Gamera II Team Smashes Previous Best Human-Powered Helicopter Flight Time 118
Zothecula writes "For over 30 years, the $250,000 for the American Helicopter Society's Igor I. Sikorsky Human Powered Helicopter Competition prize has looked decidedly secure, but Gamera II has changed all that. Last week, Clark School of Engineering team pilots came close to breaking one of the competition's major milestones. Ph.D. candidate from Kyle Gluesenkamp from the School's mechanical engineering department, hand-cranking and pedaling like his life depended on it, managed to keep the huge quad-rotor craft aloft for 50 seconds, an impressive new world record that's currently awaiting validation by the National Aeronautic Association (NAA)." We previously covered their attempt to break the record last May.
Gamera is friend to all children! (Score:5, Funny)
Gamera is REALLY NEAT.
Gamera is FULL OF MEAT.
We all love you, GAMERA!
Impressive engineering feat (Score:2, Interesting)
The "flight" was a bit underwhelming. One question about the rules, though. Could you create something that would allow you to store your energy (e.g. spring winding) on top of direct power? Seems like that would help get you off the ground (maybe at the cost of too much weight?).
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Flywheels!
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MILLIONS of FLIES!!
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Billions and billions of flies!!
[/Sagan]
Re:Impressive engineering feat (Score:5, Informative)
That would basically render the whole exercise pointless, because any energy-storage device on-board the craft could be powered by any form of energy. For instance, if you could build a giant 8-seat helicopter and power it with electric batteries, then even a human could "power" it by using an exercise bike to charge the batteries, very slowly, over the course of days or months. I think the whole idea is to make a craft that's so light that a human can power it directly; by storing energy, you can make the craft as big and heavy as you want.
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Realistically it is an interesting exercise (pun intended) in efficient design. Real question is: for a 100% efficient design, of zero mass, how long can the best (i.e., well doped) cyclist in the world stay aloft?
Re:Impressive engineering feat (Score:5, Interesting)
That's a good question. However, as an engineer, I feel obliged to point out that this exercise, while interesting, has absolutely zero practicality or usefulness. Even if you could reduce the helicopter's mass to zero, the amount of energy a human would have to expend to keep himself aloft is staggering. Obviously, a fit human can do it for a minute or three, an athlete like Lance Armstrong might be able to keep it up for 5-10, but that's it; after that, they'll be crashing.
Not only that, this test isn't very realistic as far as helicopters are concerned: they're not far enough away from the ground. Close to the ground, you get the in-ground hover effect, which reduces the amount of power you need to stay aloft. Over 10 feet or so, you go into out-of-ground effect, and then your power requirements increase significantly. In-ground effect is only useful for taxiing to your runway or helipad; if you want to hover anywhere else, you're generally doing it out-of-ground. So even a fit human will have a much harder time keeping that up for long, even with a zero-mass machine. There's a reason birds have hollow bones, and why even hummingbirds (which hover rather than glide) have very limited flight durations, despite their tiny size and mass.
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That's a good question. However, as an engineer, I feel obliged to point out that this exercise, while interesting, has absolutely zero practicality or usefulness. Even if you could reduce the helicopter's mass to zero, the amount of energy a human would have to expend to keep himself aloft is staggering. Obviously, a fit human can do it for a minute or three, an athlete like Lance Armstrong might be able to keep it up for 5-10, but that's it; after that, they'll be crashing.
Also, it doesn't involve spherical cows in a vacuum.
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I don't think so; a larger airfoil has more friction. It's not like you can move some zero-weight airfoil through the air with zero energy; even with no mass it'll still have air resistance. The whole way a helicopter hovers is by forcing air downwards at a rate sufficient to counteract gravity; there's no way that's going to be a low-energy feat, even if you made your craft zero-mass (well, it might be zero energy if the zero-mass craft weren't carrying any passengers or cargo, but that's not too useful)
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You just reminded me of the Lifter Project. There is some cool video of these things, which generate lift from electrostatic effects on the air. Almost totally silent (some hum is apparently sometimes noticeable), no moving parts. One of the experiments even flew a mouse. Lift is apparently on the order of one gram per watt (if I recall from looking into this about five years ago). Contrary to the strong beliefs of some of the experimenters, there is no evidence that it works in space - i.e., it is not
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4.2.3 No drugs or stimulants shall be used by any member of the crew. An assurance must be given to the official observers at the time of the attempt that this requirement has been met.
