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Education Technology

Human-powered Helicopter Fails to Lift Off 410

Posted by michael from the we've-got-hiiiiiiiiiiigh-hopes dept.
Peter writes "The Human-powered helicopter didn't even get off the ground. A team of University of British Columbia engineering students tried to win the $20,000 US prize offered by the American Helicopter Society. Three metres off the ground and hover for a minute was the challenge. But before the rotors were able to produce enough buoyant force they hit each other. More details: Vancouver Sun."
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Human-powered Helicopter Fails to Lift Off More

Human-powered Helicopter Fails to Lift Off

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  • Wow (Score:3, Funny)

    by Anonymous Coward on Friday August 13, 2004 @09:38AM (#9957941)
    Wow, a human powered helicopter! Great, I would be free from traffic congestion on my five minute commute to work!

    • Re:Wow (Score:2, Funny)

      by RevDobbs ( 313888 ) *

      I see... a methane burning engine, and "U of BC Engineers Go To Taco Bell".

      I'd bet ya that a couple of Chimichanga Burrito Supream Stupidbigs would induce one human to produce enough methane to power a small 'copter for a 5 minute trip.

    • Yeah, but I bet you wouldnt want to be seen flapping your arms vigorously and failing to lift-off!

  • hmmm (Score:4, Funny)

    by Anonymous Coward on Friday August 13, 2004 @09:41AM (#9957971)
    I dunno, for some reason, the second half of that headline seems pretty predictable after reading the first half :)

  • Look on the bright side... (Score:5, Funny)

    by pyrrhonist ( 701154 ) on Friday August 13, 2004 @09:41AM (#9957976)
    ...not getting off the ground makes it difficult to crash.

  • That's just silly (Score:2, Funny)

    by Anonymous Coward
    Everyone knows Canucks can't fly.

    So no simulations or models or just spinning the rotors indicated this might happen?
  • "Right now we're all taking bets on what's going to fail first"

    Sounds like this venture was well planned!

    • Re:Why did they bother in the first place? (Score:4, Insightful)

      by Phurd Phlegm ( 241627 ) on Friday August 13, 2004 @10:27AM (#9958455)
      "Right now we're all taking bets on what's going to fail first"
      Sounds like this venture was well planned!
      Actually, that's how you engineer something for the lightest possible weight. If nothing fails, you've overbuilt the whole structure. If something fails you beef that part up a little and try again. I imagine that light weight is really critical with this design, even if you can find a really brawny little bike racer to pump the thing. One of those guys that basically a pair of legs supporting a pair of lungs . . . .

      Of course, you do it differently if there's human life involved, but I can't imagine a human-powered helicopter getting high enough for this to be a major concern.

      • ... the first human-powered cross-Channel flight. I know one of the guys who was on the support boat for it, and who was heavily involved with the project. They figured it was easier to get a cyclist and teach them to fly an aircraft, than to get a pilot and train them up as a champion cyclist.

  • I'm all in favor of alternative energy sources (Score:5, Funny)

    by Anonymous Coward on Friday August 13, 2004 @09:42AM (#9957990)
    But killing humans and using them for fuel? That's horrible!
    • *calls engine room* Put on more humans!

    • Here's your fuel cycle:

      Human -> Liposuction unit -> Biodiesel unit -> engine...

      The challenge then becomes one of shrinking the intermediate stages between human and engine. Fat is our highest energy density but we don't have the power density in our natural fat burning processes, hence, time for a little help from technology.

      It would make the invention practical for most Americans. Maybe fast food chains would get behind the project... :-)

  • If God meant for man to fly ... (Score:4, Funny)

    by Bob(TM) ( 104510 ) on Friday August 13, 2004 @09:42AM (#9957992)
    ... He'd have provided more engineering graduate students.

  • No pretesting? (Score:5, Insightful)

    by erick99 ( 743982 ) <homerun@gmail.com> on Friday August 13, 2004 @09:43AM (#9957998)
    How could they not know that this was going to fail so completely? The article did not state whether or not they had done any test flights before the public demonstration. If they did, and it worked, than maybe it was just the temp/humidity as stated. It was interesting to read:

    "My feeling at the moment is that the machine is actually quite unstable," said Mike Georgallis, leader of the team that has been working on the project for six years.

