swing nyos rs information

Swing Nyos RS Videos

RAST Videos
https://youtu.be/CiV5snLNrx8 - shows rast in action, limited turn or dive

http://technology.swing.de/?lang=en  transcript of a talk by the designer, notes below

67 page pdf on RAST at bottom of this page. 

Nyos RSMedium


LTF homologation


CEN homologation

Take off weight (kg) min./max. inkl. Equipment85-105



Wing area (m²)


Wing area projected (m²)


Wing span (m)


Projected wing span (m)


Aspect ratio


Projected aspect ratio


Glider weight (kg)


Max speed (km/h)

52 ±2

Trim speed (km/h)

38 ±1
Swing Nyos RS Ziad Bassil review 3/20/2018
The last Swing glider i flew with the RAST system was the Arcus RS, and here’s the new high-end B from the same manufacturer, the Nyos RS in size S (75-95) flown at 93.5 all up with an X-rated 6 harness.
The Nyos RS construction holds a normal nose. The lower lines are sheathed with the higher ones unsheathed. The lines are slightly thicker than the competitors in the B category.   
Launching is quite easy in nil wind, and even in strong breeze. The Nyos inflates quite smoothly and evenly.
First turn, i could feel the moderate to short response on the brakes, with quite a nice agility in thermals ! The Nyos RS turns quite flat with moderate pressure on the brakes and could be described as quite agile! It doesn’t handle like an acro wing for sure and it’s not suppose to, but for a handling seeker like me, it’s very satisfying ! Thermals can be cored very tight, even the turbulent ones. 
The handling alone doesn’t really matter sometimes if the glider above the pilot is jumping around all the time. Underneath the Nyos RS, the movements in turbulent air can be described as “computerized self controlled” , as the Nyos RS feels very compact and super smooth to fly !
I flew this glider in some turbulent air, and got myself into a sunny lee side of a cliff, when the wind was blowing around 20 km/h from the other side. Usually the experience is not really joyful…but it was quite soft on the Nyos RS ! I got a bullet thermal that got me into higher layer, and kept my flight going on further.
I have been flying this path for a very long time, and underneath plenty of gliders. The Nyos RS was the coolest, most reassuring, comfortable glider ever to be flown among B’s ! 
The experience flying the Nyos RS is exceptional when it comes to comfort ! Even compared to some low B’s !
 Having said that, the Nyos RS could not be considered as a dull glider at all. 
It will inform the pilot about all the movement of the air around, but with such rare serenity and homogeneity and an efficient leading edge that surfs the airmass moving constantly forward in a super smooth way ! Incredible ! All that, led me to say, that the Nyos RS is indeed “The Rolls Royce of the sky”  ! 
Even in turbulent air, there not pitch back ! The Nyos RS just simply move forward quietly with that amazing solidity and super cohesive structure ! Some B gliders will have sharp movements, or a bit of yaw, some pitch…But not the Nyos RS. It just inform the pilot and filters wisely only the excess of turbulence !
Gliding with top high B gliders in moving air, i could notice that the Nyos RS is very competitive, and i could put the gliding efficiency among today’s top four, high-end B gliders.  
The interesting part of the glide in turbulent shaky air, was the easiness of the C risers control.  Using the bar in total confidence with the C riser control will deliver a quite efficient glide and they are super easy to use with moderate and progressive pressure. If only a thinner line version would be feasible, it could perhaps squeeze up even more overall performance to dominate the category.  
Climbing in weak and strong could place also the Nyos RS among the top 5 gliders in the high B category.  
Ears are stable, efficient, and reopen without pilot input. 

The pluses:  The ratio of usability ! I mean exceptional comfort and homogeneity with smooth information coming through! 

Conclusion: The Nyos has a normal nose, normal width lines, yet it glides beautifully and efficiently into wind. As for the flight characteristics and compact structure, I can totally confirm that the Nyos RS has somehow a different feel from many B’s i have tested. It has a very taught, super homogenous structure, with precise and direct brake response.  The comfort flying the Nyos RS is very high. Pilots flying in strong air and alpine conditions wishing for a solid, well mannered companion, should strongly consider flying the Nyos RS as a good option.  
I’m not an engineer to talk about RAST and the benefits that comes along…but it seems what i have experienced flying the Nyos RS couldn’t be understood otherwise. 