He's under investigation for using such drugs/stimulants [nytimes.com].
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Yeah, that's why Sikorsky has put up a $250,000 prize [wikipedia.org] for anyone who can fly a human powered 'copter for a minute to an altitude of 3m. Because there is certainly no point in this exercise.
What a crap engineer you must be to have built a wall so close to your face.
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The problem is that the construction they have uses massive amounts of ground effect (note how propellers are lowered to the ground level on the machine, causing it to look massive).
At 3m ground effect will be much weaker. So while this is indeed an interesting advancement, it's not very practical in terms of looking for something that can meet the criteria of Sikorsky's prize. It's too specialized to be dependent on maximum amount of ground effect to scale as altitude increases. The construction that would
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Your bird comparison is quite a bit off. Birds are ornitorpters or mixed combination of both ornitopter and fixed wing (ornitopter on take off, fixed wing on travel for most hawks for example).
Difference between those and rotating wing based helicopter is the massive difference in used energy to stay afloat. There's a reason why US Marines really, REALLY wanted a mixed format of rotor and fixed wing for their troop transport - fixed wing is far more energy efficient then rotating one.
That is also why we hav
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No, I don't think my bird comparison is that far off at all. As you noted, birds/ornithopters are more energy-efficient than helicopters (the more they glide, the more efficient). But even so, they still have to employ a lot of extreme weight-reduction strategies and need a huge power-to-weight ratio. So obviously, helicopters are even worse.
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Not only that, this test isn't very realistic as far as helicopters are concerned: they're not far enough away from the ground. Close to the ground, you get the in-ground hover effect, which reduces the amount of power you need to stay aloft. Over 10 feet or so, you go into out-of-ground effect, and then your power requirements increase significantly. In-ground effect is only useful for taxiing to your runway or helipad; if you want to hover anywhere else, you're generally doing it out-of-ground. So even a fit human will have a much harder time keeping that up for long, even with a zero-mass machine. There's a reason birds have hollow bones, and why even hummingbirds (which hover rather than glide) have very limited flight durations, despite their tiny size and mass.
Yes, this is what I was going to mention. Anyone who flies small planes knows about ground effect [wikipedia.org] (or see 'Ekranoplan' for a large-scale Russian version and some interesting video.) The rotor blades in this test never got more than about a foot off the fIoor. IIRC ground effect applies decreasingly with height up to about the wingspan. Even the 10 foot criteria is still well within the blade diameter, but I wouldn't argue at that point. Of course, it's still a very cool achievement of both technology a
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One thing I've wondered - it seems to me that a rowing motion would enlist more of a body's muscular resources - why use hand and foot pedals?
That's pretty easy. Two reasons: 1) they need rotational motion since it's a helicopter, and it's easy to translate hand and foot pedals, which generate rotational motion, to spinning bladed rotors. Using oars would require more complex mechanics, which might increase weight. 2) hand and foot pedals and bicycle chains are readily available and dirt cheap; you can g
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That would be absurd. You could store an arbitrary amount of electricity up beforehand and run the thing off batteries.
Re:Impressive engineering feat (Score:5, Informative)
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What I would be curious to know is whether muscle tissue is, fundamentally, up to the job(obviously it is for winged flight; but helicopters are trickier). If you dropped the requirement that a human be involved, and allowed the team to get out the scalpel and harvest whatever sorts of muscle tissue they preferred, from whatever species
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Given the (by human standards) alarmingly high power draw, and therefore short duration, of the flight, endurance athletes like bicyclists might not be your best choice...
So get someone used to a short burst of energy instead of an endurance athlete? Seems obvious.
Just as there are marathon runners and 100m dash sprinters, in cycling you have both endurance events such as the Tour de France, as well as sprints, such as what you might see in track cycling [wikipedia.org] at the Olympics. I'd wager that one of them would be ideal for this sort of experiment. And even though a Tour de France rider might not be ideal, I'd still take one of them over a typical grad student. ;)
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Well, duh. A minute is pretty much entirely anaerobic.
