Performance Flying - article to download

[unclecharlie95 3]

Robert Pecnik, Scott Bland, Perry Trowbridge and myself have written a document about "Performance Flying".

If you are interested in some tips to increase your flight performance in terms of distance or freefall delay go check it out.

http://www.phoenix-fly.com/articles.htm > Performance Flying


Long flights,

James

BASEstore.it

[speedformula 0]

Dang, thats what I call dedication.
thanks for takin the time.
ps, when does the video came out ?

best regs
paul

Keeping it real 22x7

[mccordia 73]

Great article...feels good to read a bit more in depth on what is usualy covered in between the lines in the over 21.000 posts already on this wingsuit forum :)

I only recently started to 'fly' more, and was quite often doing the floaty thing (as I think a lot of people are, especialy in the beginning...often slowing down almost up untill your stall-pointThat floaty flying was often a problem when trying to catch up with someone flying really fast (especialy because I'm usualy also looking up/ahead)

About max distance flying>
How does the 'dont strech your wings completely to not collapse the cells inside wings' fair when going for maximum distance in suits with hard mylar inserts in the wings?

Because in those you can stretch the wings as big/wide as possible, and they will still have the perfect profile (and wont collapse?)
like V1 (dont remember if it had multiple ribs there or only 1 per wing) and S3S?

Or is the arc in the wing (from body to hand/finger-tip and between legs) also needed for lift? Or does a flat cross-section (like an airplane wing) work best?
Something that had me wondering (see 1. or 2. image)

JC
FlyLikeBrick
I'm an Athlete?

[unclecharlie95 3]

good question, that Croatian guy beat me to it, see below

btw my mac had a fit opening the bmp, can you post a friendly jpeg??
(thank you glamour baby)

BASEstore.it

[dragon2 0]

LOL very artistic

I'm a floater too, and the camera makes it worse. As demonstrated by the mucho photo's from the last birdman weekend, with me looking up at a nice formation getting higher and higher and futher and ...

ciel bleu,
Saskia

[gus 1]

Nice doc J, I'm a recent convert to the head low position and it rocks!

Gus

ps Have attached bmp converted to jpg

OutpatientsOnline.com

[skreamer 1]

That article seems lacking - no windtunnel research was done.

As someone who has covered a lot of distance (vertically) and made many two minute flights (five in total) in a wind tunnel I hereby offer my services.

Have your people call mine.

Will
il corniglio bianco (grande)

PS I've never actually flown a wingsuit, but who cares - I've been in a wind tunnel.

[mccordia 73]

Quote

Nice doc J, I'm a recent convert to the head low position and it rocks!

Yea..I actualy wrote about that a week ago...
I only just started going more head-low last week, and managed to cover way more ground and feel way more speed (and somehow also went much, much slower down then normal..probably due to increased lift from the speed?)

Went from 45 to 47 mph fallrates into 40 mph and even 35 mph fallrates...
I think this is especialy advice to take to heart for people who potato-chip constantly...who try to fly it way to much head-high (at least thats what I did in the beginning)

JC
FlyLikeBrick
I'm an Athlete?

[KrisFlyZ 0]

The V1 has one mylar rib in the arm wings. The one closest to the fingers.

Just want to make an observation.

If you wear glasses, the natural instinct will be to look thru the center of the lens and it is extra hard to keep the chin to chest if you are looking where you are going.


Kris.

[robibird 2]

*****************************************
About max distance flying

How does the 'dont strech your wings completely to not collapse the cells inside wings' fair when going for maximum distance in suits with hard mylar inserts in the wings?
******************************************

Regardless of Mylar ribs the wings should not be stretched.

Two reasons why:

1. The inflatable wing is a ‘’live’’ object and since the leading edge ( most critical part on every wing in terms of generating lift ) is not a perfect shape, the WS pilots primary job is to allow wing to form by it self ( using pressure ). The only way to do that is to relax the center and trailing edge of the wing.

2. Every wing (even on the most simple wingsuits) has a so called angle of incidence (angle between ws pilots longitudinal axis and the wing chord in the wing root. If you stretch the wing fully, without feeling the result you will end up flying inefficiently.

