80s. Unclear if anybody can replace him.

  • by Animats ( 122034 ) on Thursday July 26, 2001 @09:35AM (#2191854) Homepage
    Ginger is a self-balancing scooter, using the technology Kamen developed for his self-balancing wheelchair. Gyros, accelerometers, and computers work to keep it upright. Read his patents. He has several variations on this theme.

    D.F. Jones, who wrote the Daedelus column in New Scientist for years, suggested this idea years ago. He proposed one spherical wheel, but you don't really want to do it that way; driving a sphere is a pain if the sphere can get dirty. (Think of the mouse ball problem.) Nor do you want to build a self-balancing unicycle. (A friend of mine at Stanford's robotics lab did that. It works, but there's no neutral position for that geometry, and it works too hard standing still.) Two separately-driven wheels, as Kamen's wheelchair uses, are the way to go.

    There's a lot of noise about a Stirling-cycle engine for Ginger, but I'll bet it turns out to be the standard powerplant for indoor operation - a 4-cycle internal combustion engine running on butane. Thousands of lift trucks work that way. Stirling-cycle engines aren't that efficient.

    The reason it's supposed to be a big deal is that it's a vehicle that can cross the boundary between indoors and outdoors. This could lead to downtown areas with big parking structures nearby but no cars in the built-up area.

    Of course, a skateboard has much the same advantages, except that it requires a skilled operator.

  • Cartercopter! Good Lord I never seen it! This is why keep reading slashdot. I have little resources for it, but this stuff is in my blood. Along with NASA's programs , the Cirrus and Eclipse projects etc. It feels like a long sought renaissance in General Aviation! Potential Aviation Geeks: Know that as we speak, the great pilgimage to Mecca is happening. OSHKOSH!!!: I wish I was there. When I lived in the midwestern US I went every year. Even if you are not into aircraft its truly a hackfest of another color that anyone here would goosepimple at. (If 50 WWII warbirds roaring overhead at once doesn't do it - Lots of workshops, commercial exhibits, NASA, tons of aircraft; homebuilts, experimentals, ultralights, rotorcraft that you can actually examine up close.) It's truly a wonderful event. And if you can't make Oshkosh, there are smaller Airshows hosted by the Experimental Aircraft Association. I just went to the one up here in Arlington WA US and it was great. The EAA is a great organization. These guys are the DIY set of GA and they've kept the open source spirit of grassroots technology sharing since the ENIAC days. Oshkosh! I'm just assuming all active Flying Geeks already know about it or are there.
  • That seems to match up with reason. As they point out, most helicopters and cars average 5 times the cost of their engines. Given their freedom motor spinoff info, the engines are going to cost 2,000$ each initially. Multiply that times 8 engines, that's 16,000$. Multiply by 5... ;)

    -= rei =-
  • 12 years of development? They've been working since, what, the 50s? They've had several models fly. The M400 is the first one that is designed to be mass-produced.

    -= rei =-
  • They have new FAA regulations in the works. If you'll browse around on Moller's site, you'll find that the FAA has already created a new license class (powered lift) for vehicles like these.

    -= Rei =-
  • Am I the only one looking at those choppers and going, "ummm..."?

    110 lbs of depleted uranium? incredibly delicate balance issues? not even the slightest hint of a pricing estimate on the page, or even clues that pricing was a concern at all during the design?

    These are clearly not designed for mass production. They should not be classed in with "skycars", but with helicopters.

    Another thing: their engine is getting less than 2/3 hp/lb. Thats a really poor ratio compared to Moller's, and given their engine setup, probably very fuel inefficient.

    I won't be holding my breath waiting for one of those. I'll wait for my Skycar. :)

    -= rei =-
  • Oh, you could have so much fun with ground lights, or even directional spotlights (strobes? colors? Disco ball?) ;) What would be great would be something like the goodyear blimp had, where you can have it post messages ;)

    -= rei =-
  • Moller's design is fly-by-wire. So, you're not supposed to be devoting your time to piloting it unless something goes wrong.

