Australian-Built Hoverbike Prepares For Takeoff 200
Zothecula writes "Adventurous motorcyclists might be familiar with the thrill of getting airborne at the top of a rise, but the Hoverbike is set to take catching some air to a whole new level. With a 1170 cc 4-stroke engine delivering 80 kW driving two ducted propellers, the inventor of the Hoverbike, Chris Malloy, says with its high thrust to weight ratio, the Hoverbike should be able to reach an estimated height of more than 10,000 feet and reach an indicated airspeed of 150 knots (278 km/h or 173 mph). At the moment these are only theoretical figures as the Hoverbike hasn't been put through its paces yet, but Malloy has constructed a prototype Hoverbike and plans to conduct real world flight tests in a couple of months."
This would be (Score:2)
PLEASE KEEP ME STABLE AND HORIZONTAL! (Score:2)
With MAGIC!
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And rotational inertia.
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The one thing I don't get is how do you control roll on this thing. The control surfaces under the ducted fans will give very little if any. If it goes upside down do you just pull the chute?
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"This one goes like a bitch, carving up the road like a frenzied lesbian with a meathook"
-- Jeremy Clarkson, reviewing the new Mini in 2001 [wikia.com]
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I'm not sure either - the center of gravity looks a little high, but the same is true of a Segway - or a bicycle, for that matter - gyro-controlled adjustments of the thrust vectoring might be the answer, or this thing might have similar intrinsic stability to a bike, allowing manual thrust vector control plus rider weight shifting to control roll at speed. The stability in hover would still be a potential problem, even so. With a pitch-controlled prop capable of reversing airflow, together with the right k
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Re:PLEASE KEEP ME STABLE AND HORIZONTAL! (Score:5, Informative)
http://en.wikipedia.org/wiki/Autorotation_(helicopter) [wikipedia.org]
"Cannot autorotate" is a polite way of saying this thing falls like a rock.
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No that means that when the engine stops you plummet like a stone to earth. Unlike most helicopters which if they are unpowered and falling, the propellers will spin and provide some possibility of you not dying when you hit the ground. From wikipedia:
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Yep. Some pilots are so good they say "Watch this" when you're a mile from the landing zone and they shut off their engines.
Then they gently pilot the craft to the landing while everyone else inside pisses themselves.
Been there, done that.
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I'm pretty sure the landing gear is designed to crumple on impact. My buddy's dad was the plant manager at a helicopter manufacturer in Mexico and had lots of auto rotation stories where the pilot and passengers walked away from the "landing".
really? (Score:2)
"Cannot autorotate" means if you lose power to the rotors, you have no lift. ie, you plummet, rather than glide.
ESL (Score:3)
- Very safe. The hoverbike was designed with safety as the over-riding factor in all design. If you have ever flown and pre-flight checked a helicopter you will appreciate the simplicity of this design. With so many parts on a helicopter - and a large number of single parts that could alone cause catastrophic disaster if they should fail - it is just a matter of time. The hoverbike has as many components as possible with triple redundancy which requires at least 2 other components to fail before you migh
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Tangle
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Not a problem. Add a rocket-powered ejection seat. Oh, wait, not in an airframe with an unadorned saddle and a dry weight of 240 pounds. A modern zero-zero egress system probably weighs close to that by itself.
Jetpack?
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Cool, but needs more guarding (Score:2)
I sure wouldn't want to faceplant into the cuisinart on the front of that thing.
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unless it lost lift
those blades probably keep turning even when it grinds you into salsa
Comment removed (Score:3, Insightful)
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Meta rate garbage stories down next time. You're part of the community too ya know.
Re:to clarify (Score:4, Insightful)
Is your average helicopter ducted? No? Then its aerodynamics are not the aerodynamic comparison you're looking for.
This thing is a lot lighter than your average helo, and the ducting makes it more efficient in generating downforce.
Which isn't to say its claim of 10 Kft isn't an unsupportable guess. Just that your arguments are not sufficient to refute it.
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It's supported.
To build on this thought, it's 110kg dry, 20 liters of fuel ~20kg, and me, ~70kg, which is a nice round 200kg. This thing has 295kg of thrust, that's half a g acceleration after overcoming gravity. That's insane!.., that's 0-60 in 5.5 seconds! That's 0-1000ft in 11 seconds. At 10,000 ft there is only 70% air pressure, and 70% of 295 is close to 200 kg, making it the estimated ceiling.
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Think about that again. Ducting increases thrust at any given density. Hence more altitude, if your limiting factor is density.
Regardless, this thing will go nowhere useful without a roll stabilizer.
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So you're saying (if d = density, weight = w, and downforce = f)
ceiling ~ d / (1/f) = d*f/w
so an increase in downforce results in an increase in ceiling?
Isn't that what I said?