******************************************
Because in those you can stretch the wings as big/wide as possible, and they will still have the perfect profile (and wont collapse?)

like V1 (dont remember if it had multiple ribs there or only 1 per wing) and S3S?
****************************************

Mylar ribs are not made to keep a perfect profile since they are only attached to part of the profile NOT the full length. It is only about 2/3 of the profile. (check out the V1 leg wing or S3S arm or leg ribs)

Try to completely stretch the wing and you’ll see that mylar ribs will also distort as well. This is the most common misconception about mylar ribs.

The Mylar does not help wing to start flying sooner nor does it make a significant difference to the wing performance (for flying slow or for distance)

If your body position is bad or wrong the mylar could even work against you!

Infact the primary reason for mylar on the WS is simply to reduce small vibrations of the trailing edge.

Robert Pecnik
[email protected]
www.phoenix-fly.com

[nicknitro71 0]

Robi,

The wing grippers allow to "stretch" the wings more...are you suggesting that it's better to fly "empty-handed" or to keep tention on the grips and bend at the elbow more?

Thanks

Memento Audere Semper

903

[unclecharlie95 3]

Robi asked me to post the reply:

The advanced suits like V1 have grippers to extend the surface and ( w proper use) increase efficiency of the WS.

On V1 the ''sticks'' are long and also extend the span of the WS.

During the flight the grippers must be in the hands and under proper tension.

To define what is the proper tension is hard to say, because it depends on each individual body distribution and flying skill.

BASEstore.it

[dragon2 0]

Spmething like this?
http://www.dropzone.com/cgi-bin/gallery/imageFolio.cgi?action=view&link=Personal_Galleries/dragon2/Wingsuit_Weekend_Teuge_09-2005&image=DSC_2317.jpg&img=18&tt=

Although there seems to be a lot of tension on the outer cell?

ciel bleu,
Saskia

[The111 0]

James, I'm sure you know what polar curves are. I've always wanted to find a set of WS stats tracking fallrate and forward speed so I could construct a WS polar curve. I don't have a GPS so doing it myself is out of the question. But I did find this old post. It may be only one set of data from one guy, but it's all I have to go by, so I plotted the points and lo and behold they actually do seem to construct a pretty accurate polar curve.

What are your thoughts about his assertion that fallrate for max glide is only slightly above min sink? Obviously this was for an S3, and each suit will definitely have its own polar curve.

There are so many variables involved in flight, it would be really hard (for me at least) to try to get some stats like this. I've had jumps where I hover around 35mph for the first minute (time is all I have to go by without GPS) but feel like I must be sucking because it is not tiring. Then I get really tired and think I'm hitting a good position but I'm actually in the high 40's. I don't think I'm accurate enough in my flying to try to intentionally fly certain speeds for an entire flight, well and entire long skydive at least. BASE may be a better environment for measuring this stuff. Heads-up display would make it nice too.

EDIT: Re-reading ManBird's post I realized he did it without actual GPS, but over terrain he knew very well.

www.WingsuitPhotos.com

[VectorBoy 0]

Matt, Unlike a rigid frame aircraft where the polars would
be the same for every unit built. A wingsuit would have polars vary for every different body that slipped a suit on. And they would also gradually change for the same body when, say for example, that flyers skill improves or degrade when that same flyer is tired.

[KrisFlyZ 0]

Quote

Spmething like this?
http://www.dropzone.com/cgi-bin/gallery/imageFolio.cgi?action=view&link=Personal_Galleries/dragon2/Wingsuit_Weekend_Teuge_09-2005&image=DSC_2317.jpg&img=18&tt=

Although there seems to be a lot of tension on the outer cell?

I am looking at the white wing and halfway down it looks like outward tension has deformed the wing from forming a smooth curve.

Kris.

[The111 0]

That's true Glen, but if we have Joe, Fred, and Hank all flying Classics and obtaining polar curves, and then Joe, Fred, and Hank all put on S3's and obtain polar curves, there will be a trend. While each flyer will have different polar curves, there will be noticeable similarities between all the Classic curves and all the S3 curves. It's still a worthwhile tool, albeit a difficult one to use. I already pointed out some of those difficulties (the main one in my eyes being we have WAY more control inputs than a glider).