    I'm sure some light stereo equiptment wouldn't cost too much, weigh too much, or crowd too much :)

    -= rei =-
  • Um, the wankels moller uses are already in use in many other places. Under a DARPA contract, they produced a honda civic designed for fuel efficiency which got 3/4 HP/LB. Their outboard engine, designed for performance, gets 2.5HP/LB. The engines have already been tested - the engine manufacturing company has already had a complete spinoff. Wankels were used for early high performance Mazda automobiles. They were discontinued because their model had weak seals and tended to leak oil, but the engines themselves performed quite well. So, first off, quit accusing people of fabricating data when you don't have any yourself.

    The ones Moller is using for the M400 get over 2HP/LB in the lab (the number they used to brag about), but in the field, the number is actually about 1.5. Still far, far better performance than this chopper.

    Moller has given demonstrations to everyone. Name something they have claimed to have developed but never shown. I'm waiting.

    As for your last point, that may be true, it may not be. But, if you're going to make claims like your former ones, please back them up.

    -= rei =-
  • "will never fly".

    I'll take issue with that. Their past two models have flown out of ground effect. I see no reason to believe this one won't. The question is whether it'll make it to mass production.

    -= rei =-
  • "Yeah, and they ate gas and produced smog at a prodigious rate."

    These were on *race cars* in the *1970s*. The engine itself was only designed during the 1950s - its usage has been skyrocketting since then (the smallest combustion engine in the world is a microscopic wankel engine). Freedom Motors has 500,000 production orders, and they just incorporated. You might as well try and claim that the engines used in (insert some random car) don't work - this is a legitimate company with a legitimate product, that already exists in legitimate on-the-market products, has defense contracts for its use, etc. Do a quick search for 'wankel "freedom motors" engine'. This isn't "Moller's Miracle Engine". This is a Freedom Motors' mass-produced commercially-used-design engine.

    "You mean like that so-called "hover test" which actually shows the thing dangling on a wire?"

    There are several tests. I'm assuming you're referring to the M200, their first model to fly - there's a good video out there of it flying out of ground effect. The "dangling from a wire" is a silly concept - its obvious from the video there is no tension on the thing, its for insurance purposes so they don't get killed if something went wrong (as prototype craft often have unforseen problems).

    "Moller's been working for over 20 years on this stuff"

    Over 50 years. The M200 and the M150 can both hover outside of ground effect. Some of their earlier models can hover within ground effect. They already produce aerobots for defense contracts, as well.

    -= rei =-
  • Well no KIDDING. Every time they have a major breakthrough in the Skycar someone submits it to /. and we end up eating the rest of their development money in unexpected bandwidth charges and toasted-router replacement.

  • by Docrates ( 148350 ) on Thursday July 26, 2001 @08:54AM (#2191867) Homepage
    I just hope Solotrek's vehicle is more reliable and stable than their web server...
  • Valid points, but I think you missed the issue I was trying to address.

    The technology implied in this article are not auto-gyros, but personal flying craft that can literaly 'take off from your drive way'. Now, if they can actually make these craft is another story altogether, but for the sake of the point, I was assuming they can.

    The real issue at hand has to do with the way air traffic is handled. The technology implicit with this kind of craft assumes a greated degree of control that a triditional aircraft does not have. Using your figure of 160 knots for a stall speed (and you don't want run jets in a controled envrionment right at stall speed), there is very little margin for error. (Imagine if cars would blow up if they travled less then 182 miles per hour unless they performed a carefully orchistrated manuvers in special areas). Hence the need for a very advanced air traffic control system manned by experienced, trained professionals.

    Now, take away the required for speed to stay aloft. Take away all the special areas to land, and suddenly you can be far more flexible with how you control things in the air.

  • I don't see this as a major problem here. The majority of current air traffic is difficult to control because it needs to maintain a certian degree of velocity to stay airborn.

    But this technology thows that out the window. If we can get a personal vehicle to cheaply take off vertically and reach high crusing speeds, most likely, we can do it with a large commerical/passenger vehicle. If a 400 passenger literal 'air bus' can land in a city block in your down town, shoot up to 30,000 feet and and then reach speeds close to our current airliners, I doubt the triditional airports (and aircraft) will see much business.

