Landing a wingsuit

[quade 4]

Dan --
Yeah, that's basically where I was going with my rough order of magnitude line of reasoning.
Luigi says he's flown a canopy at 4.2:1 and you're saying 3.7ish:1. Let's make it an even 4:1 just for the sake of argument. Let's also say that was a about a 40^2ft canopy so figure about 160 lbs out the door.
If the current largest wing suits are about 9^2ft then 160/9 = 17.777:1 on the wingloading. And uh, that's probably not to scale either since Luigi is a pretty small guy and probably isn't up in the 9^2ft range.
This means they'll have to go a hell of a lot faster than than anything we've ever seen for a landing with a canopy. How much faster? Well, that's going to depend a lot on how efficient you can actually make a wing suit, but I doubt that you can make a wingsuit as efficient as a canopy, but assuming they were the same and a heavily loaded canopy landed at say 30ish mph for level flight (landing), then you might be looking at about 80ish mph for the wing suit, but like I said, the wingsuit probably can't be made that efficiently, so you're probably looking at more like 100 mph minimum and you'll only be able to keep up that kind of speed for a very short amount of time making the timing of the landing very tricky.
Further, you can land a canopy fast because the wing continues to create lift as you transfer weight to your feet and it allows for a fairly controlled bleeding off of speed. Once you touch down in a wing suit, that's going to be it.
This is why I just don't think it can be done to the point where the skydiver walks away.
quade
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[SkyMissy 0]

It seems like I've seen pics of 70's wingsuits that looked just like flying squirrels. I would think that this would be the first design tries, as it has been so obvious in nature. Anyway, I thought those early suits had a lot of blood in their history, but that could be due to the other equipment in use at the time, too.
13,500' to the ground. We're dressed like clowns. The door's open. Hit it!

[quade 4]

Yeah, I've seen pictures of those old style suits, wrist-to-ankle type designs. Just because you can make one and fly it, doesn't mean you can land it and walk away. Those guys certainly didn't.
quade
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[cobaltdan 0]

just a side note on small flying mammals.
you can drop a mouse any distance, from 3' high or 3miles high and it will survive. i would imagine that small squirrels have similar advantage with or without wings. people do not.
as pointed out some things do not scale.
sincerely,
dan

[Zennie 0]

Just to clarify, what's really being said here is that since the gliding mammal scenario doesn't scale exactly, it cannot be applied in any form in the wingsuit context and thus does not even warrant research.
That's a pretty big leap of logic.
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[quade 4]

Quote

That's a pretty big leap of logic.

I don't think so.
What's being said is analogous to "it's impractical to make large airplanes out of paper." Sure, you could but is it really the most efficient way to go?
To some people that have experience with certain materials or principles of design, it's just not going to be the first choice right out of the box. It may make for an interesting design study, but ultimately experience has already shown that things of this nature just aren't the most efficient. Yes, you can make a human size airplane out of telephone books if you really wanted to, but it would be heavy as hell and you'd need a whopping huge engine. On the other hand, paper is almost ideal for small gliding models.
By the way, I'm all for making wing suits as efficient as possible, but right off the top of my head, I don't think a flying squirrel type design is the way to go. Among the reasons are the bio-mechanics of it -- I don't think a person is going to be able to hold the wings in an efficient position for very long. Human's just aren't built that way.
Further, as you increase the distance the wing goes down the leg, you start to get into a very dangerous design issue of the wing getting in the way of the jumpers ability to deploy. You need to make certain that when the jumper reaches back to grab the hacky, that the wing doesn't have so much slack that it covers it up. My camera suit is pretty much on the edge of this and it only goes down to about the middle of my femur. Remember that the old style bat-suits probably didn't have this as a consideration -- I'm guessing that most were a ripcord pull.
quade
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[jceman 1]

Quote

right off the top of my head, I don't think a flying squirrel type design is the way to go.

Here I have to agree with you, but not only for the reasons you have listed. A major component of the flying squirrel's equipment is a large, bushy articulated tail.
A flying squirrel uses it as a counterbalance and as a rudder to maintain stability in his glide. Even if a skydiver were to add a tail to his wingsuit for balance, he would not be able to control side to side motions; well, he might, if he had amazing sphicter control and well-developed gluteus muscles and was willing to have a butt plug inserted for each flight !

