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nathaniel

effects of height and mass

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Picking this up out of Medusa's thread so as not to confuse his butt buddy

Tonto wrote:
Quote

Originally posted by Tonto:
Of course, the lighter you are, the easier it is to fly, to the extent that bits of dirt (dust) are easy to see suspended in a sunbeam longer than you or I or any wingsuit pilot can fly, with no aerodynamics or skill what so ever.


Aha, but dust does not rely on airfoils creating lift to say up. Dust floats due to its size and mass vs the viscosity and density of air, and the strength of air currents in the environments we live in.

Quote

Originally posted by Tonto:

Q. How many biological flying creatures are there that weigh 160lbs?
A. Zero



Humans don't fly quite like a bird, we glide like a flying snake or a squirrel. Birds use their muscles to flap their wings, expending energy to generate power. They are limited by their mass because they're not particularly strong.

We humans convert the chemical energy in the plane's fuel to potential energy in our bodies, and then let gravity do the work of creating lift. We're energy leeches, our ability to ride up in the plane is not affected by our mass unless we get too fat to skydive.
My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

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So... how many 160lb flying snakes, or squirrils are there?

A. Zero

It's easier to get smaller things to fly than bigger things. You can argue that as much as you like, but I think we all know it to be true.

There are millions and millions of flying creatures that weigh under 1lb, and none - not one - that weighs over 45. Argue all you like. It won't change that.

As for birds not being "particularly strong" well, I guess it depends on how you define strength. They can't bench press much, but then no Olympic weight lifter has flown across the channel under their own power. They seem strong enough to fly unaided, and I'm not strong enough to do that, so I think they're stronger than I am.

t
It's the year of the Pig.

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Quetzalcoatlus had a wingspan of 12 metres (40 feet) but weighed only 50 kilograms (110 pounds), and lived during the late Cretaceous period.

http://en.wikipedia.org/wiki/Pterodactyl

We had beter all go on diet or we may become extinct too


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If you don't have wings you will never fly

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So... how many 160lb flying snakes, or squirrils are there?

A. Zero



You are still, comparing apples and oranges.

A 160lb flying snake might be really good at flying, but perhaps lousy at protecting itself against predators so it will be dead before it is able to make baby snakes...

A naturally flying/gliding creature has to balance lots of factors, not just the optimal flight performance to be a success. It has to be safe against predators, parasites, etc. It has to have a form that allows it to gather food and consume it and thus gain energy faster than it uses it up and so on. There are a lot of factors.

With cheap oil and slaves, we rich humans do not have many of those limitations...

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Hi

My take is as follows

6'6 = 2.01m
160lb = 72.57kg

72.57kg/2.01m = 36.10 kg per meter

now

5'0 = 1.5m

so

x /1.5m = 36.10kg per meter

X = 54.15 kg = 119.27lb

so to compare apples with apples

Give two people the same suit with same experience.
The one being 6'6 160lb and the other being 5'0 119.27lb. Now you have two people with same pounds per inch of length. Lets see who flies further and faster.


I think 5.0 at 119 pounds will kick ass
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I like comparing apples and oranges.

Since each person who climbs into a wingsuit is different in height, weight, body structure, age, fitness, experience, desire, imagination etc - we will ALWAYS be comparing apples and oranges. I just think that from what I have seen, small and light whips tall and thin every time, with the possible exception of flat out forward speed.

t
It's the year of the Pig.

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I just think that from what I have seen, small and light whips tall and thin every time, with the possible exception of flat out forward speed.

t



That might very well be true, but statements about the existence of animals with certain properties do not give any support for that argument, because the animals will have to do more than just archive a good glide.

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I just think that from what I have seen, small and light whips tall and thin every time, with the possible exception of flat out forward speed.

t



That may be true.

If we are talking about wingloading. The shorter lighter(in our example 6'6", 160 vs 5'4" 100 lb) person has a lower wingloading.

The lighter person wins in a floating race(until strength becomes an issue) no doubts there. When it comes to glide, I can only comment if both people are built the same...then the lighter person has an advantage(having been both people myself...90kg vs 73 kg).

Kris.

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Now you have two people with same pounds per inch of length.



Lift varies with width in addition to length. Humans tend to have arms approx as wide as we are tall, esp if you wear one of tonysuits' latest bedsheets, so I think it makes sense to take the height squared.
My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

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Since this thread was opened with my being quoted, and with animals involved - I'll state whatever I feel like, thanks.;)

You may feel that the industrial revolution and 100 years of mechanised flight opts us out of the food chain, but I disagree. We cannot escape our evolution.

t
It's the year of the Pig.