    If we ever get this sort of thing to ever actually work, it's not too unreasonable that in a few years conventional air traffic control will be a thing of the past. While we may not get total automation to prevent people from running into each other, it should be pretty easy to install a GPS in these things with pre-programed 'rules' that govern the piloting style (ie, you are above a city. You can not drop below 3,000 feet unless your hortizontal speed is at zero).

    Of course, just because things CAN be done this way, does'nt mean they should.

  • Airplanes have a rigorous inspection process before each takeoff. This one-person flying machine sounds like a recipe for disaster when the least mechanical failure happens. Plus, there are no wings to save you from free fall!
  • You're posting a fake link, pretending to abuse sourceforge. Why?
  • Do you really think casual users of this kind of craft will have the skill to pull off an auto rotation maneuver []?
  • I doubt such a maneuver could be programmed unless you assume the engine only goes out over an available runway. The maneuver requires that you get as close to the ground as possible before pulling up, at which point there will be some horizontal movement before you fall. Staying close to the ground without hitting an obstacle on uneven terrain is an awfully hard AI problem.
  • What's the story? Well, you were looking at the equivalent of a 1930s Ford Fordor. What you're now looking at is roughly the equivalent of a 1980s sedan. That's roughly the level of technology development, and capability improvement, that have occured in the last 12 years.

    The version you saw 12 years ago, required aviation fuel, carried 1-2 passengers (max), had a top speed of about 90mph, and a range of about 150 miles. And it chugged fuel. Oh yeah - and you had to be a fully licensed pilot to fly it.

    The version you're looking at how runs on normal high-test gasoline, carries 4 passengers, has a top speed of ~400mph, a range of ~900 miles, and gets 15mpg (about what a truck gets). Assuming the FAA goes along, it will only require a cut-down pilots license - about as difficult to get as a truck driver's license.

    Frankly, from where he started 40-odd years ago, Moller has come a looooong way. If I'm right about a couple things, he's also accidentally created most of the underlying technology to make all kinds of variants - a minivan version, for example, could use the same thrust units (doubled-up - you'd need more power), same controls, and a similar aeroshell - and would have the same licensing requirements. Yet you could use it for cargo hauling, or as one hell of an airport shuttle/taxi.

  • by cprael ( 215426 ) on Thursday July 26, 2001 @08:47AM (#2191884)
    You should go read, then. They're not using jet engines, but rather pairs of rotary engines turning fan blades inside each engine nacelle. Basically, it's a variation on what's being done with the V-22, in a civilianized, much smaller package.

    I haven't seen real performance numbers yet from them (they're still using the estimated numbers), but I've been watching these guys for about 12 years now, and I'm hoping they'll get the technology right some time in the next couple.

  • by nick_davison ( 217681 ) on Friday July 27, 2001 @02:46AM (#2191885)
    Using cell phones in the air is already illegal.

    It turns out the network is designed with ground based interference in mind to stop your phone transmitting to too many recievers. Used from the air it hits hundreds of them and it takes relatively few airborne cell phone users to completely wipe out the system. Of course, existing pilots are ignoring these rules in fairly large numbers already.

    So, fair enough these things may start crashing in to your roof at 400mph but at least arrogant jerks (is that redundant when we're already talking about cell phone users?) will completely wipe out the cell network doing far more good to humanity.

  • Well, IANAP (I am not a pilot), but I've got a couple of ideas.

    First off, when you autorotate, it's kinda like you're storing up your lift for when you need it, by reducing the amount of drag you have on the blades to as little as possible.. Well, the closer to the ground you use it up, the more time you have stored up already, thus more lift. Granted, you also NEED more lift at this point, so I'm thinking you'd still have to be lucky.