[Zennie 0]

These are the sort of specifics I was hoping to get, and they are points well taken.
I'm still not as pessimistic. Perhaps another scale to look at are ski jumpers. Without looking at the numbers, I would venture a guess that the vertical and hoizontal speeds that ski jumpers see are within the realm of possibility of what a wingsuit can (or can potentially in the future do). So if a ski jumper can survive his jump, couldn't a wingsuit flier experiencing the same vertical & horizontal fallrates do likewise?
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[quade 4]

Ok, I'm not going to do all your homework for you! But, check out a thing in ski jumping called a "k point".
quade
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[quade 4]

OK, I lied. I did some more homework. I started to get a little more curious myself and decided I needed to look at the specs of a ski jump hill.
Check it out HERE. The stuff you're interested in begins on page 29.
Ok, so, looking at this document you'll see a bit of definitions. Basically ballistics. The ideal place to land is the "K Point" That's the place where ballistically you should be so that you land with the minimum amount impact. Landing beyond the K Point gets you extra points, not just because of the distance, but also because it's WAY more difficult to land there (and walk away).
So, why not just have a Birdman land there? Well, because it's going to be REALLY freekin' difficult to judge that because the Birdman's trajectory is pretty much an unknown AND variable AND the Birdman has to land on his belly!
quade
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[quade 4]

Zennie --
I found a great photo to illustrate what I was talking about the size of the wings being an issue. Check THIS out.
I'd say that the wings on this camera flyer are, like mine, right at the hairy edge of almost being too large. Notice how the wing puffs up as the arms come in and imagine them being only a little bit bigger and how they'd really ruin your day reaching for your hackey.
quade
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[Zennie 0]

Yep. I see what you're talking about. Kinda creepy. Of course, if you're gonna land a suit, you don't need to reach for a hackey.
It would be interesting to see the evolution of wingsuits over the years. My guess is the problem you point is a primary factor in current designs.
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[mccordia 74]

>just a side note on small flying mammals.
>you can drop a mouse any distance, from 3' high or 3miles >high and it will survive. i would imagine that small squirrels >have similar advantage with or without wings. people do not.
>as pointed out some things do not scale.
I think everything scales fine (okay, maybe not 100% correct), as long as you also scale the speed at which it impact, and the forces the body of the flying critters recieve on impact.
And (as a side note) even thought they jump from tree to tree all the time, their landings are usualy pretty rough (as least that's how it looks) and they land on branches most of the time (and they bend when they land, the ground does not)
And for some silly thoughts;
I think the idea behind the wings Batman uses when he jumps of the roof in 'Batman Returns' is pretty nice (not sure if it would be workable).
They use a (retractable) metal frame, which supports the wings at the tips, and gives a much bigger surface area (which would mean more lift)
But then again...why not just add wheels, aelerons, a tail...a door and windows to a wingsuit..? It would be much more comfertable..

[drenaline 0]

Do a lot of research and simulator tests, before even thinking of trying it (remember there will be no red and silver) and try to talk to a wingsuit manufacturer to help you (they have simulators, and some research made).
About the people saying no, well remember that there were people sceptic about "jumping the silk" and look at us now. What you must do is to listen to theyr advice and take note.
Now that I think of it, would be fun to be a test pilot for that, who knows maybe a billions of dollars pay check? if its anything less then don't count on me. Me no-lika broken bones.
"Life is full of danger, so why be afraid?"
drenaline

[mccordia 74]

Just hypotheticly assuming birdsuits will one day be able to slow down anough to land safely without dying.
Everyone is assuming someone will just try and land it the first time they're trying it...
How about trying to just hit zero mph and 'land' on top of a small balloon (1 or 2 meters wide) which could be suspended at about 4500 ft or so?
After scraping the balloon the birdman could just continue freefall and deploy a normal parachute.
After 100 flawless attempts where the birdman could basicly toutch-down on the balloon (even though it would flop away immediately) it would be enough practice to try the real thing...
And if the balloon is far-fetched, you could even just try landing on a cloud (like practicing landing your chute on one) quite a few times, without the first attempt killing you in case of failure..
But I think birdman suits still have a long way to come before any of this is actualy worth thinking about :)

[quade 4]

Quote

I think everything scales fine (okay, maybe not 100% correct), as long as you also scale the speed at which it impact, and the forces the body of the flying critters recieve on impact.