    Maybe they did know that this wasn't likely to be a success.

    Cheers,

    Erick

    • Re:No pretesting? (Score:5, Insightful)

      by tgibbs ( 83782 ) on Friday August 13, 2004 @10:39AM (#9958599)
      How could they not know that this was going to fail so completely? The article did not state whether or not they had done any test flights before the public demonstration. If they did, and it worked, than maybe it was just the temp/humidity as stated. It was interesting to read:

      Very probably, they didn't really expect it to work the first time (although I'm sure they had hopes). But hey, it's a university, so there's no real reason to hide the failures behind closed doors, and good educational reasons to do it in public. After all, failing and going on is a legitimate part of the development process.
  • as a consultant(or maybe the people that infused him with the powers, I can't remember who)..

  • They hit eachother!? (Score:5, Funny)

    by TeVi ( 128093 ) on Friday August 13, 2004 @09:43AM (#9958007) Homepage
    Peter writes "The Human-powered helicopter didn't even get off the ground. A team of University of British Columbia engineering students tried to win the $20,000 US prize offered by the American Helicopter Society. Three metres off the ground and hover for a minute was the challenge. But before the rotors were able to produce enough buoyant force they hit each other.

    I assume 'they' refers to the rotors, not the team...

  • Nitpick (Score:5, Insightful)

    by TamMan2000 ( 578899 ) on Friday August 13, 2004 @09:44AM (#9958013) Journal
    This is kind of a nitpick, but buoyant force has nothing to do with how helicopters work, blimps and boats use buoyancy, helicopters and planes use aerodynamic lift.
    • Technically though... isn't it? The helicopter is buoyed up by the pressure differential across the rotor. It's just instead of a water-air, or air-helium boundary, we have an air-air boundary... Does that count?

      -Jesse

      • Re:Nitpick (Score:3, Informative)

        by kidgenius ( 704962 )
        Techincally, buoyancy force is the total volume of the fluid displaced multiplied by the density. That is how "lighter than air" craft are able to stay aloft. Aircraft, use lift.

  • Heliman... (Score:3, Interesting)

    by FlimFlamboyant ( 804293 ) on Friday August 13, 2004 @09:44AM (#9958017) Homepage
    Does this mean Lance Armstrong will soon become an astronaut?

    I've seen machines in the past that are glider-based, and a human could actually keep them in the air for a fairly long time. But a helicopter? I wonder what they're trying to accomplish here. I mean, obviously the students are trying to win $27,000, but I have to wonder what the American Helicopter Society is thinking. Vertical flight always consumes a heck of a lot more energy than horizontal. I'd like to see more effort put in to human-powerd glider projects.
  • but then we got hiiiiiigh!

    Just goes to show kids that the evils of marijuana make you fail at everything! Even making yourself fly high!

  • Does strike me as feasible (Score:3, Informative)

    by AKAImBatman ( 238306 ) <akaimbatman AT gmail DOT com> on Friday August 13, 2004 @09:46AM (#9958038) Homepage Journal
    A normal helicopter needs several Kilowatts of engine power to produce enough lift to even get itself off the ground, much less loaded down with a human. The human body constantly generates an approximate 200 watts. In case anyone's wondering, that's about 0.26 horsepower [slashdot.org], and that's assuming that you can apply the full 200 watts of your energy.

    It's fun to see them try, but the physics say that the energy just isn't there. Perhaps if the copter weighed almost nothing, and it was constructed of super-strong materials. Of course, then we'd have unobtainium. :-)

    • Re:Does strike me as feasible (Score:5, Informative)

      by Kynde ( 324134 ) <kynde@[ ].fi ['iki' in gap]> on Friday August 13, 2004 @09:55AM (#9958137)
      The human body constantly generates an approximate 200 watts. In case anyone's wondering, that's about 0.26 horsepower, and that's assuming that you can apply the full 200 watts of your energy. It's fun to see them try, but the physics say that the energy just isn't there.

      That's not entirely accurate. I think the 200 watts is an approximation of the heat we emit in room temperatures. That's not the only source of power we have. We can also, for example, pedal.