You want a guy like this: 500m Lightweight Men's 40-49 Indoor Rowing World Record [youtube.com]
1:23.4 works out to 603 watts on the C2 calculator. Lightweight is 72.5 kg (160 lb) max. He's cranking out 8.3 watts/kg for 85 seconds (assuming peak weight). And he's old.
Tour de France 2011 - Analysis Stage 19 [www.srm.de]
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You have an excellent point regarding design: why not build it around a rowing machine instead of hand-and-feet pedals? It's efficient, and a flywheel should be able to even out the force expenditure... and rowers should be able to take to the thing like ducks to water :)
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Whenever I mention such things to others, they call me a "monster". I say they simply lack vision.
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I think if you went for a sprinter, a cyclist would probably be a very good choice.
I read that Chris Hoy can put out around 1000W for just over a minute. Obviously he weighs a bit more than the student in the film, but I'd imagine he'd have what it takes, so long as he could adjust to the riding position.
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Among the very lightest(manned) helicopters, are the 'ultralights' designed to be cheaper and more broadly accessible by falling below certain thresholds of size and performance that attract more FAA scrutiny. Outside of RC hobby circles, these are about the least powerful, most stripped down, helicopters yo
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It was an impressive achievement, but I don't know that it counts as "flight". In reality, it is a ground-effect craft.
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The "flight" was a bit underwhelming. One question about the rules, though. Could you create something that would allow you to store your energy (e.g. spring winding) on top of direct power? Seems like that would help get you off the ground (maybe at the cost of too much weight?).
If it's a solidly mechanical system, I would call it fair game; Of course, I'm not the judge you would have to impress.
Not sure where (most) the respondents to your query get this obsession with batteries from...
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A bit too solid, and the angles are all wrong (for the rider).
Putting the rider in a reclined position, he's unable to use his body weight against the pedals. Using his arms,he's unable to brace his body to use the full power of his legs (by far more powerful than arms), and by using fixed gearing - the cyclist and the craft reaches max-rpm quickly. Adding gearing would allow the rider to get the rotors spinning with relative ease, then increase the rpm of the rotors by switching gears.
I say:
1. eliminate
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3. make it an 18 speed
This. As soon as I read TFA, I thought the same thing - why no gears? With modern, ultralight materials, proper gearing, and as you mentioned, corrected pilot positioning, I can't imagine a human-powered heli would be all that much of a challenge to build....
Probably wouldn't take a basketball stadium to house the thing, either.
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If you're just trying to get it hovering indoors a few feet off the ground, there's really a pretty narrow RPM band you need to be concerned with. Why introduce the added drivetrain loss (however small) and weight of extra gears?
According to the teams website, they think the extra hand pedaling increases the amount of power the human pilot can put out around 10-20%. Sounds worth it.
As to the recumbent position, I'm just guessing but maybe it has to do with stresses on the frame (which looks like it's barel
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Putting the rider in a reclined position, he's unable to use his body weight against the pedals. Using his arms,he's unable to brace his body to use the full power of his legs (by far more powerful than arms), and by using fixed gearing - the cyclist and the craft reaches max-rpm quickly. Adding gearing would allow the rider to get the rotors spinning with relative ease, then increase the rpm of the rotors by switching gears.
You, sir, obviously don't have much experience in cycling. Recumbent bicycles (where the rider is in a reclined position) are far more efficient than the vertical orientation. So much so that recumbent bicycles are banned from all major cycling competitions (Tour de France etc...) This is because rather than only having the ability to push/pull against gravity, the rider can instead push and pull against the seat itself, allowing them to put out significantly more power, and also be far more efficient be
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You, sir, obviously don't have much experience in cycling.
I quit racing 10 years ago when the road scraped half of my face off. I woke up 2 days later and had no inclination to race again. I did learn an important lesson - the lightest forks are not necessarily the best. Weight be damned, I now only ride on the strongest forks I can find.
Maybe it's a difference in riding styles.... I never liked the feel of recumbent. I use my hands/arms to pull my stroke down when I need the extra power as I described (brace to use the full power of the legs)
When and if they e
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What's the point, if not to build a device to enable human powered flight? Do we consider hovering for 50 seconds "flight"? Maybe the contest goal is satisfied by brief hovering, but I wouldn't be content to work on this project just to win a prize.