Posted by Ziad Bassil at 10:44 PM  March 20, 2018
Pilot review Feb 12, 2018
Thanks Matze - translation... 
Today the 500km in 5 days full. And best of all, the glider is so easy to fly that it could just go on like this. But let's start from the beginning: the Nyos RS is already super easy on the ground. The line configuration is so clear that a hooking never occurred, because the Chili4 and Delta3 were much heavier. At the start, it is enough to lay down the shade loosely in the rosette, pull out a piece on the left and right and the glider starts like a training parachute - absolutely consistent and homogeneous. In the air you can feel little of the RAST in normal, quiet conditions, but the NyosRS rises extremely well! It gets really interesting when it is thermally torn and bumpy. So I got a lot out of it with the RS. In general, the RS is very good at climbing. With the accelerated flight it is immediately noticeable that the first step is very easy up to approx. 50% and the profile nose is very clean in the wind even when rolled on a roll! I've never had it like this, I think Nitinol comes into its own here. By the way, thanks to Nitinol packing is easier than ever. The rods are extremely short and flexible. In flight, the comparison with the latest High-B and C-screens was great, the RS flies with absolutely equal, I'm even longer in the gas stopped because the RAST swallows much and makes the screen stiffer. The C-control is a poem, so I stayed in 4-5m thermals even in semi-gas loosely. The handling with RAST is super easy, the screen turns extremely willing and is great at rearranging, while others are thrown out in disgusting beards. For me also a safety plus. In order to use the RAST properly, one has to "pump" in thermics to get it to its full effect. I had two rattles with half throttle and full throttle, but only 30% and they stayed relaxed on the RAST wall. Screen just flew straight on. Totally easy. Wingovern goes great with the screen, you're over it quickly. Spirals up to about 12m was also super easy and the screen can be followed by a nice draw. Landing nothing conspicuous, flies out dynamically. All in all, the wing was super nice for me and easy to fly, despite my 4 month break, I was immediately in there after a few hours and was able to get the full performance. A real XC workhorse
Pilot review March 11, 2018
My NYOS RS medium finally made it to the USA and I now have three flights and almost 7 hours of airtime on it. I think it is important to explain why I chose the NYOS RS. I started hang gliding in 1980 and paragliding in 2001. In all of those years, I had suffered only a broken arm in one incident on my hang glider and had never been injured on a paraglider. Unfortunately, in early October of 2017 I crashed my paraglider on the top of a mountain and broke my pelvis, fractured my ankle and tibia and suffered some other minor injuries. I am about to turn 65 years old. As you might imagine, thoughts of whether I should continue to fly, and opinions of others regarding the same, became pretty prominent as I recovered from my injuries. Ultimately, I decided that I needed to keep flying and my wife eventually came around in full support of that decision. So the question became whether I needed to make any changes in my flying or my gear. With plenty of time on my hands while recovering, I began reading about RAST. I read and watched everything available about the RAST system. I became convinced that RAST adds substantail passive safety to paragliders. Others may agree or disagree, but I made up my mind that I was going to return to flying with a RAST wing. It seemed like my only choices were going to be the Swing Mito or the Arcus RS as that was what was on the market. I strongly considered the Arcus but I really wanted the performance of a mid or high B and the Arcus specs seems to be more in the low B category based on aspect ratio and cell count. Then news of the NYOS RS became available. For me, that seemed like the solution to what I wanted--the best possible passive safety with high B performance. I wanted a RAST wing and so I ordered the NYOS RS. 

