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KrisFlyZ

Tracking : True or false?

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Do you really think that golden nights track 1:1 with only booties on their legs???

I think that even 0.6:1 is realllyyyy gooood!



You don't use booties when doing a diamond track.

I tend to agree with the 1:1 for a GOOD tracker. (Not everyone has the skill, or the body to pull that good of a track).
"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

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Talk to manufacturers of high performance canopies that also really understand wingsuits, and they'll tell you that you get a better glide from a wingsuit than a small canopy. This is something I've witnessed on many occassions, as well.


Please, everyone, do not jump to conclusions about this statement. While true, please remember that to achieve these wonderful glide ratios, wing suits REQUIRE faster air speeds. So, don't go thinking you can try to land that wing suit today. It might be coming, but we've got to find someone who can run really, really fast.

And with that, I'll shut up and go do some more jumps so that I can begin thinking about trying wing suit flight.

TTFN,

topher


"...there is a there out there..." - Tom Robbins

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So, don't go thinking you can try to land that wing suit today. It might be coming, but we've got to find someone who can run really, really fast.

Or invent retractable Landing Gear;) A Micro Robotics engineer might be able to come up with something:P

MAKE EVERY DAY COUNT
Life is Short and we never know how long we are going to have. We must live life to the fullest EVERY DAY. Everything we do should have a greater purpose.

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Glide ratio is determined by the lift/drag ratio, not the surface area.

Descent rate depends strongly on surface area.

I think you have confused the two concepts.



Yes i know that. it's just that in most cases the lighter the wingloading the better the glide ratio is (Sail planes, paragliders,... spaceshuttle)
I know glide ratio depends on how much lift/air resistance the wing produces. but it also depends on the wingloading surface/weight... that's why i mentioned surface. it just entered my mind first. i know it's a lot more than just surface...



You just contradicted yourself.
...

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

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You just contradicted yourself.



I may be stupid, but i can't find where i contradicted myself. Ok whoever thinks i'm wrong, so be it.
If you want to teach me something PM me...

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You would do well to read up on aerodynamics. A good place to start might be http://www.av8n.com/how/.



already read that. it's a great book. thanks for the link.
"George just lucky i guess!"

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I think hooknswoop is right. If you want to know how you track, then you can use a ProTrack or Neptune to measure your fall-rate. If you know your average belly fall rate, and you measure your slowest descent rate in a track, then using iterative trig, you should be able to see how much verticle speed you traded for horizontal speed. With that, you can determine the glide ratio.
Trapped on the surface of a sphere. XKCD

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You just contradicted yourself.



I may be stupid, but i can't find where i contradicted myself. Ok whoever thinks i'm wrong, so be it.
If you want to teach me something PM me...

.



I wrote:
"Glide ratio is determined by the lift/drag ratio, not the surface area.
"
You wrote:
" Yes I know that"


followed almost immediately by:

"I know glide ratio depends on how much lift/air resistance the wing produces but it also depends on the wingloading surface/weight"

which contradicts your first statement that you know it doesn't depend on surface area. QED
...

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

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ok, ok it's no point in arguing whether i contradicted myself or not. it won't solve anything.

I shouldn't say "Yes i know that" i should say (or ment to say) "yes that is partly true, it depends on all lift/drag and surface area/weight"

ok now?

Now please don't reply again this is not true if you think it's not. I won't get killed if i'm wrong about this specific thing. If you really want to discuss this PM me.

back to glide ratio

You could also use a GPS in combination with altimeter. than you'd really see the glide ratio. but it should be measured in no wind. And as far as i know robi already did this a couple of times with his wingsuit...
Same should be done for any type of flying to be sure about glide ratios. till then we can only argue who is right and who is wrong.
"George just lucky i guess!"

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ok, ok it's no point in arguing whether i contradicted myself or not. it won't solve anything.

I shouldn't say "Yes i know that" i should say (or ment to say) "yes that is partly true, it depends on all lift/drag and surface area/weight"

ok now?

.



No. You're still wrong. See this post:

www.dropzone.com/cgi-bin/forum/gforum.cgi?post=1079445#1079445
...

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

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Yes i could be wrong. But i'll believe you all are right when i see some numbers and calculations in formulas for canopy flight not before. And there is a "slight" difference in planes and canopies...
I just don't buy it just because some experienced guy and a great physics or a pilot sais it's so. Prove it with calculations and i'll gladly believe it. ;)

Few more replies that i'm wrong and i'll really dig into this stuff and calculate if myself, to see whether i'm right or wrong! :S
"George just lucky i guess!"

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Few more replies that i'm wrong and i'll really dig into this stuff and calculate if myself, to see whether i'm right or wrong!