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Or maybe they have 30% less wind resistance, which matters not in this endeavor, and that is why there were banned in the 1930's from racing. But hey, you sound good.
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The "flight" was a bit underwhelming. One question about the rules, though. Could you create something that would allow you to store your energy (e.g. spring winding) on top of direct power? Seems like that would help get you off the ground (maybe at the cost of too much weight?).
You need a helicopter parent to help you out with that one.
University of Maryland (Score:5, Informative)
Although the summary doesn't state it, the Clark School of Engineering is part of the University of Maryland at College Park.
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Thank you. I doubt we'll have any tour groups asking where we store the manpowered helicopter and then have to explain to them, no that was some sub-school of another University, but it would be nice if journalists realize that off of a college campus, almost no individual department's name is well known; instead you should refer to the whole institution when reworking a press release from a campus newspaper or website for general consumption.
Get a better cyclist? (Score:4, Insightful)
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Get the pilot some pedal straps for his feet!
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Alberto Contador is available, and no one cares if you slam a bag of clenbuterol tainted blood before the flight.
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Although the way that's written, it doesn't even permit the use of coffee or aspirin. Without an explicit list of banned substances, along with the amounts found in the blood/urine to be considered in violation of the rule, just about every person on the planet could be disqualified.
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A lighter rider like Sagan or Zabriskie might be better.
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Agreed - 50 seconds is a sprint that strongly suggests a training limit. I guess the point of a competition like this is the design of an efficient vehicle, so how about publishing the power requirements (wattage)?
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To optimize you need to find a cyclist with the best power to overall aircraft weight ratio. Then test that cyclist to find the crank length and rpm in which they can produce the most power. Finally pick a gear ratio to match that with your desired rotor rpm.
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Which is what I find amazing about this project, that there is so much room for improvement. The gear ratios are wrong, the pedals are placed suboptimally, and the whole thing shakes like it's falling apart, and yet it still flies. By fixing the flaws this vehicle can be made much better. I guess the reason they didn't use a professional cyclist is that they want to create a helicopter that an average man can ride.
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Paging Alberto Contador (Score:1)
They need another 10 seconds? Call Contador, he probably isn't too busy right now.
A few bites of "steak" later and that record will be smashed, it isn't like the WADA regulates helicopter flights.
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An auspicious moniker (Score:2)
Awe-inspiring? (Score:4, Interesting)
Until then, have a look at the following video of Gluesenkamp's awe-inspiring record flight
I'm sorry, I didn't even realize he had lifted off the ground. Awe-inspiring isn't exactly the word I'd use.
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Until then, have a look at the following video of Gluesenkamp's awe-inspiring record flight
I'm sorry, I didn't even realize he had lifted off the ground. Awe-inspiring isn't exactly the word I'd use.
Not "awe," but rather "awwww... :("
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I was more in awe of the interns whose job is to stand right next to the GYMNASIUM-LONG SPINNING BLADES!
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It just shows you how difficult it actually is to achieve. I thought it was cool and inspiring, especially to see such motivated people, the result of great teamwork, sharp minds, and people who are excited about what they are doing. It's much better than crapping on everything from the sidelines.
Ground effect (Score:2)
Is it a helicopter or just using ground effect? I mean could it fly higher?
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Is it a helicopter or just using ground effect? I mean could it fly higher?
The device in question does appear to be designed specifically to maximize the use of ground effect. The whole machine looks like it's upside-down to get the rotors as close to the floor as possible. However, just because it was designed to use ground effect, doesn't mean it isn't a helicopter. I consider it a helicopter, just not a very practical one.
Kudos to the designer for taking every possible advantage to break the record!
Oh, not THAT Gamera II (Score:2)
I thought they meant "Gamera vs. Barugon," where the giant turtle-monster Gamera smashes all sorts of things, including most of Osaka.
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DARPA is working on that version. A fire-breathing drone, to scare the bejesus out of the natives.
not really practical application (Score:4, Informative)
They're taking massive advantage of ground effect, and are using the distributed rotors to magnify the effect more than a single rotor could. That's probably the primary reason they did so well.