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You may feel that the industrial revolution and 100 years of mechanised flight opts us out of the food chain, but I disagree. We cannot escape our evolution.

t



That sounds like the same argument the wright brothers heard over and over before proving everybody wrong :)
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but then no Olympic weight lifter has flown across the channel under their own power.



you may find this interesting

not unaided, but human powered flight, none the less


as for the height and mass debate in wingsuit skydiving, maybe the tall and light people who feel they have the advantage should take the 'T-challenge'

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Sam, I thought you'd know me well enough to know that I would not have used the Channel example if I never knew of that flight. He was a cyclist - not a weight lifter. This forum is just like any other. People beleive what they beleive, and resent others who do the same thing.

Everyone who is "Tall and light" seems to want to beleive that they are genetically predisposed to being a better wingsuit pilot. That's not what I've seen in my experience. Edgar is tall and thin. You're kinda there, in a chunky way. Jules is certainly there, as is Timoty. All you guys fly a lot, and your peers have respect for your ability and experience. Gavin and Rainer have maybe 100 wingsuit dives between them, and fly an S1 and Classic respectively. They are not current or very experienced. They are both around 1.6 something though, and around 60 kg, and the numbers they post on those suits are numbers anyone in a modern suit would envy. There must be a reason for that. It can't be their experience. It can't be their currency. It can't be their modern gear. It must be something else. What do you think it is?

t
It's the year of the Pig.

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as for the height and mass debate in wingsuit skydiving, maybe the tall and light people who feel they have the advantage should take the 'T-challenge'



I will at the first opportunity. Just so there is no confusion. If this challenge involves flying for time. I know I have already lost. I fancy my chances if it is glide.

Kris.

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I was pretty sure you knew of that flight, it was more for the benefit of those young punks out there who did not know.

to be clear, I think we probably believe the same thing about this topic

I have no want to believe that being tall and light predisposes one to being a better wingsuit pilot.

If I am indeed in that category (not too chunky?? -thanks for that one buddy) then wouldn't it be cooler if I wasn't genetically advantaged in wingsuit flight, yet still manage to fly reasonably OK?

As for the shorter people's reasons for success, I don't know, maybe it has to do with a better length to width ratio, or better weight distribution, or bigger surface to volume ratio?

I think we need to run some lab tests on them...

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From what Tonto has posted I believe he is talking about time.

That is pretty straightforward.

m*g = K * V* V

for most of the flight. Or velocity is proportional to the squareroot of weight.

Can we say without doubt that the shorter lighter people always fly longer than the taller people of equal weight?

I don't know about predisposition but I believe that being lean and tall is an advantage. Is it more of an advantage than being short and light? I don't know the answer to that.

Anyway flying for glide to me is about getting the best that my physical shape and strength will allow. And changing that to what I think is advantageous as much as I can in the gym.

Kris.

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They are both around 1.6 something though, and around 60 kg, and the numbers they post on those suits are numbers anyone in a modern suit would envy. There must be a reason for that. It can't be their experience. It can't be their currency. It can't be their modern gear. It must be something else. What do you think it is?

do they circle in the thermals ? :D
scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

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the numbers they post on those suits are numbers anyone in a modern suit would envy. There must be a reason for that. It can't be their experience. It can't be their currency. It can't be their modern gear. It must be something else. What do you think it is?

t



I don't know the gentlemen in question but could it be that they are lieing through their teeth? Hey, they are not BMIs by any chance,.... are they?B|

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So... how many 160lb flying snakes, or squirrils are there?

A. Zero

It's easier to get smaller things to fly than bigger things. You can argue that as much as you like, but I think we all know it to be true.

There are millions and millions of flying creatures that weigh under 1lb, and none - not one - that weighs over 45. Argue all you like. It won't change that.

As for birds not being "particularly strong" well, I guess it depends on how you define strength. They can't bench press much, but then no Olympic weight lifter has flown across the channel under their own power. They seem strong enough to fly unaided, and I'm not strong enough to do that, so I think they're stronger than I am.

t



"The heaviest flying bird is the great bustard which weighs up to 46 pounds (20.9 kg). "

The biological problems are many: wing area goes up as the square of linear dimensions, but mass as the cube. Bending moments increase with mass, but non linearly with wingspan. Muscle strength requirements also scale non linearly, and so muscle mass requirements also work against large size. Swans are the commonest "heavy" bird (male Mute Swans can reach 30 pounds). Anyone ever watch swans taking off and landing?
...

The only sure way to survive a canopy collision is not to have one.

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