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Sirob

How to learn to fly wing suit - Robibird way

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If you are not able to make small adjustments (or large ones) on a BASE jump of any kind (which includes many performance wingsuit flights) you are going to be in trouble sooner or later.



O.k, I think I get what you are saying.

You are talking about the ability to make changes and I was talking about the performance flight itself.

Is this situation an example of what you are talking about?

Last year, on a jump from Smellveggan, I choose a slightly wrong angle on exit and kept going, the people standing at the exit were sure I would turn to paste.

As I was flying (looking between my legs at the wall), something did not add up and I started a carve towards the fjord and looked up...let's just say that the video would have been impressive.

A stall or panic reaction at that point would have made things really bad. Ofcourse, it was avoidable in the first place.

Kris.

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Jumping from the same altitude (more or less) over known environment from known points is beneficial for me and can give me good information if I am improving or not. Chasing something is always better than nothing, but I think clouds are not that good reference as points on the ground (if you have clear skies ground is always there).



That isn't very different from using a GPS. You're still affected by the wind, and because of that your flights are not comparable, unless the wind at your DZ is always coming from the same direction at the same velocity.

Clouds are better in that they are affected by the same wind as you are(as long as you're more or less on the same altitude with the clouds). The downside is of course that the clouds are never in the same place or at the same distance from you, and they never look the same.

Looking at the ground can give you a good idea of relative performance between different parts of the current jump, but even that can be skewed by different winds at different altitudes. And since the ground keeps getting closer(the bastard), comparing the different parts of the same jump is difficult as well.

The way I see it, unless you have a GPS with a HUD that shows you flight data corrected with very accurate real-time winds aloft data, you're just guessing. Everyone's just guessing. But I do hope that they remember to have fun while doing it...;)

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Gravity gives you initial vertical speed exceeding your sustained speed, you then transform this kinetic energy into exceedingly fast forward speed and slower fallrate, and you then bleed this extra horizontal speed into better glide and slow fallrate.



When I do a still air jump, my overall speed(velocity along the vector) is increasing until a steady state is reached. There is no increase of vertical speed ( past the sustained speed) and then bleeding of horizontal speed to gain better glide and slow fall rate. The good flights are when I can sustain this speed for the longest possible time without bleeding it using the mechanism you explained .

I don't have GPS data to support this(in part because of my stupidity and in part due to bad luck...I was very keen on collecting this information last year ) but the video certainly shows this. PM me if you want to know which one I am talking about.

Kris.

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There is no increase of vertical speed ( past the sustained speed)



Sounds physically impossible, but prove it! ;) What is your sustained speed? Suppose it's 35mph. You reach 35mph vertically in just under 2s. In 2s you won't have any significant (>10-15mph) horizontal speed. So your total speed at this time is ~40mph and the sum of lift and drag at this speed is a small portion of your weight. That means that gravity is still accelerating you down. QED. ;)
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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What you have when getting out from the plane?! Strong effect of ''whoooosh'' or what?!



From the plane, the glide "settles down" quicker, in about 20s you're in sustained flight if you exit while keeping AoA under control as to not to induce stall (i.e. you exit "puncturing the hill" to minimize the initial slowdown). Then you have full 2 minutes of sustained flight relative to clouds.

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The ''plane out'' with WS is actually stalling



I disagree. Planeout helps you to enter the low AoA mode if you don't abuse it to induce superlow fallrate. It's important to maintain AoA control after the planeout ends. Otherwise, it ends in a stall. Especially if you have to turn to LZ at that same moment.

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How about to cut 150 m of start and 150 m of opening and get rough info of glide?



If you want to eliminate the planeout effect the easy way, cut 500m (1500ft) off the start. 150m is not enough, you're including a significant portion of the planeout (which easily lasts through 1500ft) in your calculation. Better approach is to transform the glide ratio into real L/D by using acceleration correction formula.

Why would you do this? You don't have to, of course, because the GPS or map data is as real as it gets. It's all about maximizing the total distance, right?

Yes. But by analyzing L/D data (as opposed to analyzing only G.R. data, G.R. in general is not equal to L/D), you can see some interesting things. Every jump is a "sweep" through various angles of attack and thus it's like a free windtunnel experiment. You can see L/D as a function of AoA. You can see at what AoA L/D is maximum and how you can change the design of the suit to achieve the proper balance for that AoA.

What AoA do you suggest for V-2 for max L/D?
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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Yuri,
Stop looking at the WS as something like rigid plane. WS w the human body in it is not the definite flying object (I said this so many time )
What AOA I suggest?! This Q is impossible to answer. Each jumper has body weight distribution different. I suggest something easy to understand, which apply to every WS - keep the speed!!

Proportion is different. Results depends on so many factors, so that is why WS , regardless of the WS types is demanding toy to learn. Body position which is good for you will not apply to me.

Yuri as far as GR discussion goes, I will never cut the flight in to the parts. Either, jumping from the plane or cliff I am looking the whole jump because every flight has the same elements so my final interest is how far I flew.
This level of discussion is enough for this forum. more than this I rather sit and talk w you
Robert Pecnik
[email protected]
www.phoenix-fly.com

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Gravity gives you initial vertical speed exceeding your sustained speed, you then transform this kinetic energy into exceedingly fast forward speed and slower fallrate, and you then bleed this extra horizontal speed into better glide and slow fallrate.



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There is no increase of vertical speed ( past the sustained speed)



No, that is not what I was trying to say.

