Human-powered Helicopter Fails to Lift Off

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."

Comments

Wow

[Anonymous Coward]

Wow, a human powered helicopter! Great, I would be free from traffic congestion on my five minute commute to work!

hmmm

[Anonymous Coward]

I dunno, for some reason, the second half of that headline seems pretty predictable after reading the first half :)

Look on the bright side...

[pyrrhonist]

...not getting off the ground makes it difficult to crash.

Re:Look on the bright side...

[Epistax]

If only this were true in software.

I'm all in favor of alternative energy sources

[Anonymous Coward]

But killing humans and using them for fuel? That's horrible!

Re:I'm all in favor of alternative energy sources

[Jeremi]

I find it amusing that liberals are the only ones who say we went to Iraq for oil. We were big customers of Iraq before the war, and we still are. We don't really care all that much about the regime of a country we buy from.

Then why did we go to Iraq? Every reason the Bush administration gave as a justification (WMDs, ties to Al-Quaeda, Iraqis wanted to be 'liberated') turned out to be false, so what does that leave? Was it all really just a colossal mistake? Or did Bush have a deep burning need to "save" the Iraqi people from their government -- so much that he felt the need to distort intelligence and fabricate exaggerated threats to in order to justify his actions? If that is the case, why aren't we "liberating" Sudan right now? (The genocide there is arguably worse, and unlike Saddam's past genocides, there is still time to do something about it)

I don't know the real reasons why we invaded Iraq, and neither do you. All I know is that the official reasons given by the Bush administration don't pass the sniff test, and therefore the real reasons must be something else. Given the Bush administration's penchant for secrecy and doublespeak, and their incestuous ties to the oil industry, it's not a surprise that oil comes to mind.

As for WMDs, the millions of Iraqi dead during Husseins reign as 'president' of Iraq don't bother you? Oh right - malevolent dictators can do no wrong!

The Bush administration claimed that Iraq possessed WMDs that could give America "a day of horror such as it has never known", and that "the smoking gun might be a mushroom cloud". Saddam slaughtering Kurds is a terrible thing, but it has nothing to do with cities being destroyed in the United States. If Bush wanted to invade Iraq based solely on humanitarian grounds, he should have made that argument and let the people decide whether it was worth it. But that was not the argument he made, so it's disingenuous to pretend now that it was.

If God meant for man to fly ...

[Bob(TM)]

... He'd have provided more engineering graduate students.

No pretesting?

[erick99]

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?

[wwest4]

> These blades are huge, thick profile and with HUGE drag.
> There is simply no way a human can spin and keep them rotating
> for 1 minute at a speed sufficient for liftoff.

Yeah, but it's merely an engineering problem. All they have to do is reduce the blade profile by (thick/3.212) to get to (HUGE-SOMEWHATBIG)+3, give or take a few hundredths of a BIG and it just might work.

Could someone confirm my math?

Oh I admit, it LOOKS grim, but isn't it a bit presumptuous to be a naysayer without any real data?

Re:No pretesting?

[Phurd Phlegm]

These were engineering students, and yet no one thought to do the basic physics calculations (like: what is the power required and can a human generate it) before building a prototype. I thought that was what engineering is all about.

I know it's kind of expected that no one on Slashdot reads the references before pontificating, but this (click on "choosing the final Thunderbird design") seems to indicate they did do the calculations and they did expect a human could produce enough power.

It appears they were in error, or that there were other things (e.g., stability) that interfered. That's no reason to expect they won't improve the design and get it working, though. I think it's a pretty cool challenge and certainly beats the usual student project of "design another <known thing>".

Re:No pretesting?

[tgibbs]

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.

Re:No pretesting?

[rtz]

Ugh, people are so stupid. Test things you morons!.

Well, they just did...

Re:No pretesting?

[Dave_B93]

I was at the attempted liftoff.

This was the first time that they had the whole thing assembled, and in some ways you could tell. I think some simple resistance based testing would've shown that chain structure was too fragile to propel the wings properly ( either that or the chain was somehow damaged in the first crash where the blades ran into each other.)

It was also kind of obvious they had never practiced how they were going to start the thing. they had 4 volunteers, (one on the end of each rotor) running around helping the rotors get started. One of the guys on the lower blades was pulling too far down causing the other guy to let go. That is why the blades collided the first time, forget all this not enough lift on the top blade, it was human error.

The second attempt (after repairing the damage caused by the first attempt). looked more promising, the blades actually seemed to be moving quite well, and in fact the upper blade had started producing enough lift that it looked like there was no danger of hitting the bottom one ( even with human error) , but then they ran into the problems with the chain. Imagine the sound that your bike makes when you're in the wrong gear going up a hill. The skipping noises etc... it sounded just like that.

I left after the third attempt when the chain just came off. it didnt' look like they were going to get anywhere, and I'd already been there for about 2 hours.

As for why they'd never practiced with the thing beforehand, I speculate that it is because they didn't know if the thing would survive. If somehow it had gotten off the ground, only to crash after 30 seconds, they would've beaten the record, but wouldn't be able to recreate it. This way they would atleast have witnesses...

They hit eachother!?

[TeVi]

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

[TamMan2000]

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.

Heliman...

[FlimFlamboyant]

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.

Re:Point?

[fireman sam]

The point is that this type of research could lead to more efficient lift mechanisms for conventional aircraft. Allowing longer flights with less fuel requirements.

BTW, the Australian Parlament(sp?) past the free trade agreement, so we now have software patents, yay!

Does strike me as feasible

[AKAImBatman]

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, 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

[Kynde]

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.