And of course performance would degrade with fatigue, but honestly we don't need data from a whole flight. We just need data from a static portion of the flight.

www.WingsuitPhotos.com

[robibird 2]

Wingsuit is basically soft or semi rigid airfoil which inflates in first few second of jump/flight. But even if wingsuit looks and flies a lot like an airplane, great deal of things are making wingsuit very different from other rigid flying objects like airplanes, gliders, hanggliders and even parachutes and paragliders. All these objects are of definitive shape and are not changing much during flight.
On the other hand, human body is not a rigid object nor can it keep exactly same shape/position for a long period of flight so it is impossible to accurately measure number of things, including the polar curve. There are so many variables which must be taken into account, but can not be accurately measured, like change in lift/drag with change in body/arm/leg position, drag of particular part of wingsuit, inability to maintain proper body position due to tiredness and its influence on GLIDE RATIO, etc.

GLIDE RATIO is the basic data we need to see how particular wingsuit flies, not the polar curve, because the GLIDE RATIO is the most important measure of efficiency of particular suit.
Of course EVERY pilot will have different result because each pilot flies differently, has different body shape, arm and leg length, weight distribution (centre of gravity) and consequently different position of centre of lift even if using the same type of suit.

Additionally, on skydives (jumping from the plane) measuring the GLIDE RATIO is also not really accurate. For example, it is rather complicated to accurately account for momentum provided by the plane and for drift caused by the wind (and very often wind varies in speed and direction for different altitudes, and accurate data for that is almost impossible to get).

Wingsuit is very dependant on personal flying skills, and even putting the same suit on identical twins (or triplets or even more) would most likely produce very different results, even though they may have identical body shape and density. Then try to imagine the difference in results if we try to compare measurements taken from, for example, Denny DeVito and Dennis Rodmann, both flying the same type of wingsuit.

Testing the wingsuit in wind tunnel is very interesting topic. To find/measure flying characteristics on rigid flying objects (planes, gliders, hanggliders, etc.) is easy. Make the model in 1:1 scale (best but seldom possible) or 1:10 (or any other practical scale, depending on the available working area) and put it into the wind tunnel, fix it on aerodynamic balances and start the software and the fan. In few minutes you'll have most of the data, drag, lift, stability, etc......

To place the human (not fixed object) in the wind tunnel is not that easy.
First we have to find wind tunnel with working area big enough to suspend skydiver in. Next problem is how to suspend living human, without interfering with his natural or best flying position. And even if we succeed to do that, we do not have any guarantees that we managed to guess proper (or best) angle of attack for that suit and that very person. Most of the time we will be able only to see the air flow around the wingsuit and use that data to streamline or clean up wingsuit design. But that will work only for that particular person that was in the wing tunnel!!!!

Of course, we can make a scale model, but then we have another set of problems. First, who are we going to take as a model and scale him down (DeVito vs. Rodmann issue again). Then, how to make scaling. Use of three dimensional scanner of needed size, due to price, is out of question. Even if we succeed to get hold of one, how to ensure that scanned body position is actual body position maintained during flight, and that this is the optimum body position used for best glide ratio?

I discussed possibility of testing the wingsuit in the wind tunnel in order to get reall data, with some people from Faculty for mechanical engineering and conclusion was that, right now, the results would not justify the efforts and resources needed for that project.

Robert Pecnik
[email protected]
www.phoenix-fly.com

[mccordia 73]

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with some people from Faculty for mechanical engineering and conclusion was that, right now, the results would not justify the efforts and resources needed for that project.

Does anybody know if there was any valluable data collected (or used) from the tests that Patrick DeuG. Jean-Loic (or Matter, dont remember who that was, saw that somewhere), Adrian Nicholas and Birdman Inc. have done?

It just seems soo weird, and totaly puzzles me as to why so many companies would put up the money for something that would seem to be more or less useless (in terms of the profit it would make, designwise)

Did they all put their efforts and resources into that for the greater cause, or where all of those done from a PR/commercial standpoint?

JC
FlyLikeBrick
I'm an Athlete?

[KrisFlyZ 0]

I heard direct from Loic that someone from the university wanted to do a study on his wingsuit design. He did not say that his design is wind tunnel tested.

I don't know about the rest. I have opinions as to why some companies needed to do that but, they are not appropriate for this thread.

Kris.