    Also, let's assume that you ARE a lucky bastard and you will have plenty of lift at whatever point you chose to start autorotating to completely stop your descent and maybe provide a little extra lift so you start ascending! I'm not sure how possible it is, really, but I'm willing to make a couple of assumptions and play with them. My question would be, where would you prefer to use up that lift, 20000 feet up or 20 feet up? Granted, perhaps you could keep autorotating, and come down in short dives. Anyways, I probably don't know what I'm talking about.
  • The trouble is that freedom-motors is basically tooting its own trumpet.

    The flaw: the efficiency of rotary engines is much less than traditional piston engines. The advantages of rotary engines is that you can turn them fast and there's little vibration (turbine-like smoothness). But fuel efficient they are not.

    Moller's numbers are totally unrealistic. Aerodynamic engineers agree there would be colossal inteference drag between the ducted fans and the fuselage of the vehicle. To add to that, he's claiming a fuel-inefficient engine design will do much better than a traditional piston engines. If you work out his numbers, he's claiming the rotary engine will have a better BSFC (brake specific fuel consumption) than the best diesel engines of today.

  • If you're talking about the Moller skycar, you're quite right to be skeptical.

    Moller's performance claims are completely unrealistic. Aerodynamic engineers agree there's going to be a lot of inteference drag from the way the ducted-fan nacelles are set up. Also, rotary engines on a per-horsepower basis are a lot less fuel efficient than even normal gasoline piston engines. Yet his figures indicate they will be more efficient than the best diesel engines being made today.

    Also, you CAN get your own personal air travel. My light aircraft cost half the price of a new Chevrolet Suburban, and burns less fuel too. It does have some limitations, and it was built in 1946, but it's very nice and a great deal of fun to fly. Go to your local small GA airport and ask about learning to fly, or see [].

    Stop dreaming, start flying ;-)

  • I agree with you. The video is completely unconvincing as a claim of flight. The unit is visibly dangling, and its altitude is too steady for the fans to be contributing -- it's clearly being held just where it is by the tether. The web site calls it a hover test, but the unit is not hovering, it's hanging.

    If this were being presented by Transcendental Meditation to demonstrate their claims of levitation, we'd laugh it out of court.


  • by Kraft ( 253059 ) on Thursday July 26, 2001 @09:46AM (#2191900) Homepage
    If you can handle limitations in speed and greater space requirements for landing and take-off, then you can have your own personal motored aircraft for less than 10,000 dollars.

    A paramotor []! Yeps, it's a pretty simple concept - a paraglider (= a steerable parachute) with an engine on your back. Check out pictures [] and real video1 [] and 2 [].

    It sounds experimental, but this is old stuff - pilots have covered 100s of kilometers in this way. There are restrictions on flight over inhabited areas (at least in most of Europe), and you are not able to go much faster than 40 km/h.

    I bought a 2nd hand wing + harness for less than 1,500 dollars, and you can get a good engine for around 5000 dollars. Depending on what wing you get, you can have up to 350 kg. of luggage with you! With the right harness and certificate (or just a liberal country) you can even bring a friend as co-pilot.

    I'm doing my paragliding certificate in Denmark at the moment, and even though I really want a paramotor, cliff soaring still rules.... several hours of natural wind borne flight along the coast of Denmark just beats anything....

  • Well, I really don't understand all this fuz about it.
    First, this is not practical the way it is. Sure, this is a good research step, that _might_ lead to something useful for us all in the future. But this kind of transport is simply not viable for large scale marketing. Imagine the amount of air being moved around by 10 or so of these things. Not to mention the way the air moved by one of these monsters can influence another one near the first.
    Hell, if I want a way to fly, I can just grab a paramotor (or whatever it's called in USA. It's a Paraglider with an helix attached to your back) and just fly around, with much less trouble, and running with much less gas.

  • I don't know about SoloTrek, but the cars Moller is working on look so very cool I can't wait. I'm very curious as to what Moller's vehicle will cost; I couldn't find mention of price on the website. I think maybe its "if you have to ask you dont want to know".