      Considering that we can run uphill fairly fast, the physics indeed says the power to overcome gravity most certainly is there, atleast for short periods of time. It's another question entirely wether we have the power to lift ourselves and the helicopter machinery using that technique. It will mostly depend on the efficiency vs the weight of the machinery.
      • >Considering that we can run uphill fairly fast, the physics indeed says the power to overcome gravity most certainly is there, atleast for short periods of time.

        (Sorry if the following is confusing or hard to read, as I realize that english might not be your first language.)

        Isn't running up hill, just breaking gravity for tiny (~2 secs) at a time? Each step you take is breaking gravity, but then it reclaims you as shift weight from one foot to another?

        Would a better example be doing a chin-up and ho
    • A human generally is lighter than a combustion engine.

      Look at the Vancouver article, the helicopter looks more like a glider.

      And couldn't they store up the energy into a big rubber-band, by ten minutes of human energy, let it go and add more energy as it goes up?
      • its one of the rules for the competition. a big rubber band would violate the rule and disqualify them.
      • A human generally is lighter than a combustion engine.

        Here is a helicopter [rotor.com] with a dry weight of 254 pounds. It's engines generate 55 horsepower (41 kilowatts [google.com]) to get itself and one passenger off the ground.

        And couldn't they store up the energy into a big rubber-band, by ten minutes of human energy, let it go and add more energy as it goes up?

        Of course. Watts is only a way of measuring constant energy flow. Convert to Joules and you can figure out what it would take to get off the ground. e.g. If we s
        • Even that lightweight helicopter has extra mass that could be shed. get rid of the floats, the windscreen, body, etc. Reduce it to nothing but a frame. Is it still highly unlikely? Yeah. Though I'd imagine that if they would instead use a much thinner wing, made entirely of carbon fiber or something, that they could have a very efficient, very light wing that they could spin very fast. Those blades on their helicopter are huge. I'd have trouble believing that there are too many engines out there that

    • That should read average human body... (Score:5, Interesting)

      by TamMan2000 ( 578899 ) on Friday August 13, 2004 @09:58AM (#9958169) Journal
      The human body constantly generates an approximate 200 watts

      You mean the average human...

      Lance Armstrong can sustain power outputs around 600 watts, and several people (most competative amatuer cyclists) are capable of a ~1 minute burst of over 1250 watts.

      • Re:That should read average human body... (Score:5, Interesting)

        by Overzeetop ( 214511 ) on Friday August 13, 2004 @01:49PM (#9960848) Journal
        Yes, that's true. In fact, most healty indivduals can generate more than a horsepower (746W) for very short bursts. To prove this to yourself, find a flight of stairs and time yourself running up them:

        Your weight in lbs x floor to floor height in feet / seconds to climb / 550 = horsepower

        Don't live in the US?
        Your mass in kg x 9.82 x floor ht in meters/ seconds to climb = watts

    • I don't know where you got that figure, but you may want to look at the sustained power output of a cyclist. I am an average cyclist, and I can pump out more than 200 W sustained if it's for only a few minutes. For comparison, the Tour winner cranked out around 350 W average for the whole tour, and is capable of much more. (of course, power/weight ratio is what really counts, but the same argument applies).

    • In case anyone's wondering, that's about 0.26 horsepower, and that's assuming that you can apply the full 200 watts of your energy.

      They should have used a quarter horse [quarterhorse.com]? (I _really_ don't want to know where the term "pleasure horse" came from...)

    • Re:Does strike me as feasible (Score:5, Insightful)

      by KjetilK ( 186133 ) <kjetil AT kjernsmo DOT net> on Friday August 13, 2004 @10:14AM (#9958321) Homepage Journal
      RTFWS... I have personally small problems sustaining 400 Watts over a period of a few minutes, and I can probably get somewhat higher since I have a pretty good anaerobic capacity.

      They have done their tests, and they have a guy which can do well beyond 500 watts, that's a lot.

      The next thing is of course to make the helicopter lighter, and optimize everything for efficiency.

      At some point, energy demands will get low enough, and then you may have liftoff. I think you're a bit too pessimistic. It's not easy, but that's not why they do it.