OK. You are wrong.:|
-Josh
If you have time to panic, you have time to do something more productive. -Me*
*Ron has accused me of plagiarizing this quote. He attributes it to Douglas Adams.

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Few more replies that i'm wrong and i'll really dig into this stuff and calculate if myself, to see whether i'm right or wrong!



OK. You are wrong.:|
-Josh



Chalk up a vote from me too. You are wrong
www.WingsuitPhotos.com

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Post: Jump run was 1/2 mile west of the DZ and into the wind (South), I opened 2 miles to the East of the DZ. I drove the road from where I opened to the edge of the DZ and added 1/2 mile. The pilot used GPS to fly jumprun 1/2 mile to the West and maintain a straight jumprun to keep the competion fair (it was a whole otter load). Pro-Track for exit, opening altitudes and free-fall speeds.

I looked it up on Jump-Track
Exit:13,500
Deploy:2,100
Free-fall time: 102 sec
By my math that equals 76 mph avg speed and a 1.158:1 Glide ratio



Yep.. I was on that jump. That shit was bad ass...

Won the tracking contest then bought the whole DZ Corona.. First Class,,,,B|

Rhino

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Yes i could be wrong. But i'll believe you all are right when i see some numbers and calculations in formulas for canopy flight not before. And there is a "slight" difference in planes and canopies...
I just don't buy it just because some experienced guy and a great physics or a pilot sais it's so. Prove it with calculations and i'll gladly believe it. ;)

Few more replies that i'm wrong and i'll really dig into this stuff and calculate if myself, to see whether i'm right or wrong! :S



OK, here's the formula:

Glide ratio = Cl/Cd

where Cl = lift coefficient, Cd = drag coefficient.

Satisfied?
...

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

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I know that in theory glide ratio is independent of wingloading.

However, I've also observed that skinny people, or people with long frames, tend to get better glide ratio on their wingsuits. This means that my observations tend to contradict the physics of the situation, which makes me think something else is going on here.

Can anyone explain why this might be happening?
-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

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I know that in theory glide ratio is independent of wingloading.

However, I've also observed that skinny people, or people with long frames, tend to get better glide ratio on their wingsuits. This means that my observations tend to contradict the physics of the situation, which makes me think something else is going on here.

Can anyone explain why this might be happening?



Skinny describes shape and shape affects airflow and airflow affects Cl and Cd.
...

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

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I know that in theory glide ratio is independent of wingloading.

However, I've also observed that skinny people, or people with long frames, tend to get better glide ratio on their wingsuits. This means that my observations tend to contradict the physics of the situation, which makes me think something else is going on here.

Can anyone explain why this might be happening?



The wingsuit that fits the tall, skinny guy is not the same airfoil as the one that fits the short, fat guy.

You have to compare Walt apples to Walt apples.

-Josh
If you have time to panic, you have time to do something more productive. -Me*
*Ron has accused me of plagiarizing this quote. He attributes it to Douglas Adams.

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For anyone that's interested, take a look at:

http://www.flywight.co.uk/flight.pdf

(it's on the Isle of Wight Hang Gliding and Paragliding Club website)

It gives a good basis for flight theory, more from the perspective of paraglider pilots but is still relevant to skydiving canopies. Section 5 on page 11 gives an explanation of glide angle.

I would guess that tall/skinny people are better able to de-arch, effectively reducing the undersurface of the "wing" relative to the top surface, generating more lift. :)
--
BASE #1182
Muff #3573
PFI #52; UK WSI #13

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In this case, I don't think it's a drag issue: I would have thought that should increase with a "taller" person, in the same way drag increases with a lower aspect ratio.



Hmm. Interesting. That might explain why some short skinny people (Petter comes immediately to mind) are such phenomenal wingsuit pilots.

There's obviously a lot more going on here than just wingloading. I guess it's time to start watching what I eat and exercising.
-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

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Tom Skip the diet and exercise....just buy a bigger wingsuit.



Holy Resurrection, Batman!
Every fight is a food fight if you're a cannibal

Goodness is something to be chosen. When a man cannot choose, he ceases to be a man. - Anthony Burgess

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Tom Skip the diet and exercise....just buy a bigger wingsuit.



Holy Resurrection, Batman!



Yep. I was reading this thinking it was a current thread, until I got to the post where someone was talking about landing a wingsuit by running really, really fast! :D

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1:1 is consistent with what I've seen of the Golden Knights tracking demonstrations. IIRC it is called a "diamond track," and results in two smoke trails crossing at about a right angle, which indicates 1:1 in an established track for both jumpers.



Calibrated eyeballs?
Chuck Akers
D-10855
Houston, TX

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