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You're telling me 110 horses couldn't lift this thing?
Mythbusters isn't all that swift, sometimes.
And while helis use large blades, have you seen the load you can lift with that blade?
I'm not saying this guy's design will work, but your arguments against it aren't sufficient.
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There is a big difference between the HP at the shaft, and the thrust delivered.
Re:to clarify (Score:5, Insightful)
Because a UH-60 with a max takeoff weight of over 20,000lbs, and a sectional area of a school bus is at all comparable to a single-seater with a max takeoff weight of 600lbs.
In other news, scientists say a 600cc sportbike is faster than an unladen Freightliner tractor powered by a 600 horse Detroit Diesel. Who could have guessed.
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Re:to clarify (Score:4)
anyone with even the most remote fucking grasp of physics
You used 0 physics to rebuke his claim. You only supported your argument with non-analogous airframes.
I don't know if getting to 10K feet is possible with this thing, and I suspect it isn't--it wouldn't be matter of just air density, but also the rider would need protection, like air and temperature controls. Also the horizontal wind speeds would be a whole different factor, and it's not clear that he's taken those into account.
But shit, if it can fly stably at 30 feet at 50 mph that would be good enough for me. I could get off the roads, and therefore avoid traffic and use line of sight to travel.
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Can't speak to the aerodynamics. Maybe dude could just turn his thingy on up on Trail Ridge Road and call it good.
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You used 0 physics to rebuke his claim.
Careful! Maybe he's got a concealed carry permit and one physic in a shoulder holster and another strapped to his leg. The leg one is for close quarters rebutting/rebuking or for after the one in the shoulder holster has been handed over.
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The boiling temperature of water @ 10,000 ft is only about 10 degrees lower than at sea level. For aeronautics purposes anything under 10k ft is mostly the same density. That might be different for a heavily laden cargo plane, but 10k ft is a pretty safe design envelope.
Re:to clarify (Score:5, Informative)
anyone with even the most remote fucking grasp of physics and flight should be comfortable debunking his claims as a complete lie.
From your comments below, I take it you aren't one of those people. Here goes:
most commercial helicopters stall out at anything greater than 8000ft; most of the ones flying around my city stick to around 600-800 ft ceilings..
Those two statements have little, if anything, to do with each other. Helicopters generally stick to low (sub 1,000 ft) altitudes for a couple of reasons -- namely, there's usually little reason to fly higher since it takes more fuel to climb and the jobs for which they are often used tend to require low altitude flight -- not because they are incapable of flying higher. Also, the ceiling for a helicopter is dependent upon its forward velocity through the air. The faster the helicopter flies -- to a point -- the more lift the rotor blades create, and therefore, the higher it can fly, so be careful not to confuse the hovering ceiling with the service ceiling in cruise flight. They are not the same thing.
The CH-47 Chinook twin rotor helicopter is used by the USAF to rescue climbers on Mount Denali (McKinley) in AK.
Uhhh...no, it's not. The Air National Guard based at Kulis in Anchorage flies Sikorsky Pavehawks (militarized S-70s) and the Army at Ft. Rich flies the Blackhawk -- basically the same airframe as the Pavehawk, but outfitted differently. In Talkeetna, AK (where most climbers fly out of to reach Denali), there is a highly modified helicopter nicknamed the "Denali Lama". IIRC, it's an Aerospatiale -- but it's definitely NOT a CH-47. In fact, I'm not aware of anyone regularly flying a CH-47 in Alaska; at least I don't see them in Anchorage very often.
the highest altitude helicopter currently in existence is the AS350. A pilot named Didier Delsalle of France landed it on the summit of Mount Everest (8,850 meters) in 2005...and the record is entirely speculative/disputed.
...which is 29,035 feet [google.com] -- three times the altitude this guy claims for his hover bike. While it may be a disputed record, there are plenty of verified accounts of helicopters landing and taking off well above 10,000 feet in mountain rescues (including Air Force Rescue 470, in which my brother-in-law was the PIC and for which, he won the MacKay Trophy [gpo.gov]).
finally, A blackhawk military helicopter with a 1700 horsepower engine still only goes ~190 kias.
And your point is? A Cessna 206 does 140 knots [cbp.gov] (the article doesn't say on what engine, but 206s typically have either a Continental O-470 at ~235 h.p. or a Lycoming O-520 at ~300 h.p.), but the amateur-built AR-5 will do [ar-5.com] 180 kts [google.com] on 65 h.p. Let's see...the AR-5 has 1/5 the power and roughly 1.5 times the speed. Clearly you can't correlate h.p. to max speed on different airframes. In fact, there's a lot that determines how fast a given amount of power will propel an aircraft, for example, the drag from the rotor disk and how much of that engine power goes into lifting the aircraft. Your 1700 h.p. Blackhawk has a max take-off weight of 23,500 pounds [wikipedia.org], giving a power to weight ratio of 0.07 hp/pound. Since the designer of the hover bike is shooting to classify this aircraft as an ultralight in the U.S., that means he's limited to an empty weight of 254 pounds. [usua.org]
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But does it work on water? (Score:2)
In case I'm being chased by a thug with a meat tenderizer on his head.