      • 500 watts is a lot for a human. But it's also something most humans can only do for short bursts. i.e. Your body stores up glucose for when it's needed. As long as you're stored glucose is being burned, you can reach potentially huge increases in physical power. But once the glucose fuel is exhausted, your power ratings become dependent on your body's ability to produce more glucose. This ability goes down as the lactic acid builds up in the muscles, making high levels of production that much more difficult
      • Hmm. When it comes to power produced on a bicycle, there's one obvious place to look...

        http://www.lancearmstrong.com/faq.html [lancearmstrong.com] points out that Lance produces around 250 watts during an endurance ride (2-4 hours). For sustainable travel, I think that we can comfortably state that most potential helicopter pilots will not be in better shape than Lance.

        His burstable power is around 600W, but there's no point in being able to get yourself 30 meters up off the ground and then need to take a break for a minut
    • Not to sound like someone taunting the Wright brothers, but seriously, this sounds freakin' impossible.

      The only way I can imagine this working is with a really strong spring that weighs almost nothing being used to store a few hours of pedaling, to be released over a period of 3 minutes. Maybe in 100 years, when we have nano-technology to make everything out of carbon-nanotubes and diamond monofilament, okay, maybe then. But from the looks of it, they'll add that to the "cheats" list.

      I'm surprised they di

  • Design vs Implementation (Score:5, Interesting)

    by sczimme ( 603413 ) on Friday August 13, 2004 @09:47AM (#9958044)

    IANAAerospace Engineer.

    From reading their Project Status/Schedule [mech.ubc.ca] page, it appears their problems may have arisen during the manufacturing stage:

    July, 2004

    It has been a while since our last update. We have been busy.

    COMPOSITE SPAR MANUFACTURE/TESTING

    All spars have been cooked including the tapered sections. Assembly of all this is complete for the four wings. Static testing was carried out for the assembled spars. All four eventually passed the test (see Thunderbird Projects - Picture gallery).

    WING CONSTRUCTION

    All four wings (for the two rotors) have been completed. This includes all wing parts (leading edges, trailing edges, suction side, ...) and assembly (see Thunderbird Projects - Picture gallery).

    "Eventually passed the test"? Uh oh.

    [There were no updates from December 2001 to July 2004]

    December, 2001

    COMPOSITE SPAR MANUFACTURE/TESTING

    Static testing has been carried out for the CFRP spars. Static tests included both bending and torsion. A large effort was put in manufacturing the tapered mandrel for tapered composite spar production. One tapered spar has been manufactured with disastrous results. The tapered mandrel still requires some work (modifications). Composite spar manufacture continues (including straight sections).

    It appears there were construction issues early in the project.

    I am certainly not knocking their efforts. However, even the most elegant design can be compromised by sub-optimal manufacturing/implementation resources. I wish them the best in the next iteration.

  • What a shame (Score:2, Insightful)

    by azbot ( 544794 )
    Wow did you see the size of the rotors on that thing?

    Its a real shame that it didn't work, sounds like the team have been working on it for a long time, which makes me wonder, wheres the tail rotor?

    • Re:What a shame (Score:2, Informative)

      by dykofone ( 787059 )
      Counter-rotating rotors, a lower set goes one way (let's say clockwise) and the set above it goes the other way (let's say anti-clockwise).

      The torsion created by each set of rotors balance out, preventing the need for a tail rotor to prevent spinngin. It was one of the upper rotors that hit the lower rotors in this case, which is thought to be due in part to heat and humidity (probably since the top rotors were longer, the heat and humidity caused them to bow, and they didn't generate enough lift to pull t

  • Competition rules url (Score:5, Insightful)

    by Andy_R ( 114137 ) on Friday August 13, 2004 @09:49AM (#9958064) Homepage Journal
    here [vtol.org] are the rules of the competition.

    The obvious cheats (lighter than air gases, storing energy in a battery) are banned, but you could 'cheat' by using a human to store up a lot of energy in a low-drag rotor that then changes angle of attack to convert the stored energy to lift.