The problem is things like this don't scale.
As you increase the size of the object, the ratio of volume (and weight) to surface area changes. For instance, take a cubic centimeter of water. It weighs 1 gram and has a surface area of 6 square centimeters for a ratio of 1:6.
Now make a cube 6 centimeters on a side. Now you have 216 cubic centimeters of water and 216 grams of weight, and 216 square centimeters of surface area for a ratio of 1:1.
Keep going and you'll discover that as the volume increases massively, the surface area only increases a small percentage of that.
So, the wing loading on the flying squirrel might be say .5:1, but on a human with wings appropriately sized it might more like 17:1.
Ok, I'll admit it now before somebody busts me on it. No. I haven't done the wing loading calculation for a flying squirrel!
As for impact speeds . . . they REALLY don't scale very well.
F=ma and we've already noted that the mass is going to change drastically as you scale it up.
quade
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[Zennie 0]

Ooo!! Ooo!! My turn to do research!
Southern Flying Squirrel
-----------------------------------
Length: 8 ½ - 10 inches
Weight: 1 ¾ - 3 ½ ounces
Human
----------
Length: 61 - 75 inches
Weight: 120 - 220 lbs
OK the human numbers are rough guesstimates. Me, I'm 5'8" (68 inches) & 160 lbs. Let's add 10 lbs for the wingsuit & no parachute since that's what we're gauging here. For sort of rough wingloading, let's lop off the head and assume a roughly square wing surface. So that's 56"x 56" or 21.8 square feet. That's a wingloading of about 7.8 lbs/sqft.
Now let's look at "Rocky". Let's lop off about an inch for 'da head and assume approximately a square wing surface again. That's 9" x 9" or 0.56 square feet. At .22 lbs that gives him a wingloading of .39 lbs/sqft.
So yeah, there's definitely a scalability problem here.
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[rhino 0]

Those downhill speed skiiers hit 100+ forward all the time and fall.. They live don't they? Some of the time Blue Skies .....

[StevieBoy 0]

Just a thought here.
What if you land on a moving mass, i.e. a fast flowing river, will your vertical speed be slow enough to survive your impact due to the movement of the water & I can take it that your horizontal speed will also be reduced due to the movment of the river, just a thought.
"Skydiving's a source, it'll change your life, swear to God"

[billvon 2,989]

>I think everything scales fine (okay, maybe not 100% correct), as long as you
> also scale the speed at which it impact, and the forces the body of the flying
> critters recieve on impact.

Nope. Even standing still, things don't scale. If you made a 10 foot tall ant, it wouldn't even be able to stand in 1G. Why? Because as you increase size, strength goes up by a power of 2, because a bone or muscle (for example) is increasing its strength as its cross section (width and depth) increases. However, the _weight_ of the bone is going up by a power of 3, because weight is roughly equal to volume. Enlarging an ant by a factor of 10 makes it 100 times stronger but 1000 times heavier.

-bill von

[CuriousGeorge 0]

I was talking to a very experienced wingsuit flyer this weekend who told me that he will attempt to land a wingsuit within the next year. Can't provide any more details but if it happens, I'm sure everyone will hear about it.
-g

[quade 4]

Quote

Can't provide any more details but if it happens, I'm sure everyone will hear about it.

Yeah, is Barry's fatalities page back up and running?
quade
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[AndyMan 7]

Yup, but a new URL.
http://www.skydivingfatalities.com/
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[VNugget 0]

I am not a skydiver (although I planned to take it up, before I decided to become a pilot) so I don't know if this is old news (forgive me if it is and I'm wasting everyone's time) but this video is definitely pertinent to this thread...

http://www.ehrenguard.com/clocks/mountaindive.wmv

It's a wingsuit skydiver skirting a snowy mountain ridge (it looks to be about a 30 deg. slope) at 10' AGL!

So it looks like zero sink rate wrt the ground has already been achieved, now someone has to figure out how to make contact.

[kevin922 0]

yup that would be old news :)