There is no increase of vertical speed ( past the sustained vector speed). Kinda obvious, but, in reply to the quoted part from your previous post, I was trying to say that there is no increase and decrease of the vector speed, just an increase(along a vector that is changing direction) until the forces are balanced.

Anyway, I guess we totally went off on a tangent in this thread. The idea is not to calculate L/D just to get novices used to flying for distance. The method described in this thread is a simple and practical solution.

Seriously, where do we get clouds from on every jump?
We can choose a different exit distance(spot) based on wind speed and direction.

Kris.

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There is no increase of vertical speed ( past the sustained vector speed). Kinda obvious, but, in reply to the quoted part from your previous post, I was trying to say that there is no increase and decrease of the vector speed, just an increase(along a vector that is changing direction) until the forces are balanced.



Kris, I now get what you're saying. Although these are preliminary results based on some simulations and some jumps, but needing further verification on both theoretical and experimental fronts, but here you go (time will tell if they're correct):

If your speed increases monotonically to sustained without peaking, this is a ticket to starting to fly away from the wall as quickly as possible, and it is beneficial for short flights with <1500ft of available altitude. However, for flights with >1500ft of available altitude from big shear drops where starting to fly as soon as possible is not an issue, the planeout (temporary peak of both vertical and horizontal speeds above the sustained speed and the subsequent "swoop") is beneficial for the overall distance. It is, therefore, better to dive first. Moreover, if the altitude is right (about 50-60s flight), you can extend the natural planeout for extra ~20s by continuosly slowing down as to pull right at the moment when you can't have a good glide anymore.

The best is yet to come! ;)

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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However, for flights with >1500ft of available altitude from big shear drops where starting to fly as soon as possible is not an issue, the planeout (temporary peak of both vertical and horizontal speeds above the sustained speed and the subsequent "swoop") is beneficial for the overall distance. It is, therefore, better to dive first. Moreover, if the altitude is right (about 50-60s flight), you can extend the natural planeout for extra ~20s by continuosly slowing down as to pull right at the moment when you can't have a good glide anymore.



Disagree....Please give me practical evidence
In your mathematical model it may look like this but, myy experiance shows me different.;)
Robert Pecnik
[email protected]
www.phoenix-fly.com

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In your mathematical model it may look like this but, myy experiance shows me different.



The GPS data I have looks like a zigzagy random walk (I guess the GPS got freaked out by sudden disappearance of sattelites behind the wall), so it's garbage. I have video. When I botched the exit and went headdown for a couple of seconds, I flew above the top of a nearby mountain, compared to just skimming its side on previous jumps with regular "start to fly asap" exits.

At first, I attributed this improvement to better flying because presumably with all the visual cues you fly better and better literally on each jump. We like to think that BASE makes us superhumans being able to process all those visuals cues and adjust our body position in microseconds just the right way for superhuman glide that is not achievable on a skydive. ;) It's after I wrote wingsuit equations and played with some calculations I realized that it's a wishful thinking and that ignoring the importance of dynamics on a WS BASE jump can lead to wrong conclusions.

I am not talking about an intentionally prolonged headdown dive, but rather the more "natural" dive where your AoA remains low (about the same as for best L/D), e.g. 8-10 degrees, and you adjust you pitch angle continuously from rather headlow to normal sustained flight. Then you'll fly overall farther than with the 45-degree exit which is best to start flying quickly, but dissipates too much of the initial energy.

This might be wrong, but even wrong result is a valuable learning experience. I find fooling myself is a lot of fun. ;)
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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Then you'll fly overall farther than with the 45-degree exit which is best to start flying quickly, but dissipates too much of the initial energy.

This might be wrong, but even wrong result is a valuable learning experience. I find fooling myself is a lot of fun.



45-degree exit is not good exit. often end head low. Best is to jump flat... Regarding the position during the flight, you are correct. Head low , pitch angle low.. That is the formula. Short way of description would be - keep the speed, regardless you might feel is not right. Speed will provide lift , lift will provide altitude :)
Robert Pecnik
[email protected]
www.phoenix-fly.com

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Yuri,

Jumping flat seems to put the initial AoA at Zero or close to it. As the downward speed increases, it initially increases the AoA, if we reduce pitch we are maintaining a low AoA. Sounds complicated to do but it is very natural if we just fly based on the feedback from the air.

I don't see how 45 degrees is relevent at all. If we launch down at a 45 degree angle the AoA is also zero but mastering that exit is really hard.

Kris.

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However, for flights with >1500ft of available altitude from big shear drops where starting to fly as soon as possible is not an issue, the planeout (temporary peak of both vertical and horizontal speeds above the sustained speed and the subsequent "swoop") is beneficial for the overall distance. It is, therefore, better to dive first. Moreover, if the altitude is right (about 50-60s flight), you can extend the natural planeout for extra ~20s by continuosly slowing down as to pull right at the moment when you can't have a good glide anymore.

Yuri



You are not the only one to think this.

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As you gain speed you can flatten the track in the last few seconds before pull by looking flatter out towards the horizon. This is only applicable when you have reached max track speed. This is much like a canopy flaring, you trade speed for lift momentarily.



Here is an article by Lukas Knutsson(RIP). 'Tracker.mov' is available for download on skydivingmovies.com.


Memorial video watch him track at 2:36.

These are Lukas's thoughts(quoted in Tom's post) on flying in the days when jumping from cliffs(in a wingsuit) was just a few years old.

Kris.

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