I fly primarily at high desert sites in New Mexico and in the mountains of Southern California. I live for thermal flying and we get plenty of those in New Mexico, most of which are strong and textured and can take us up to our legal altitude limits in summer. Most of my launches are hike and fly that give me only about 800 to 1000 feet of vertical over the ground. So when you hit a thermal, you have to hang on to it or you may be on the ground quickly and forced to hike up again. Having to hike to launch usually leads me toward light wings but Swing is not making a light version of the NYOS RS. It is "semi-light" at 5 kg so I have to live with a couple of extra pounds on the hike but that's a small price to pay for the safety of RAST. Handling was a big concern for me since I live for thermaliing. My all time favorite wing was my Skywalk Arriba which would turn on a dime and thermal like a spinning top. Having read about RAST wings, I was fairly confident that I was not going to get that same handling with RAST and that proved to be true. So with that background and those thoughts, I headed out to Southern California to try out my NYOS RS. 

My first flight was at the Marshall launch in San Bernardino. It was not a perfect day as it was blowing North at the Crestline launch above us but was blowing in nicely from the South at Marshall. So we knew ther would be some mixing air above. Launching the wing was very easy in the moderate thermal cycles even without having even kited the glider. I also was flying with a new harness (better protection also) and I had a problem with the speed system that prevented its use and was causing me to not be able to fully get properly seated in my harness. I couldn't correct it in flight and just decided to live with it as I flew for an hour and 18 minutes. After a few minutes trying to get the harness issue resolved and giving up on that, I grabbed my first thermal well below launch. A pull on the brake resulted in an immediate turn into the thermal without any hesitation or yawing. The brake pressure was moderate but the control was very precise. I climbed out in that first thermal to the cumulus clouds that were forming above launch. The wing felt rock solid during the whole flight. I took one tiny tip collapse that was gone immediately. There were few pilots flying that day so I didn't get the chance to compare performance against other wings. But overall, climb seemed strong and glide felt good. 

The next day I flew at Lake Elsinore in moderate thermal conditions. Launch in the thermal cycles was without any issues. During this flight I was able to fly near a friend who was on a BGD Cure and make some comparisons. Our climb rates were very similar. Our trim speeds also seems about the same. He did seem to have an advantage on glide at speed although not more than expected from a high C wing. On this flight, I got to test the wing's ability to climb in light lift as I got low on three occasions. A local pilot told me later that he thought I was going to sink to the bailout field each of those times but instead I scratched my way back up. The NYOS RS proved to be very good in the light broken lift I used to climb out of those situations. It's hard to explain the feedback you get from the wing. The best I can do is to say that it told me everything I needed to know and nothing I didn't need to know. My Arriba gave me a lot more feedback in active air as it moved around a lot. The NYOS RS does not move around in a similar way but just feels solid and goes where I tell it to immediately and climbs in the lifting air. Anyone concerned about its ability to climb in light lift can forget that concern. You will get less feedback than may be typical but you get all that you need. The proper word for the NYOS RS is comfortable. It doesn't make you work hard. In fact, my friend on the Cure later told me that he was working constantly to keep the Cure solid above his head. I was in the exact same air and I definitely did not have the same feeling on my wing. I took one small tip collapse what was gone before instantly. There is very little pitching from the wing. While I was flying actively, the wing wasn't asking much from me. I'm not sure it needed my help at all. It also felt great on speed bar, again being rock solid. Pressure on the bar was very reasonable. I ended up with the longest flight of the day and got the highest of anyone flying. 

The third flight was again at Elsinore in very light thermal conditions. My impressions of the wing were the same. It climbed great in the light lift, always felt solid, handling was precise and immediate. 