  • It's missing. Check the story from 1999 in USA Today []. I bought a video and info book from these guys years ago and the thing actually worked, although the flight time is really short. Do a Google search for "rocket belt" and you'll get a lot of hits.
  • by wrero ( 314883 ) on Thursday July 26, 2001 @10:24AM (#2191911)
    Paraphrasing: "Cruise at 350 mph from point A to point B" "No speed limits" "No tickets". Totally incorrect.

    The speed limit under 10,000 feet is 250 kias (knots indicated airspeed). So there IS a speed limit. Near any major airport, the speed limit is 200 kias. If the FAA catches you breaking any FARs (aviation rules) you WILL get fined, and you CAN lose your (pilots) license.

    To drive these under present law, you'll need a private pilot certificate. That'll take quite some time, energy, and money; but thank god it will get rid of most of the people who think this is a good idea.

    These vehicles won't help you get to your job in the city, as most cities are under "Class B" airspace (that is, you need clearance to enter), and if the controllers get too busy they won't let all of these new-age commuter pilots in.

    Oh, and weather: Don't expect to drive these things in the rain, clouds, fog, snow storm, etc. You'll need a LOT more training for an instrument rating on your pilot's certificate, and then you'll need clearances to take off and go to your destination. Have you ever sat in a 757 at the gate when the the captian says he's waiting for the takeoff clearance? If these things ever became popular, you'd be sitting in your driveway for hours waiting for your clearance in IMC (bad weather).

    I'll stop ranting now.

  • Everyone seems to be drooling that thisll some day be theirs, but the fact is that if its ever used in our lifetime, itll probably be for police cars ("Pull Over!", coming from above), and ambulances (no high-speed weaving through traffic), and such.
  • by thanq ( 321486 ) on Thursday July 26, 2001 @08:41AM (#2191915)

    I wonder if those vehicles would have to conform to the existing air traffic regulations as far as ID, communication, flight patters, or if new ones would be created. Would there be police patrols on the same vehicles to enforce them?

    Beside the obvious concerns regarding to safety of the commute, I wonder how you could make it cooler. Can't seem to lower it or add alloy wheels to it. I guess you could make the flight stick smaller and put some UV light underneath it, but it's still not the same thing now is it...

  • Finally I'll be able to drive home on that damn gravel without having to wash the car every time it rains! Just fly over it!

    But seriously, you put your average AC "Phl4m3-m4St3R" in one of these and just wait until the deathtoll racks up.

    Or wait. . . .is that a good thing? I mean, sometimes people can survive a head-on collision at 100km/h. If they can do that, it should be a cakewalk to survive a 200km/h collision and then a 100m fall.

    This could officially be Darwin in action.

  • by TheAwfulTruth ( 325623 ) on Thursday July 26, 2001 @08:45AM (#2191917) Homepage
    We have people running over 16 pedestrians while trying to pull out of a parking space. We have teens smashing up 6 cars and one pedestrian while trying to park during a driving test. I can't wait for the RealTV footage when everyone is zooming around at 400 MPH!
  • by dunkerz ( 443211 ) on Thursday July 26, 2001 @08:55AM (#2191922)
    Better enjoy the last years of relatively clear skies, where nature is free to take its course, planes can fly easily, etc etc :) I predict a boom in roof repairs when this technology is introduced ..

  • I might be able to get to the Mall in 10 minutes instead of 50. Big improvement. Now if I could only put two giant lasers on the front of my car and when the pr*ck in front of me is going 350 when the speed limit is 400, I could ...
  • 90mph in a car just wasn't fast enough for me. :) Seriously, this should be able to help alleviate the traffic problems somewhat for those with long commutes like me. Of course I'll probably be dead before it's legal to be used... *sigh*

  • Yes, the age of the Jetsons has finally arrived! When will I get to live in the houses in the sky and have a robot maid?
    The best part of the Moller Skycar: Dual Parachutes

    "No matter how well an engine is designed it has the potential to malfunction at some point during its lifetime. The possibility also exists that something outside the pilot's control, like bird ingestion, could cause an engine or lift fan to fail. "

    That's gonna be fun... :)
    And... Oh damn, where'd that bird come from?! Now I have feathers in my coffee...

Basic is a high level languish. APL is a high level anguish.