Video of a, I think, Dutch guy who claims to have developed a strap-on, flapping-wing flying suit. If the video's a fake it's a good one although one comment I read claimed he didn't see the wing "load up" which means it wasn't developing lift which means it wasn't flying. I'm not so sure. The front half of the wing looks double-surfaced so it wouldn't go visibly taut on the down sweep of the wing.

Have a look:

http://www.wired.com/wiredscience/2012/03/human-bird-wings/

I don't see the wings filling, creating a pocket of resistance when he descended.
I used to fly a hang glider and you need the resistance of pressure under the wing to keep you aloft.

It looks really cool and I hope its not a joke, but ....

Yeah, but with a double-surface wing you wouldn't get the floppiness of a single-surface wing and from about half the chord forward it looks like it's a double-surface.

There are other objections.

For instance, since there's no "breastbone" the lever arm inside the shoulder joint is exceedingly short, compared to the length of the wing on the other side of the pivot point, meaning the forces inboard of the pivot points are exceedingly large.

I guess we'll see.

Double surface wing? There just isn't enough surface area to to create lift.
What do you mean double surface wing, I only see one in the video and can't understand what is being said.

Forward speed has got to be increased dramatically in order to offset surface area and he has neither.
It looks real and I wish it were true, but unfortunately its not.

My thumbnail estimate puts the wingspan at thirty feet. Wing taper isn't great so for purposes of keeping things simple I'll call the wing about three feet from leading to trailing edge. Ninety square feet of surface area, roughly. A second look suggests it's a larger surface area but I'll stick with ninety.

The way he was scampering along before "take off" the wings and drive mechanism couldn't weigh much more then fifty or so pounds. The pilot doesn't look like a hefty fellow so lets say one hundred eighty pounds.

230/90 = 2.5 pound per square inch wing loading. Not exactly "F-104" territory.

I just did some searching and the wing loading of a paraglider I came across was 1.9 lb/sq. feet. Add the effect lift-enhancing effect of flapping the wing and ground speed wouldn't have to be that high to generate lift.

Look, I'm not saying we'll all be flapping down to the local 7/11 this time next week but it's not clumsily obvious that it's a fraud either; not from artifacts in the video or from the layout/size/action of the wing. It might be a fraud but it's a pretty good one and given modern materials and high power-to-weight ratio electric motors I can't dismiss the video out of hand.

Quote from: arpad on March 21, 2012, 06:08:36 AM
My thumbnail estimate puts the wingspan at thirty feet. Wing taper isn't great so for purposes of keeping things simple I'll call the wing about three feet from leading to trailing edge. Ninety square feet of surface area, roughly. A second look suggests it's a larger surface area but I'll stick with ninety.

The way he was scampering along before "take off" the wings and drive mechanism couldn't weigh much more then fifty or so pounds. The pilot doesn't look like a hefty fellow so lets say one hundred eighty pounds.

230/90 = 2.5 pound per square inch wing loading. Not exactly "F-104" territory.

I just did some searching and the wing loading of a paraglider I came across was 1.9 lb/sq. feet. Add the effect lift-enhancing effect of flapping the wing and ground speed wouldn't have to be that high to generate lift.

Look, I'm not saying we'll all be flapping down to the local 7/11 this time next week but it's not clumsily obvious that it's a fraud either; not from artifacts in the video or from the layout/size/action of the wing. It might be a fraud but it's a pretty good one and given modern materials and high power-to-weight ratio electric motors I can't dismiss the video out of hand.

The problem is the volume of air required for lift, he simply doesn't achieve it.
My hang glider had nearly three times the area his wings do, and I still needed lift to keep me aloft, as well as forward motion. (granted, mine was a very early hang glider of the 70s, Seagull)
Its a very well done video, and I have no idea why someone would go to so much trouble to fake it.
But I will stick with it having been faked.

It's starting to look shaky - http://www.wired.com/wiredscience/2012/03/human-bird-wings-hoax/

The article doesn't come out and call it a hoax but that's the general drift of the article. Oh well.

One thing to keep in mind is that the aerodynamics of fixed wing flight aren't directly translatable to flapping-wing flight. Air speed has a different meaning when the wings are articulated since lift can be achieved without forward motion of the aircraft/bird. Not that I'm saying this isn't a fraud, read the Wired piece, just that what's true for the one isn't necessarily true for the other.

Quote from: arpad on March 21, 2012, 03:04:32 PM
It's starting to look shaky - http://www.wired.com/wiredscience/2012/03/human-bird-wings-hoax/

The article doesn't come out and call it a hoax but that's the general drift of the article. Oh well.

One thing to keep in mind is that the aerodynamics of fixed wing flight aren't directly translatable to flapping-wing flight. Air speed has a different meaning when the wings are articulated since lift can be achieved without forward motion of the aircraft/bird. Not that I'm saying this isn't a fraud, read the Wired piece, just that what's true for the one isn't necessarily true for the other.

He is starting to sound like b o, nobody knows him!

Quote from: arpad on March 21, 2012, 03:04:32 PM
It's starting to look shaky - http://www.wired.com/wiredscience/2012/03/human-bird-wings-hoax/

The article doesn't come out and call it a hoax but that's the general drift of the article. Oh well.