The entire thing seems to be an exercise in futility. Helicopters aren't very efficient. I'd be much more interested in seeing more of the human-powered-glider competitions. Those guys can keep them up in the air quite a lot longer.
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Well, no, human powered gliders are already practical and you can use a bog standard Schempp-Hirth Discus. They do it quite a lot off one ridge in England, basically a bunch of people with a bungee rope sling the glider off the edge of the ridge, and the glider pilot then uses the lift to stay aloft like any other launch method.
For powered fixed wing there has also been the Gossamer Albatross which crossed the English channel.
This on the other hand takes quite a feat of engineering to make something light e
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Full scale helicopters also take massive advantage of ground effect - many helicopters struggle to hover out of ground effect at gross weight. Watch any light piston helicopter take off, and you'll see it lifts into a ground effect hover, then flies in ground effect until it's in translational lift and then some before actually climbing out.
You do not fully understand what you are otherwise accurately describing.
Full scale helicopters do not "take advantage" of ground effect. It is actually a hindrance that reduces its flight capacity.
The reason is that the helicopter is caught inside its own turbulences.
As long as the aircraft is within the ground effect, its flight performances are degraded.
You can find a real-life account of this phenomena, in books such as "Chickenhawk" http://en.wikipedia.org/wiki/Chickenhawk_(book) [wikipedia.org] by Robert Mason or "Ce
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pardon him for he was thinking about hovercraft.
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While ground turbulence is going to detract from peak performance, in level flight helicopters do benefit from translational lift, which increases the weight capacity. On take off, you cannot achieve forward motion until you are off the ground; ground effect helps to gain ground clearance in order to start moving forward under heavy loads. Thus the maximum load can potentially be higher than can be maintained in a hover (not that I'm saying this is necessarily a desirable scenario). In mountainous terrain,
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Motorize it! (Score:1)
Wonder what attaching a small engine to it would be like, something like a 4hp or something...
Before anyone starts whining about "rules" and no stored energy, what do you think Humans run off of? Sunshine and fairy dust? If you like for fairness make it run of ethanol or bio-diesel, both which the unprocessed ingredients could power humans.
I can just hear Dastardly now (Score:1)
"Keep pedalling Mutley, keep pedalling!"
try it naked (Score:2)
not original (Score:1)
Impressive... (Score:1)
smashed? (Score:2)
As amazing as it is, 'smashed' is not a word that I would use to describe besting the previous record. We are just talking about seconds here. They still have to make the altitude to win the prize.
Lever vs. Rotary Crank (Score:2)
I know the gang has put a lot of work into their aircraft. But I submit they need to do a test between the rotary crank they're using for their arm power .. and one or preferably two levers driving a pushrod to a wheel (a la steam locomotive / engine design). I believe a straight fore-aft motion would get much more power out of a human's arms than that clumsy-looking rotary crank motion. And you could coordinate arm and leg motions, so a push with one leg would be countered with a push with the opposite
Re:Holy crap! (Score:4, Interesting)
A somewhat more practical device could be a hydrid airship/helicopter. Keep it heavier than air, but use a hydrogen-filled balloon to counter most of the weight and cycle power to carry the rest. Unfortunately, it would still be large, but the helicopter part could be substantially smaller.
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Hydrogen? Like the Hindenburg?
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Busted on Mythbusters; the paint used to seal the canvas had the wrong proportions, and did not have the same burn rate as rocket fuel. The paints were also layered, and at least one of those layers was fairly fire retardant. If you watch the episode on the Hindenburg, you'll see they did a number of large-scale models, and it really was the hydrogen that caused part of the issue (ANY skin that is at all burnable will cause the same effect when the volume of hydrogen gets large enough). In small-scale, h
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Yeah; it's entertainment and their methodology sucks, but the results of this test were pretty conclusive. Until I see otherwise, it's the best examination I've seen of the Hindenburg disaster to date (and yes, I was grumbling about some of what they did and didn't do -- but they got a few things right and those things point to "rocket fuel paint" not being the major issue).
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Those who cannot remember the past are condemned to repeat it. - George Santayana
PS - Take a look here [wikipedia.org] if you have a problem grasping what I mean with that sentence.
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I figured someone would bring up Hindenburg. Making the balloon skin out of non-flammable material would be a good way of reducing the likelihood of fire.