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Australian-Built Hoverbike Prepares For Takeoff
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."
The most epic race series. Get this thing running and get it running NOW!
Hoverbike Applications:
Aerial Cattle mustering
Search and Rescue...
"Flyin' in just a sweet place,
Never been known to fail..."
more like "useless, but cool "
I hope somebody with money to burn backs these guys to get it to actually work.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
Why are you flying so low you can hit a kid anyway?
'Sensible' is a curse word.
Just rev up and give him a hair cut on the way over.
# Airspeed Vne - 150 KIAS (untested)
# Hover (out of ground effect) - >10,000ft (estimated)
seriously slashdot, theres a difference between actual news and pure backyard bullshit.
anyone with even the most remote fucking grasp of physics and flight
should be comfortable debunking his claims as a complete lie.
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..
The CH-47 Chinook twin rotor helicopter is used by the USAF to rescue climbers
on Mount Denali (McKinley) in AK. It can reach an altitude in excess of 19000 to land at an elevation of around 18000.
The biggest problem at that point is restarting the engines,
so a special storage device directs pure oxygen into the engine inlet to restart.
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.
finally, A blackhawk military helicopter with a 1700 horsepower engine still only goes ~190 kias.
Good people go to bed earlier.
And rotational inertia.
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
Sig Follows: "Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself." -- Mark Twain
So there's my flying car. About damned time.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Airplanes have to ability to glide to an extent, helicopters can auto-rotate. I seriously doubt that the rotors on this are big enough to auto-rotate, or that the designer made the calculations necessarily in order to design something that can auto-rotate.
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.
- 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 might have a serious airborne failure. This combined with a massive reduction in total parts (compared to a helicopter) and the hoverbike becomes safer and cheaper.
- Parachutes. With the hoverbike you have the choice to wear an emergency parachute and have two explosive parachutes attached to the airframe, with a helicopter you have no such choice. The hoverbike in it's current configuration cannot autorotate (with adjustable pitch propellers it can) but this should not be viewed as a discredit to the design. Engine failure in a helicopter or plane by no means assures you that you will survive a autorotation or glide, as air crash statistics show. The option of removing yourself from the vehicle and descending via parachute to the ground may well save your life
- The propeller blades will have on the next revision (and certainly the final product sold) a fine mesh over the entire ducting, which will stop any wandering hands or large debri from entering the duct.
WAH! TRIPLE REDUNDANCY WITH FEWER PARTS! ZOMG!
THE OPTION OF REMOVING YOURSELF FROM THE VEHICLE!
I want the optional GIANT GYROSCOPE HELMET!
"Flyin' in just a sweet place,
Never been known to fail..."
http://en.wikipedia.org/wiki/Autorotation_(helicopter)
"Cannot autorotate" is a polite way of saying this thing falls like a rock.
How can I believe you when you tell me what I don't want to hear?
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:
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.
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.
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.
I'd rather take this one, because it isn't vaporware...
"I love my job, but I hate talking to people like you" (Freddie Mercury)
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 blades need to be very slim and low-drag.
Think of the wings of a jumbo-jet. At low speeds for landing, slats and flaps are extended to make a big curved wing. It creates more lift, but it's inefficient. It wastes much more of the kinetic and potential energy of the plane, slowing it down. At cruise speeds the slats and flaps are retracted, making the wing very streamlined and giving it maximum efficiency.
Finally, there's the pitch or steepness of the propeller. The propeller has the lowest drag when cutting the air at zero angle. Of course at that point it doesn't generate any lift either, so the efficiency sucks. When the angle is increased, the prop starts pushing air and creating an equivalent induced drag. The propeller is still almost parallel to the air, so the parasitic drag remains small. Since most of the drag is induced drag at that point, the efficiency is high. If the pitch is increased further, the propeller cross-section against the air increases and parasitic drag goes higher. Sure, it pushes air faster when spinning at the same speed, but since the parasitic drag is high, it can't be spun as fast anymore. High-pitch propellers are used in fast planes, because when the planes move quickly through stationary air, the effective angle of attack of the propeller (the angle at which the forward-moving prop meets the non-moving air) decreases, making it efficient again! In hover applications the prop doesn't move forward through the air at anywhere near those speeds so it's most efficient to use a low angle that provides the optimum lift and minimum drag.
"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
"Flyin' in just a sweet place,
Never been known to fail..."