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msmithd8769

Wingsuit Glide Ratio

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Would like to get some info on what an average glide ratio should be in a wingsuit. I realize it is dependent upon some variables such as suit type and how effective your body position is but I am figuring that a 2:1 glide ratio should be a good average. Would you folks agree with that? I know I have covered really good distances on some of my jumps but want to get some other input.

I fly a BirdMan GTi.

Thanks....
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"And when the prophet shall arise who appeareth as a bird then the time of the Lord draweth nigh and the flock shall rule the earth."

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i think you would be doing pretty well to get 2:1 in a GTi without a helping hand from upper winds. i'd guestimate an average GR from an average pilot to be closer to 1.6:1

the really good guys in the advanced suits talk about 2.5:1 to 3:1, without the help of winds.

good trackers can exceed 1:1 without a wingsuit.

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glide ratio has nothing to do with winds. It is measured/calculated in zero wind.



agreed.
poor wording on my part.

i wasn't clear in what i was getting at, i was referring to the fact that when people use a GPS on a skydive to measure the distance traveled horizontally V vertically these figures include the effects of wind. and as such DO NOT represent a true GR. as the winds vary in direction and strength at different heights i'd guess it's pretty hard to work out the true GR in this manner.

i guess the guys that have done the tunnel testing have some reliable figures! ;)

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> I was referring to the fact that when people use a GPS on a skydive to measure the distance traveled horizontally V vertically these figures include the effects of wind....
Well. Let's define:
course 1: X°
course 2: X° ± 180°
Now I state as follows:
If you do a wingsuit skydive where 50% of time you fly along course 1 and remaining 50% of time you fly along course 2, when you download the GPS track and do the average glide ratio, the effect of wind is zero (OK, please don't talk me about different wind speeds at different heights...).
Just my 0.02€
Stay safe out there
Blue Skies and Soft Walls
BASE #689 - base_689AT_NO_123_SPAMyahoo.com

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If you do a wingsuit skydive where 50% of time you fly along course 1 and remaining 50% of time you fly along course 2, when you download the GPS track and do the average glide ratio, the effect of wind is zero (OK, please don't talk me about different wind speeds at different heights...).
Just my 0.02€



Not exactly. If there is any crosswind component, it will increase the total distance you have flown. If you measure the distance by GPS without plotting it over the map, the numbers will be inflated.

If you try to stay over a specific line in a crosswind, you will have to crab - which will decrease your distance flown over the ground (and measured by GPS).

There is just no practical and reliable way to measure L/D precisely on a skydive.

bsbd!

Yuri.

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There is just no practical and reliable way to measure L/D precisely on a skydive.



There would be if I could afford to put it in production. At this point it's just a design for a cool gadget that will measure L/D independently of ground speed, so wind speeds do not matter, and no special patterns need to be flown.

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> ...If there is any crosswind component, it will increase the total distance you have flown. If you measure the distance by GPS without plotting it over the map, the numbers will be inflated.
Yes. I agree. I know that doing course 1 and course 2 will average only the front wind component, while the cross component cannot be compensated. But you still get a reasonable number. And indeed it will be "sort of copmpensated" in different skydives in different days.

> There is just no practical and reliable way to measure L/D precisely on a skydive.
I agree. But here we are NOT trying to send rockets to the moon, we are trying to figure out a reasonable way to get a reasonable glide ratio out of our wingsuit flights. And see if we are improving or not.
In the end, we are talking about a "disturb", which is the cross component of the wind, and the wind itself is in the range of 20-30-40-50 km/h, and the wingsuit flight has got a horizontal component of 140-160-180 km/h. The disturb is in the range of 1/5 of the horizontal speed.
Stay safe out there
Blue Skies and Soft Walls
BASE #689 - base_689AT_NO_123_SPAMyahoo.com

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There is just no practical and reliable way to measure L/D precisely on a skydive.



The device that measures true L/D precisely (and independent of wind speed) can be built.

In the simpliest, mechanical form it would consist of a plumb and a weathervane. The angle between plumb's vertical and weathervane's relative wind direction is equal to 90 minus true L/D angle.

In electronic form, it would consist of an electronic level indicator and an electronic wind direction indicator. The difference between two signals can be transformed into sound with the pitch proportional to L/D (similar to variometers). The device has to be mounted on a foot-long (or so) pole to be in the 'clean' air.

Any wizes out there to build such a device? ;)

Yuri
Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

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Typically known glide ratios for canopies are in full-flight, not in the many other flight modes available that are likely to be employed when docking.

and even so, when docking on a canopy the WS is in deep brakes anyway, so that's not a good measure.
"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

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and even so, when docking on a canopy the WS is in deep brakes anyway, so that's not a good measure.



I’d like to know where you are getting the information you based that statement on.

In my very limited wingsuit-canopy-relative-work experience that is not true.

I’m not talking 21 square foot canopy either, I’m talking 40 square foot canopy with no weights.

My two jump-tickets’ worth..

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What is the glide ratio of Luigi's Icarus too tiny canopy?



Same problems getting an accurate L/D measurement with canopies as with wingsuits.



True!

Regarding this particular project, i estimate max L/D during the dock peaked around 2.0 or just under.

bsbd!

Yuri.

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horizontal speed of WS in best-glide flight is in the triple digits, and I'm gonna go out on a weak limb and say that's much more than the canopy's forward speed. Perhaps I'm underestimating the forward speed of this 40 sqft canopy? ;)
"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

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I never said all pilots will have the same speed, only that a canopy will not keep up with a WS in full flight, therefore the WS puts the brakes on. If you disagree then please show me a canopy docking on a V1 in full flight and my hat will be sincerely off to you and I will stand corrected. It's clear in the Canadian WS-canopy dock the WS had the brakes on. It's really not rocket science.
"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

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I don't disagree with you that I had to slow the forward speed a bit (brakes on) to match the 40,

but I do disagree that it was 'deep brakes'

I normally have to slow my forward speed down way more in the average flock than I had to with the 40

brakes, yes. deep brakes? not even close

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I don't disagree with you that I had to slow the forward speed a bit (brakes on) to match the 40,

but I do disagree that it was 'deep brakes'

I normally have to slow my forward speed down way more in the average flock than I had to with the 40

brakes, yes. deep brakes? not even close



So my description didn't match your specific and particular experience perfectly to a t (everybody's different). Naturally how much brakes you apply will depend on your WL and other factors, and I'm not gonna argue over semantics cause I don't want to feel like I'm running in the Special Olympics, as they say. Getting back to the point I was trying to make, I feel a suit flying in brakes next to a canopy doesnt give a good approximation of it's maximum glide capabilities.
"The evil of the world is made possible by nothing but the sanction you give it. " -John Galt from Atlas Shrugged, 1957

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