One thing to keep in mind is that the aerodynamics of fixed wing flight aren't directly translatable to flapping-wing flight. Air speed has a different meaning when the wings are articulated since lift can be achieved without forward motion of the aircraft/bird. Not that I'm saying this isn't a fraud, read the Wired piece, just that what's true for the one isn't necessarily true for the other.

The part that gives it away for me is the fact that the wings never fill up with air.
Honestly, I wish it were true, I'd love to do this, I'd buy one in a heartbeat.

I posted this on their site.

Its obviously faked, but the bigger question, is why, what is there to gain?
I guess it has much to do with this particular generation, in that mommy and daddy told them they were Spetchal, and there was never a loser in the group, they all got awards simply for showing up.

Later Smeets enters real life and discovers he is not special and never will be, so what does he do?
Creates an elaborate hoax to set himself above the rest of the kids of his very special generation.

Granted, I'll never understand the need for so much attention, this is nothing more than youtubes version of graffiti
He tagged the Internet, oh boy!.

Quote from: walkstall on March 21, 2012, 03:35:39 PM

He is starting to sound like b o, nobody knows him!

Under the assumption that comment's directed at me, uh, no. What I'm starting to sound like is that I've got legitimate responses to Solar's objections to the video which Solar's ignoring.

Flapping-wing flight doesn't require the sort of take-off speed you'd expect from fixed-wing forms since the movement of the wings generates lift at lower overall airspeeds and a double-surface hang glider wing doesn't load up the way a single surface wing does because the design doesn't depend on air pressure to hold the wing camber where it ought to be. That's maintained mechanically resulting in a more refined wing with greater lift and less drag.

As a technical critique of the design, I'd offer that pitch sensitivity would be, inherently, high. With the center of gravity very close to the center of lift, unlike a hang glider, you can't depend on the pendulum effect to damp out pitch excursions. There's no empennage to help out with pitch control so pitch control's going to be entirely dependent on wing deformation control of which isn't obvious.

You can select airfoils that are forgiving of pitch excursions, not changing their center of lift a great deal, but you still have to get the center of gravity pretty close to right to make the "airplane" flyable. Of course with an articulated wing you can change the center of gravity by changing wing position but that's getting to a level of sophistication that the video doesn't even hint at.

Ornithopters though are technically tough which is another mark in favor of fraud. A site dedicated to ornithopters - Ornithopter Zone - lists very few genuinely successful flights and very few successful aircraft.

Quote from: arpad on March 22, 2012, 06:15:01 AM
Under the assumption that comment's directed at me, uh, no. What I'm starting to sound like is that I've got legitimate responses to Solar's objections to the video which Solar's ignoring.

Flapping-wing flight doesn't require the sort of take-off speed you'd expect from fixed-wing forms since the movement of the wings generates lift at lower overall airspeeds and a double-surface hang glider wing doesn't load up the way a single surface wing does because the design doesn't depend on air pressure to hold the wing camber where it ought to be. That's maintained mechanically resulting in a more refined wing with greater lift and less drag.

As a technical critique of the design, I'd offer that pitch sensitivity would be, inherently, high. With the center of gravity very close to the center of lift, unlike a hang glider, you can't depend on the pendulum effect to damp out pitch excursions. There's no empennage to help out with pitch control so pitch control's going to be entirely dependent on wing deformation control of which isn't obvious.

You can select airfoils that are forgiving of pitch excursions, not changing their center of lift a great deal, but you still have to get the center of gravity pretty close to right to make the "airplane" flyable. Of course with an articulated wing you can change the center of gravity by changing wing position but that's getting to a level of sophistication that the video doesn't even hint at.

Ornithopters though are technically tough which is another mark in favor of fraud. A site dedicated to ornithopters - Ornithopter Zone - lists very few genuinely successful flights and very few successful aircraft.

Sorry, I wasn't ignoring them, I just have first hand experience in the area from hang gliding.
It finally dawned on me as to what is wrong with the video.

His legs, they are roughly half the body weight, yet they extend back as if they were weightless.
In a real world situation, the wings would need to be located over the balance point, somewhere around the waist, yet the wings are over his shoulders.
Why aren't his legs dangling?
Truth is, if physics were correct, his legs would still be dangling and he would simply stall and never get off the ground.

Then there is also this little screw up in the video.

Quote from: arpad on March 22, 2012, 06:15:01 AM
Under the assumption that comment's directed at me, uh, no.

No it was from the web site, no one knows him.
http://www.wired.com/wiredscience/2012/03/human-bird-wings-hoax/

And, we're done. The guy in the video admitted it was a hoax - http://www.wired.com/wiredscience/2012/03/birdman-admits-hoax/

Well thats disappointing as Hell.
I thought for sure it would have been to promote something other than his ego.
Then again, I'm really not surprised, it is just another form of tagging.

I'm kind of disappointed as well although not for the reason you gave. I was hoping for a jump on the technology.

The big problem with ornithopters has always been that getting the sort of subtle articulation necessary to get the aerodynamic advantages enjoyed by birds wasn't doable. Complex mechanical linkages and transmissions don't even come close to approximating what a bird does with its wings.

But the last couple of years, with the advent of cheap, powerful, easy-to-interface microprocessors like the Arduino at least the ability to control a mechanical bird's wing has started to show up. But, like all things airborne, you need the whole thing to work, at the right weight, at the same time. So far that hasn't happened but I don't think it's that far up.

But not today.

Drat.