  • Sooner or later someone will do it. (Score:5, Insightful)

    by runner_one ( 455793 ) on Friday August 13, 2004 @09:51AM (#9958098)
    Never underestimate the power of human ingenuity. For many years the thought of sustainable human powered flight of any kind was considered an impossibility but in 1979 we saw the Gossamer Albatross cross the English Channel. I believe that sooner or later someone will manage to meet the requirements to win this American Helicopter Society prize. However without a doubt even then human powered flight will be just an interesting curiosity and not of any practical use.
  • and no one caught such a simple design flaw.

    All they had to do was have the outer wing on the bottom.

  • The chain broke? (Score:3, Funny)

    by 955301 ( 209856 ) on Friday August 13, 2004 @09:52AM (#9958109) Journal

    I would suspect they would have to have gears to get the rotors up to speed but, judging from the picture, I guess they figured the pilot had enough to do, what between holding on for life, pedaling, and praying to the gods.

  • Possible? (Score:3, Interesting)

    by telemonster ( 605238 ) on Friday August 13, 2004 @09:57AM (#9958150) Homepage
    Is it possible someone did the math and figured out people can't generate enough lift to keep themselves in the air (the more people you add, the heavier it gets).

    So once they figured this out, they thought it would be funny to watch people try? I'm having flashbacks to the movie "Chicken Run."

  • How much difference would there be in air pressure between the top and bottom of each rotor?

    It's been a while since my last fluid mechanics class, but wouldn't the low-pressure above the bottom rotor "suck" the top rotor downward every time the two rotors overlapped each other while spinning?... causing the top and bottom rotors to bounce (if ever so slightly) up and down?

    • I think the low pressure from the top of the bottom rotor would have eliminated the high pressure below the top rotor, disabling the top rotor's ability to produce lift.

      Since the top rotor wasn't producing lift, the rotor would sag, while the lower rotor was, and straightened out, and *crunch*...

    • can't be all that bad... (Score:3, Informative)

      by bani ( 467531 )
      ...russians are rather fond of using the dual counterrotating design.

      http://www.airliners.net/open.file?id=056899
      ht tp://www.airliners.net/open.file?id=123084
      http:/ /www.aeronautics.ru/kamov/ka5201.jpg
      http://www.a eronautics.ru/archive/vvs/ka27-01.htm
      http://www. zap16.com/mil%20fact/kamov%20Ka-50.htm

  • My easy solution... (Score:2, Insightful)

    by TheCaptain ( 17554 )
    The weight isn't as important as a little forethought.

    It has to be human powered? Fine...put Joe Powersource on it...let him peddle like mad. Store that up in a flywheel or other such reservoir. Let Joe keep peddling one more minute while you tap the flywheel to get the darn thing in the air and help hold it there for a minute.

    Eh...then again, I didn't read the rules for this thing - but I'd be looking for the easiest solution the rules will allow rather than the most elegant one. You are trying to wi
    • I would put some weights on the ends of the rotors and have them start off in a non-lifting angle of attack. Then, when they're up to speed, angle them the right amount up and keep pedaling. Much better than a dedicated flywheel.

  • Previous attempts at such a prize (Score:3, Interesting)

    by lemonk ( 220326 ) on Friday August 13, 2004 @10:07AM (#9958254) Homepage Journal
    I was a member of a team way back in around 1993 that was going for the Sikorski Challenge, which I believe was similar to this one. At the University of Illinois at Champaign-Urbana our project, named the X-391 Dragonfly, was to hover at 1 meter for I forget how many minutes. We got as far as building the main rotor from carbon fiber/kevlar/foam injection with a custom made oven/vacuum bag contraption as well as designing the 'cockpit' the rider would sit in. It was a great experience even if it never "got off the ground" pardon the pun.

  • Human Helicopters (Score:3, Interesting)

    by justanyone ( 308934 ) on Friday August 13, 2004 @10:08AM (#9958261) Homepage Journal
    I believe the only way we could create human-powered aircraft is when the components (mostly wing area) was large and light enough to overcome thrust-drag ratios.

    POINT 1: Can someone comment on the maximum sustained (3 minute duration) power output of a well trained human body? I believe it's less than one horsepower... ("he was stronger than a horse"), but not by much.