Great way to beat automatic photo speed traps... (Score:2)
...although the manned ones would probably still get you.
I don't know how they'd catch you, though...
Aaah.... (Score:4, Funny)
So there's my flying car. About damned time.
Darwin Awards (Score:2)
When I look at the design, its lack of stability and a rider sitting above the fan, only one thing comes to mind - what a perfect candidate for the darwin awards.
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Are your fun circuits malfunctioning? When look at it the only thing that comes to mind is "WANT!"
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Lack of backup (Score:4, Insightful)
You could use a parachute but parachutes take time to deploy and slow your decent so while effective at higher altitudes, at lower altitudes, like say the altitude at which you would be herding cattle, an engine failure would leave you heading towards the ground without enough time to deploy the chute.
I'd fly this is there were 2 engines such that one engine could power both fans, and 1 engine had enough power to at least hover and make a safe decent. Even then, I'd still probably bring a parachute.
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Sounds like it will be most dangerous at the same place as normal helis, low altitude. At high altitudes you can have high confidence that you will have time to ditch and pop your chute.
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How about adding a backup parachute system to the hoverbike itself? That is, it quickly ejects a parachute for the bike and rider when power is lost in the air. Since it's much lighter than a helicopter, it might work. I dunno.
This story works as concept art (Score:2)
It's a beautiful piece of kit. If this were a Deviant Art sculpture project, I'd be in. The fact that these jokers think it'll actually FLY makes it better.
Looking forward to more tests. I also think this thing will kill a lot of pilots. But whatever.
Blade depth is rubbish? (Score:2)
Why don't the blades have a deeper pitch/depth to them. From what I've heard, this increases the efficiency of the wind sucked underneath.
It's the same with cooling fans. Manufacturers (apart from the previous few) always make the blades super thin. It's really dumb, and it causes them to be much louder and waste more energy. Compare:
http://www.skytopia.com/stuff/fan.jpg [skytopia.com]
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that deep pitch is the cup.. and while it allows for more thrust at lower RPM it limits your max RPM which limits your max throughput. it can also cause disturbance behind the blade which can cause cavitation at higher RPM
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For hover applications where the air doesn't need to be moved fast, maximum rotor diameter is always the best, because it lets you move the blades relatively slowly, avoiding parasitic drag (air friction) while still moving a lot of air. That's why helicopters have such big rotors. With this hoverbike, practical matters dictate that the prop diameter is very limited, meaning that in order to move enough air, you need to spin the blades really fast. In order to not waste all energy on air friction, the blade
Awwww, thats sweet Australia! (Score:2)
http://tech.slashdot.org/story/11/05/29/1257212/Martin-Jetpack-Climbs-5000-Feet-Above-Sea-Level [slashdot.org]
"Call that a knife? THIS. Is a knife."
http://www.youtube.com/watch?v=Xqghpm4gXf4 [youtube.com]
There might be regulatory issues in the U.S. (Score:2)
From the FAQ:
From the summary of vehicle regulations for ultralight aircraft at http://www [ultralightflying.com]
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I am pretty sure its stall speed is going to be 0 laterally, and that is less than 28mph, so he may still qualify. Unless of course that stall speed accounts for vertical motion, in which case his is going to be approximately terminal velocity.
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It'd a lot easier to reduce the capabilities to meet regulatory requirement than have to improve something to make it useful.
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Agreed. It wouldn't be hard to shave off capability until it fits the regulatory guidelines. Of course, since the regulatory guidelines aren't built around the idea of a direct-lift rotorcraft which has to expend engine power just to get off the ground, the Hoverbike's at a distinct disadvantage compared to current-technology ultralights. TBH, as you point out, if you shave off enough capability, you've probably eliminated any practicality.
I just thought I should point out the disingenuous handwaving away o
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And, btw, anyone care to speculate what the power-off stall speed of a direct-lift non-autorotating rotary wing aircraft might be?
My answer would be either NaN [codingforums.com] or null. 1) It has no wings, just the ducted fans, so the only airfoil that could stall would be the propellers. 2) If the power is off, the props aren't providing any appreciable lift (since it doesn't auto-rotate). 3) Therefore, the concept of "power-off stall speed" doesn't really apply.
If the power is off, you're making like a brick until/unless you deploy the ballistic recovery chute.
Does Dr. Venture Know? (Score:2)
His two ass-clown sons need a place to rest their no-nos.