As I had suspected, the wing was not as agile as my Arriba. I wish it was but I don't think the lack of agility is costing me any performance so I can live with that. During these flights, I never felt like the wing wanted to sit on its tip and crank around in thermals like my Arriba. Don't get me wrong. It banks over nicely and let's me work tight cores but it's just different in how it does it and it doesn't seem to want to bank as tightly as the Arriba. It seems to prefer flatter turns. I guess that is because of the RAST system or maybe it's just the overall design of the wing. But what I do have is a wing that is just rock solid and gives me incredible confidence that I'm not going to be dealing with many substantial collapses as I fly through the thermal filled sky. I am really looking forward to putting it into those strong desert thermals this summer. I am confident that I made the right choice for me.
Pilot review March 12, 2018
My own experience with my Nyos RS after 4 days and 11 hours in Bright, Australia is a bit different than Bo's in some ways, similar in others. One of the things that's hard to assess, unless there are a lot of other wings around, is how turbulent the air really is. I've asked the locals and have been told that they've considered the conditions moderately turbulent, and I've seen a few other wings take some deflations. I've certainly had a few minor ones in those 11 hours (and my understanding of the RAST system is that it shouldn't decrease the frequency of tucks and deformations really, just reduce the size of them and likewise reduce the time it takes for them to come out). More specifically, I've had about 4 tip tucks which came out instantly. I was able to catch a glimpse of one before it came out and could totally see the "wall" that the RAST system makes, preventing the tuck from becoming anything larger. I've also had one very small frontal where it didn't even progress as far as the RAST wall before coming out. It never involved more than about 25% of the leading edge so I don't know if the RAST system had anything to do with how small it was. 

I've also had two deflations of about 25% (or 1/2 of one side of the wing) on the inside of the wing while thermalling, which isn't something that I experience that often. Normally I would be more concerned about a deflation on the inside of the turn as I've got both some brake and weight shift on. Both times I would say that the deflation moved a bit past the "wall" at its greatest extent but it came out really quickly with no tendency to spin and really no change in the radius of my turn. It did make me wonder whether having the brake on for an extended period of time might cause some "leakage" of air pressure from the back of the wing to the front, as suggested in someone's review of the Arcus RS. I haven't tried the technique that person recommended (if I recall correctly) of letting off the brake for just a half a second every turn or so but will experiment with it.

Overall I would describe the wing as feeling very solid and reassuring. Hard to say if this is more psychological or real until I've had some more hours in places like the Alps where I better know how to gauge the air. But psychological effects are still important! Very Happy 

As for performance and handling, I've been in the air mostly with Alpina 3's and Sigma 10's and the Nyos RS does just fine in comparison on glide, with some clear but slight disadvantage into wind on more than 1/2 bar. I am still getting used to the handling, having flown mostly Ozone wings before. I would say that though it climbs fine in smooth, wide lift, it doesn't have the same agility as a Buzz or Rush or Delta, so I'm not (yet) able to put it exactly where I want it in lift that is less uniform. When the thermals are broad, it's a non issue, but when they are small and "lumpy", I find myself getting pushed around a bit more than I am used to. I suspect most of that is just me getting dialed into the wing. I would describe the brake pressure as on the higher end of moderate and was a bit tired at the end of a 3 hour flight yesterday, but it's not so high as to be an annoyance at all. 

Will report further when I have more hours. But happy enough so far.

From the Swing website http://swing.de/nyos-rs-en.html March, 2018

The NYOS was the glider flown by Didi Siglbauer to win the DHV-XC two years in a row. The success strategy behind this glider is entering its next phase with the NYOS RS!

The main difference between the NYOS RS and the NYOS is the fact that it is much easier for pilots to tap into its performance potential because of the increase in stability and control.

Requirements for the NYOS RS

“Can’t you make it with much higher aspect ratio? It’s just so easy to fly!”

That’s what we heard most often from pilots flying the new NYOS RS during field testing.

Yes, we can do that - and we have! There was minimal performance increase though since there is little room to improve glide and climb within the EN-B class.

In our opinion and from what we have experienced, the NYOS RS is the easiest and most pleasant glider to fly currently available in the high end B category. The pilot stays in full control even in incredibly turbulent conditions, thanks to RAST. If there are nevertheless any disruptions, in the vast majority of cases, these are stopped by the “wall”. Dynamics, demands on the pilot and loss of altitude are often even less than with current EN-A gliders. The more turbulent the air, then the more marked the difference from gliders without RAST. When pilots flying gliders without RAST are already starting to notice unpleasant turbulent conditions, the NYOS RS continues to convey safety and a good feeling during flight.