[The111 0]

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But even if wingsuit looks and flies a lot like an airplane, great deal of things are making wingsuit very different from other rigid flying objects like airplanes, gliders, hanggliders and even parachutes and paragliders. All these objects are of definitive shape and are not changing much during flight.
On the other hand, human body is not a rigid object

In other words, what I said here.
we have WAY more control inputs than a glider

Quote

GLIDE RATIO is the basic data we need to see how particular wingsuit flies, not the polar curve

Actually, if you have the polar curve you have the glide ratio data you are looking for, and then some. However, I am not sure a polar curve for a wingsuit would be a "curve". I am throwing out a wild guess here, but I would bet that for a specific person in a specific wingsuit, instead of a 1-d "curve" you would have a 2-dimensional area, since for any given fallrate (most of them at least) there is an entire SET of forward speeds possible (this is a good thing, it is what allows large flocks made of different suits and different people to work!) This is true more in the "middle" of a suit's performance envelope. (Just bear with me here and assume it would be possible to actually gather all that data ) See the attached jpg with my amazing artwork. What do you think about this "2-d sweep" idea?

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the GLIDE RATIO is the most important measure of efficiency of particular suit.

Correct, with a small caveat: glide ratio is the most important measure of [glide] efficiency of a suit. Distance isn't the only reason for flight.

Quote

Wingsuit is very dependant on personal flying skills, and even putting the same suit on identical twins (or triplets or even more) would most likely produce very different results, even though they may have identical body shape and density. Then try to imagine the difference in results if we try to compare measurements taken from, for example, Denny DeVito and Dennis Rodmann, both flying the same type of wingsuit.

Then we should have a very skilled pilot gather the data. It may not truly represent the limits of the suit, but it's a start certainly. And yes, there are different body types, but a data set for ONE body type is still better than nothing. There are a variety of solutions to this problem, none of them perfect.
1. For an accurate comparison of suits, we could have one single person, equally skilled in all suits (pretend that's possible ) gather a data set from each one.
2. We could develop rules of thumb for looking at a skinny person's data set for wingsuit "x" and predict what that same data set would look like for a fat person on same wingsuit "x". And so on.
3. We could have an equally skilled (yes, I know that's hard to achieve!) skinny pilot and fat pilot gather data sets for the same suit. This would help develop the predictive rules described above in #2.

With regards to tunnel testing:

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Most of the time we will be able only to see the air flow around the wingsuit and use that data to streamline or clean up wingsuit design. But that will work only for that particular person that was in the wing tunnel!!!!

I don't think that's fair, anymore than saying "skytesting" a wingsuit will only present results valid for the person who flew it. Sure, the results will differ from person to person, but something learned with one body type is still valuable.

I appreciate your lengthy and unbiased opinion on tunnel testing, but considering I didn't ask about that, I'll repeat my original, unanswered, question (the one your reply was directed toward):
What are your thoughts about his assertion that fallrate for max glide is only slightly above min sink?

www.WingsuitPhotos.com

[The111 0]

Quote

I have opinions as to why some companies needed to do that but, they are not appropriate for this thread.

Then why insinuate them?

www.WingsuitPhotos.com

[KrisFlyZ 0]

Quote

Quote

I have opinions as to why some companies needed to do that but, they are not appropriate for this thread.

Then why insinuate them?

What is your question about?

That sentence "completed" the reply to Jarno's question. By covering the remaining companies mentioned in his post.



The article posted in this thread provides valuble information. Now, can we remove split off discussion(starting with your post about polar curves) from this thread and make the original posts a sticky?



Kris.

[medusa 0]

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Did they all put their efforts and resources into that for the greater cause, or where all of those done from a PR/commercial standpoint?

I don't know if I'm right but as far as I understand they were doing the wind tunnel testing for the developing of the new generation of advance wing suit "Blade S5".

So I guess we all will have to wait for the suit to be ready, in order to see the results of the wind tunnel testing and to gudge is this wind tunnel testing was a vain effort or not.
.

Medusa

Get Killed or Die Trying!
Patent pending ATFK15456

[robibird 2]

Quote

***
What are your thoughts about his assertion that fallrate for max glide is only slightly above min sink?

Of course it is above. Putting the answer that way:
''slightly above.''
What we have?! Is this hard data?!
To get the polar curve for WS is almost mission impossible. (unless we hire NASA)

I mention tunnel as well to give the thoughts about what we can get there. What is possible and what is not.....

Robert Pecnik
[email protected]
www.phoenix-fly.com