*yawn* (Score:4, Informative)
Malloy? Moller? I get so confused... (Score:2)
We'll have to see if this is any less vaporware than the Skycar
http://www.moller.com/index.php?option=com_content&view=article&id=50&Itemid=58 [moller.com]
I'm torn (Score:2)
An Ozzie attempt to cash in on Kiwi success? (Score:2)
To me, the Hoverbike looks like a deathtrap: the pilot is sitting above the lift propellers and with a centre of gravity higher than the centre of lift and no apparent method for lateral stabilization it will tip over the moment the pilot leans to far to one side. In their FAQ, they attempt to brush off the stability issue by talking about fixed-wing aircraft: aircraft that don't hover and that have a la
Odd that the rotors are so small... (Score:2)
Power needed to hover would go down with the square of the rotor diameter. Why not make them, say, 6ft instead of 4ft in diameter -- you'd need less than half the power.
Flash (Score:2)
This website requires Flash to view photos.
Pedantry (Score:2)
Wow, those are some impressive stats. He should be able to hover even WITHOUT the hoverbike.
gizmag?? (Score:2)
controllability (Score:2)
I doubt that (Score:2)
Progressive would insure that ride...
NUMBER 1 APPLICATION!? (Score:3)
Hoverbike Applications:
Aerial Cattle mustering
Search and Rescue...
why? (Score:3)
I hope somebody with money to burn backs these guys to get it to actually work.
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S&R is possible, but flight time on that thing will be extremely limited. if it gets a full hour of flight time I would be impressed.
Military scout patrols might work, I could also see law enforcement uses to work with helicopters.
The big problem on ducted fan machines is fuel consumption. hey burn through too much of it just staying up.
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S&R is possible, but flight time on that thing will be extremely limited. if it gets a full hour of flight time I would be impressed.
What do you do if you are at 10,000 feet, and run out of gas?
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How safe is the Hoverbike? .] .]
* Very Safe. [. .
* Parachutes. [. .
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Galactica 1980 re-enactments.
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Why are you flying so low you can hit a kid anyway?
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Because the gov't isn't going to allow these things to fly unrestricted probably. It really should be called a helibike.
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It's getting classified as an ultralight, so riders won't need a pilot's license.
For whatever *that's* worth
Re:Breaking (Score:5, Funny)
Why are you flying so low you can hit a kid anyway?
The kid is playing hover ball with his jet pack you insensitive clod.
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How exactly to they expect this thing to stop?
I see this scenario playing out:
1. Guy goes too fast on hoverbike
2. Kid runs after ball, runs in front of bike, then realizes the guy is riding at least 50 ft above him, then he gets his ball
3. Bike makes no attempts to stop since it is far above the boy on the street
4. Bike passes kid harmlessly remaining upright and under control
5. Kid looks at oncoming car in horror
6. Mel Gibson runs over kid and yells, "You Abo scum will not grow up to sleep with me wife!
FIFY
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How exactly to they expect this thing to stop?
By hitting a tree.
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I mean who would want to ride in some loud mechanical contraption when the horse and buggy are still around?
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Lots of people [eaa.org] would disagree with you.
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Exactly. All stable, multi-fans have triangle or quadrangle arrangement to create a stable platform.
http://www.youtube.com/watch?v=bxktEwqxbC0 [youtube.com]
Draw a triangle on paper. Next, draw a square.
Very good. Now, draw a line.
If the problem doesn't leap out at you immediately, you are lacking in the ability to perform some very basic assessments.
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http://www.youtube.com/watch?v=c4Ul6-mQh8g [youtube.com]
You want only two? They better have the "wingspan" of a Chinook!
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In comparison, with the Hoverbike, "Contrary to popular belief, having greater mass above the centre of pressure does not mean an unstable craft (yes it is less inherently stable than below)." [hover-bike.com]
Or, in the immortal words, "one of these things is not like the other."
I expect that the Hoverbike is has about the same static lateral stability as a real bike: not very much. I suppose you could market it a
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Or more importantly, the Chinook has swash plates, so the rotors themselves can roll the aircraft.
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I've actually done a little experimenting with the gyroscopic effect of a bicycle wheel. It has to be spinning very fast or be artificially heavily weighted to be have forces large enough to help keep the bike upright. In actual practice, it doesn't help at all. If you don't correct with steering or balance changes, no amount of gyro force is going to keep a bike upright. Furthermore, the spinning wheel also opposes the turning of the handlebar which is the cyclist's primary tool for keeping a bike upright.
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What is this guys hoping this thing will fly on, hopes and prayers?
According to TFA (I know, I know...what was I thinking?), with gyroscopes.
In related news ... (Score:2)
Scientists expect a breakthrough "when pigs fly".