We are confident that there is no other glider available which matches its combination of safety, damping, performance and handling – making the NYOS RS the first in a new class, the comfort-performance class!

NYOS RS - an innovative work of art


The NYOS RS uses the latest generation of our bulkhead partition system with non-return valves and perfected tension distribution.

A third level of tension is created above the pilot (in addition to the leading edge and trailing edge tension), providing a completely new feeling of stability.

The NYOS RS is now brought into the EN-B performance class for the first time by this new RAST feeling, which you can read about in all test reports of other SWING gliders with RAST.

It would be hard to get a more functional design of the RAST system under the certification requirements than we have with the NYOS RS. It was very difficult to provoke the collapses required for certification in the specified measurement field. The norm would have to be altered for even greater stability. Collapses across the wing chord and front stalls with great loss of altitude are extremely unlikely with the NYOS RS. We have not yet experienced any collapses or front stalls in actual flight where the folding angle was not reliably stopped by the RAST wall – and before the pilot was able to intervene. Our test flights and simulations are not carried out only over water. Particularly in testing RAST, we intentionally seek out challenging flying days in the Dolomites during spring and summer, so that we get findings under real conditions!

The result: it has never been so easy to use the full performance potential of a paraglider even in tough conditions – thanks to the 10 advantages of RAST.

Nitinol-leading edge reinforcements

The leading edges need to have the most stable shape possible when it comes to maximum performance and stability, particularly at full speed.

The disadvantage of traditional plastic stiffening is that it has a predetermined curve, which can reduce stretch in the leading edge.

The solution is to use rods made from the high-tech memory metal Nitinol.

These are inherently straight and stretch the leading edge like a drum, when fed into the guide channels.

Nitinol is a nickel-titanium alloy used in medical engineering because of its dimensional stability, e.g. in dental braces, glasses frames and fixation devices.

All leading edge reinforcements for the NYOS RS are manufactured from this quality material. This means that you neither have to pack up the NYOS RS painstakingly cell by cell, nor leave it unfolded if you are not flying for a long time.

Simply roll it up, compress it firmly and you already have the pack size of a small mountain glider!

Modern new fabric

You can’t fail to notice the new glider fabric used for the NYOS RS. It is shinier, comes in a range of new colours and feels different to the touch from regular fabrics. The material was developed in close collaboration with our supplier and was optimised for use in paraglider manufacture. The new high-tech fabric is extremely lightweight and stands out because of its above-average form stability, tear resistance and durability.

Optimised profile

The profile of the NYOS RS is a logical refinement of the tried and tested Nexus profile. Most performance gliders fly best at the upper limit of their specified weight range. This is not the case with the NYOS RS: speed and performance are nearly identical across the entire weight range.

Consistent lightweight construction

The profile ribs and diagonal ribs have been made thinner, without weakening the strategically important load points. The diagonal ribs are sewn down along the cut edges (and through to the back in the C/D level) so that they stay the same length over a long time even in tough conditions.

Riser perfected for accelerated speeds

It’s not much help if a glider can fly fast but your kneecaps suffer in the process! That’s why we spent a good deal of time and energy on the risers for the NYOS RS. Minimal force is needed when accelerating and the full throttle position can be held for a long time without causing cramp.

C steering

We had originally linked the C-riser steering with the B-level. In practice we couldn’t find any advantage to this with the NYOS RS: deployment force was too high and too much speed was lost on stabilisation. What has proved most effective is the C-bridge, where the wing tips and the centre section can be stabilised separately or together, depending on how the C-bridge is pulled. This is used in the NYOS RS and allows precise adjustments even at full throttle, without losing speed.


We thought a lot about how to describe the NYOS RS as objectively as possible and without exaggerating. Anyone who has ever flown the NYOS RS agrees that the NYOS RS is incredibly simple to fly, particularly in turbulence and strong thermals, really fun, and you feel extremely comfortable with this glider.

