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StarFlyer

Glideslope in a track

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After breakoff, turning away, and initiating your track, does anyone know what the glideslope a typical belly-fly track might be? (For example, how many feet horizontally can you move for each 100 feet vertically?)

Two variables that affect tracking rates I expect will be 1) experience (how good you do it), and 2) clothes you're wearing (e.g. RW suit with booties versus shorts and tennies).

I'm trying to get some ballpark ranges for what horizontal distances to expect in a track. Thanks! Jack

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StarFlyer

After breakoff, turning away, and initiating your track, does anyone know what the glideslope a typical belly-fly track might be? (For example, how many feet horizontally can you move for each 100 feet vertically?)

Two variables that affect tracking rates I expect will be 1) experience (how good you do it), and 2) clothes you're wearing (e.g. RW suit with booties versus shorts and tennies).

I'm trying to get some ballpark ranges for what horizontal distances to expect in a track. Thanks! Jack



Best can achieve a little over 1:1 in a RW suit. Typical is probably more like 0.7.

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

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radical_flyer

***Best can achieve a little over 1:1 in a RW suit. Typical is probably more like 0.7.


With booties? Also do you get a better glide ratio in a tracking suit?

Yes and no, if you lack the skills tracking suit will probaply result in even worse glide ratio... Good tracker with a tracking suit can reach 1.5 glide ratio, with one piece maybe even high as 2.0

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Third variable: Angle. I've definitely seen people with really fast tracks point their body towards the earth at a 30-45 degree angle. That's definitely going to affect their distance over the ground.

Booties only help if they're used properly, body position matters much more. Ever been on a tracking dive where people in freefly suits out track the bootie suits? It's common.

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StarFlyer

After breakoff, turning away, and initiating your track, does anyone know what the glideslope a typical belly-fly track might be? (For example, how many feet horizontally can you move for each 100 feet vertically?)

Two variables that affect tracking rates I expect will be 1) experience (how good you do it), and 2) clothes you're wearing (e.g. RW suit with booties versus shorts and tennies).

I'm trying to get some ballpark ranges for what horizontal distances to expect in a track. Thanks! Jack



Even highly experienced jumpers might have a hard time correctly answering this question. There are a lot of variables and upper level winds play a big role if you are trying to measure against the ground.

Look at this file. I did this when I had about 70-90 jumps as I recall.
http://pyrodan.privatedata.com/skydive/tracking/tracking-data-sept-22.pdf

There are some basic physics that can’t be overlooked.

1. You will only gain speed based on the lateral force exerted on your total mass….meaning, it takes time to get up to speed.
2. The lateral force depends on body shape, flying style, and other things but does not exclude body angle against the air. In one form or fashion you always trade altitude to apply the lateral force that builds your horz speed. You can’t get something (speed) for nothing. Getting speed cost altitude no matter how you slice it.
Instructor quote, “What's weird is that you're older than my dad!”

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sammielu

Booties only help if they're used properly, body position matters much more. Ever been on a tracking dive where people in freefly suits out track the bootie suits?



seems to be a pointless comment - it's not like those are mutually exclusive


(IMO - I don't see that very often. What I do see is the most experienced trackers do better than the newbies regardless of suits, (which I think is the good point you are making)

But out of the most experienced tracker groups - the bootie flyers beat the others by a LOT)

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

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kallend

*** Ever been on a tracking dive where people in freefly suits out track the bootie suits? It's common.



No. Just the opposite, in fact.

(not in direct reply)
Almost 100% of my jumps are in a wingsuit but I do like to study tracking. 5Mar16 I joined some friends on a tracking dive. I was very rusty and was asked to lead. The DZ is 1200 above sea level so from a C182 we normally jump from 9,500 AGL. I jumped wearing a short sleeve Tee-shirt, jeans, and sneakers.

I was worried about sinking too much so I tried to track hard. It did feel to me like the lack of booties hampered my horz performance. My ground speed was much less than I have seen in the past but I am not sure about what the upper winds were doing. From what I was told we were at about 45 degrees, heading into a wind from the NE. There was a 90 degree turn in the flight and the data does not support a 45 degree headwind from the NE.

What was most evident is that I suck at leading. My friends sunk out and I just kept on trucking.

Average vertical speed after turning north was 97 MPH (happy with that). The horz speed was 42, which is pretty slow by my experience.....with booties.

The attached KML file can be viewed with Google Earth.

[inline track-data.JPG]
Instructor quote, “What's weird is that you're older than my dad!”

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dthames


I was worried about sinking too much so I tried to track hard.



And right there we have the secret.

Far too many people are lazy about tracking.
...

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

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sammielu

Third variable: Angle. I've definitely seen people with really fast tracks point their body towards the earth at a 30-45 degree angle. That's definitely going to affect their distance over the ground.

Every flying or gliding machine, even the tracking human body, has a particular speed and angle of attack that will be the deliver the best lift-to-drag ratio. When first starting out, your angle to the horizon will be fairly steep, since the relative wind is coming from straight below. As you pick up speed in your track, the relative wind will be coming more and more from in front. To maintain the more efficient AOA, you'll have to flatten out some relative to the horizon.

When you say fast, do you mean vertically or horizontally?
My goal is not necessarily speed, but the most horizontal for a given vertical, in other words, the best lift-to-drag ratio.

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