    Regardless, it seems to me the components on a controllable helicopter include a Sikorski rotor assembly (that allows different angles to be put on a blad depending on it's position in a rotation). That dictates towards rotor blades that can occilate rapidly, and thus can very strongly stand up to high-speed torsions as well as flexing.

    POINT 2: Since the blade structure is complex, and the rotors must be quite powerful, it seems to me that dictates tight restraints on design given the weight must be severely limited. Is there any discussion of exotic materials used in any other news article? I suspect a lot. What would the rotor blades be made from, standard materials like commerical helicopters?

    POINT 3: I suppose the competition prevents someone from using a power storage device like a big battery or flywheel that a person can pump up to accumulate energy?

    POINT 4: Does "Human Powered" mean chemically? Suppose I dried and accumulated enough of my own "dung", then burned it to distill alcohol, then used that alcohol as fuel in a conventional helicopter, it would be "human powered"... (grin).

  • At least they proved... (Score:5, Funny)

    by hcdejong ( 561314 ) <hobbes@@@xmsnet...nl> on Friday August 13, 2004 @10:18AM (#9958358)
    that the theory "helicopters can't fly; they're just so ugly that the Earth repels them" is incorrect. Oh well, back to the old drawing board...

  • Damn (Score:2, Funny)

    by Monkeyman334 ( 205694 )
    I guess there goes my dream of being a human powered .. helicopter ... pilot. Soaring through the ... 3-meter-sphere. Okay, nevermind.

  • Wait a second... (Score:3, Funny)

    by RealErmine ( 621439 ) <commerce@nOspaM.wordhole.net> on Friday August 13, 2004 @10:22AM (#9958401)
    A team of University of British Columbia engineering students tried to win the $20,000 US prize offered by the American Helicopter Society.

    Since when is Canada part of America?



    =)

    • Re:Wait a second... (Score:3, Insightful)

      by Anonymous Coward
      Uhhh... Since when is "America" only the United States of America? In most parts of the world, "The Americas" stretch from the southernmost points in Chile to the northernmost parts of CANADA.

      It always ticks me off when "Americans" think that "America" is the name of their country. I mean, if I were to form a country in Europe, and call it the "United States of Europe", I would have a heck of a time convincing the rest of Europe that they weren't Europeans, and they could no longer be part of "Europe" s

  • blades not stiff enough? (Score:5, Interesting)

    by mks180 ( 442267 ) on Friday August 13, 2004 @10:24AM (#9958417)
    "the atmospheric conditions caused a dangerous imbalance in the craft's two rotor blades: the bottom blade was producing lift while the top blade wasn't." Sounds to me that what really happened was that they tried to save weight and didn't make the upper blades, which are longer, torsionally stiff enough. This caused a phenomenon similar to aileron reversal: as you produce lift, you produce a nose-down pitching moment which can elastically twist the blades, and may be capable of reversing the direction of lift. If this is what happened, then I can easily see the upper blades flapping down into the lower set of blades.

    This aileron reversal effect is actually a fairly hot research topic in the rotorcraft community. People are trying to exploite it by using embeded actuators to control trailing edge flaps to create a pitching moment to twist rotor blades and thereby eliminate the swashplate for primary control.
  • I think someone would produce more spectacular results if one were to build a rocket onto a Schwinn like Bob Lazar's www.unitednuclear.com/jetplans.htm

    and add wings...

    then again, maybe it was Bob on a flying Schwinn, over Area 51, after all.

    Props to Bob and his alien craft reverse engineering!
  • Since you only have to store then energy for a minute, why not use a gearing system to store energy into a flywheel and then release it to supplement what you are still generating for the 3 minutes. you would also have to use variable pitch propellers or possibly a gearing system that allows you to charge it without moving the blades.

  • Crazy (Score:2, Interesting)

    by PingPongBoy ( 303994 )
    Two rotors? The blades are so big the drag will make it really hard just to sustain RPMs. If the rotors have independent speeds of course they will smack each other given they are nearly in the same plane.

    Can't tell from the pictures if there really is a gear shift but it doesn't look like it.

    Add a gearshift and use one pair of lift blades as well as a tail rotor

    Shorter blades are likely better. The long blades may require fewer RPMs but the tips of the long blades will be really moving (v = wr) anyways.

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