Talk by Michael Nesler:

(German presentation on Youtube) www.youtube.com/watch?v=m9MjH2LkY6I


A year with RAST – Experience and findings

Last year I presented the RAST system, which was a new concept. I’m not sure if anyone present today was here for that. We have been inventing and testing a system that makes paragliding safer, and offers some other refinements as well.

Now that we have been experimenting with it properly for a year, and have even manufactured some series gliders featuring it, I have been asked to talk about what we have actually achieved during this time, how the year went, what we discovered in the way of advantages and disadvantages, in other words, simply to give a brief overview.

Just by way of introduction, for anyone who doesn’t know or hasn’t heard about the system, we came up with the idea of dividing the glider into two sections, in a lengthwise direction. We have a front section – and here you can pretty much see the partition – in yellow – which seals off the front and the rear sections …

… in other words, to start with, when you inflate the glider, the front section fills first and then, after a brief delay, the air goes into the rear section and, if there is any kind of malfunction, the rear section initially stays inflated.

Now, something that has often been asked in recent years is if there wasn’t already a rigid system in the past? People are always saying it. And I did have some involvement in that. In earlier times we made gliders with pressurised air bars, inflated, which then generally burst above 3,000 m … and other things.
Then we tried all sorts of things with poles in the trailing edge, i.e. tent poles, made of aluminium, carbon rods, then there was fibreglass such as LTK with the Panther. And we kept on trying ways to make gliders rigid.

And it took a while before we realised that making the glider rigid actually achieves exactly the opposite to what we want. Sure, it no longer collapses, but instead it flies towards you or under you. The paraglider is actually an ingenious device, so it dissipates the energy, by becoming deformed instead of flying somewhere where it shouldn’t go.

So, as with a hang-glider, it can of course happen if it doesn’t yield, that the energy has to go somewhere, then it can tuck or tumble – that means it swings around. And we have to cope with that.

With the paraglider, it is true that everyone would be happy with the idea that a paraglider can no longer collapse. But then we would pay for that by the glider diverting the energy differently, instead of collapsing, as I said before. Then it would either fly towards me, somersault, fly under me, then at some point I’m caught up. And that’s not what you want.

That’s why some time ago we completely gave up again on making them rigid. But now we have the situation that the biggest problem with the paraglider, if it collapses, is that the canopy completely empties. We know the collapses are harmless, if the trailing edge is not affected by the collapse or front stall, i.e. if the trailing edge at least to the middle is still intact.

Then the idea was that we would have to find or invent a system where the trailing edge always remains intact, that in practice the air there cannot get out and at the front where the issue is, i.e. where the lift is created and the momentum is created, that the section can still collapse, empty and thereby discharge the energy if the glider gets out of control.

And this has been working very well. You see at the top a conventional division without a partition, without RAST, and below a dividing partition is incorporated, which may or may not have valves depending on what is needed, and which allows the air into the rear section after some delay and lets it out again even more slowly.

RAST Swing Paragliders

That means that if something dynamic happens, such as a collapse etc. then it takes a while before the rear empties, the trailing edge remains intact, there is less rotation and most importantly less forward momentum.

What we expected from RAST:

  • improved inflation behaviour on launch
    This has proved relatively good in practice. I’ll come back to this point…
  • improving the problem of the pilot being launched unintentionally in strong winds
  • the glider “aligning itself to the slope” in a tail wind
  • resistance to large-scale collapses
  • preventing the dreaded rosette on a front stall

We have now drawn up a table, because we have made a large number of prototypes and carried out many test flights in various classes. We have tested out virtually everything from EN-A to EN-D, with and without the partition.

Which really works and can be mastered by every pilot?

  1. doesn’t work
  2.  works only under certain conditions (e.g. if the pilot can cope with it)
  3. works to some degree
  4. works satisfactorily
  5. works 100% reliably

We have already made some series gliders, and we have of course analysed market feedback. It is obviously difficult being the only company on the market for the moment to have a completely new system. One encounters a good deal of resistance from the other manufacturers and distributors, that’s normal, we were expecting it too. And that’s why we were actually expecting market feedback to be mixed…surprisingly, however, it was extremely positive, even from companies who are in direct competition with us.