Re:Does strike me as feasible

[KjetilK]

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.

Re:Does strike me as feasible

[pclminion]

So, does that mean that no energy is expended holding yourself at the top of a chinup?

There is work being done on a microscopic scale in your muscles. You might need a background in muscle biology to completely understand this, but this is the modern theory of how actin and myosin (the two proteins which make your muscles work) actually cause muscle contraction.

Basically, your muscle fibers are made up of billions of tiny ratchets which cog against another fiber, kind of like a rack-and-pinion steering system. When your muscle is applying force to an object, say, when doing a chinup, the ratchet teeth "slip" and the fibers slide past each other. To counteract this, the ratchets must flex again to pull the fiber back. All this ratcheting work eventually winds up as heat in your muscles.

If your arms were made of steel, it would take no energy to hold a chinup. This is because steel arms have no moving parts. It is important to know that your muscles are indeed still "moving" while holding a chinup, but at a microscopic scale you are not aware of. That's why it requires an exertion of energy to maintain a flexed position.

Re:Point?

[storl]

I'm guessing that the point of this is that a bunch of really bright (ok, maybe not so bright in this case) people are thinking of a way to solve a problem. Think about how useful a human-powered helicopter would be. Not only that, but how many failed attempts were there before the first successful airplane? Maybe someday someone will get it right, and you'll be able to pedal through the air to work. This helps people think up unusual solutions to interesting problems. Having a generation of people that are taught to think shouldn't be a bad thing in a free society.

Design vs Implementation

[sczimme]

IANAAerospace Engineer.

From reading their Project Status/Schedule 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.

Competition rules url

[Andy_R]

here 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.

Re:Point?

[dykofone]

Ah yes, "The Point," what is it and why should anything be attempted if "The Point" isn't clearly defined in a two-page, three-color brochure accompanying a 10 slide powerpoint presentation (with plenty of cute sounds and clip-art) and of course complimentary box lunches.

BECAUSE it's cool, because I look at it and go "damn, that would be quite the engineering accomplishment right there," because college isn't all about inventing things that need to be invented, it's about expanding the mind to accomplish abstract ideas. Think of every lab that students do in their science courses: what's the point of those? It's old technology, it's certainly been done before. Why aren't freshman chemistry students working on cold fusion or something else the military will jump all over?

Besides, this is impressive science, since the human legs can put out a sustainable 100W, it's the attempt to built something light enough to get off with minimal power. And the $175,000 they've spent over 6 years to educate students and built a prototype is cheap in the education world.

Sooner or later someone will do it.

[runner_one]

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.

Re:Will someone hep me?

[D.Throttle]

The team used a counter-rotating design. The outer wing rotates clockwise and the inner wing counter-clockwise. The outer wing which is situated above the inner wing naturally flex and hangs down. It was hanging down to the point at which each wing made contact and shattered into countless pieces rendering thousands of man hours and about $30,000 worth of materials useless.

That should read average human body...

[TamMan2000]

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...

[Overzeetop]

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

Re:Point?

[the_mad_poster]

you know, those strange subjects they used to teach in school before everyone decided they were too hard and made the less bright kids feel bad.

Screw the subjects... I'd be happy if we could at least get back to the point where we're not intentionally holding brighter people back or trying to keep their accomplishments covered up so we don't hurt the dumb and average people's feelings.

The art of flying...

[bsd4me]

The art of flying is learning how to throw yourself at the ground and miss.

Re:The art of flying...

[jcostantino]

Informative? That should be moderated Funny.

Re:The art of flying...

[loucura!]

What about balloons, don't they fly?

Previous attempts at such a prize

[lemonk]

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.

Re:Point?

[Sebadude]

So not only am I paying top dollars to fly to europe, now I'm going to have to pedal for 8 hours too? Great.

Re:Point?

[Anonymous Coward]

Attention passengers, we're preparing for take off. Please put your seats in the upright positions and your feet on the pedals. If you notice a fellow passenger failing to pedal, please quietly alert a stewardess that you suspect terrorism.

At least they proved...

[hcdejong]

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...

blades not stiff enough?

[mks180]

"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.

Re:Why did they bother in the first place?

[Phurd Phlegm]

"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.

Re:Point?

[Tanktalus]

You obviously haven't heard about the Canadian Army's Sea King helicopters which cost $000's per day to maintain. With a human-powered helicopter, Canada could cheaply replace all of its dozen or so copters with these, and gain more maneuverability, speed, and reliability! Even if the thing never leaves the ground...

Re:Wait a second...

[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" since that was now the most obvious short form of my new country. Unfortunately the world has allowed the United States of America to do just this. Of course, I can intentionally annoy the USA and be safe because I know I don't have any WMDs... wait a minute...

Re:Will someone hep me?

[pclminion]

Did you read the article?

"The result was an ugly collision between the two less than one minute after the team made its first attempt at flight, around 11 a.m. Seventeen minutes later -- after a roll of cellophane was used to repair the damaged wing -- the team tried again."

That doesn't sound like massive damage to me, if they were able to patch it up with a roll of cellophane -- in 17 minutes. Sounds like part of the blade cracked or got smashed in, and that's it.

At which point, they continued the test:

"This time, the chain connecting pilot Peter Hudson's pedals to the top rotor snapped. Continued problems with the chain led Georgallis to finally abort the day's mission."

Sounds like they decided to give up before they did any real damage to the helicopter. So, rendering thousands of hours at $30,000 dollars wasted? I don't think so.

People have a way of blowing things way out of proportion, don't they?