They said to work on it a little more, and in a year we’ll talk about whether we maybe continue it together. Meantime we’re at least to the point where there are at least two major manufacturers wanting to work with us on it. Let’s see what the year brings in that respect, that would of course be interesting, because this shouldn’t be something which just one company has, rather it’s really about we as pilots also getting the benefit. It doesn’t matter what brand is on it now. …

We have of course made the beginner wing with basic RAST ….

(MITO) … which is now trend-setting when it comes to launch behaviour, very comfortable in extreme flying manoeuvres and there were absolutely no complaints with regard to stiffness or that it somehow attracted negative attention. On the contrary, the people who are using it for training are very satisfied.

Market feedback so far:

Series gliders:

  • MITO with RAST 1.0 → launch, extreme flight behaviour, no complaints
  • TWIN RS Tandem → launch (pilots need to adjust somewhat, thermals and control very good)
  • APUS RS Miniwing with RAST 2.0→ 14, 16, 18 certified with extremely long speed travel, excellent feedback (Kilimanjaro, Freestyle)
  • TRINITY RS 23 → first acro-glider with certification
  • ARCUS RS The first time that a low-end EN-B glider on the market has RAST.
  • MIRAGE RS The first Speedwing on the market has RAST.

It was a little different with the tandem. The tandem is an experiment. With the tandem, we have incorporated RAST in such a way that it also has a bearing on its characteristics in thermal flying, not only on launch and safety. Another point is that tandem pilots of course like to launch by running like mad and trying to get the wing above them as quickly as possible. Then it usually happens that the glider overshoots and is braked hard ,and you do of course see a good deal of video footage of tandem launches where the brakes are nearly at 100%, because the glider is simply too far forwards. RAST doesn’t like that. In other words, if I overbrake, then the glider is not able to inflate at the rear and the take-off run becomes a bit longer. Then you simply have to tell people “take your time when launching, no stress –it’s inflated at the front so it will hold”.… except you are braking at the back. And interestingly, you believe it if you’ve tried it a couple of times. As a tandem pilot you are less likely to believe it. And then the take-off run suddenly becomes shorter again.

(Audience question: Winch) … yes a lot. Flatland Paragliding is as it were part of our extended test team, which tests it all on winch. And it is also a matter here of simply inflating comfortably and then off you go. And on winch it doesn’t matter whether or not the rear section is inflated, because it is actually already holding at the front. Because you are of course under tension.

….then we have the miniwings with RAST 2.0. 2.0 just means that there are additional valves in the partition which, as soon as there is any kind of disturbance, seal off the rear section further, so it is even harder for the air to get out …
surprisingly with that we have certified 14, 16 and 18 m² up to 100 – 110 kg, partly in the B- and partly in the C-category, and even though they are 14 or 16 m², which were really overloaded. Particularly with the small gliders, this is what was most surprising (you’ll see a few photos later and I can also show a short video): 1) it is extremely difficult to get major collapses, you have to use both hands and full throttle because RAST of course is working against it…and 2) if the wing disappears, reinflation to just a few metres is less than one second.
You also have to get a bit accustomed to the fact that a glider, if it completely disappears, flies straight quite normally again after a second, but it works. But that it also just a bit of adjustment.

And what the RAST system has also allowed or enabled us to do … we have for the very first time in history, I believe – if I’m not mistaken – a certified pure acro-glider.
This has the RAST system and it was of interest not only for safety aspects, so that collapses and front stalls etc. fall within the certification limits, but with the TRINITY RS with RAST, it is possible to fly manoeuvres which are not even possible with a normal glider. That means I can, for example, if the glider is still under me, start a heli from a dynamic full stall and go into the heli without any transition. Or I can simply send it out of a heli and immediately go into a SAT, without the glider briefly having to gain momentum. Because the rear section does not empty and momentum is not lost.

Then we still have the ARCUS RS in the pipeline. This is the first time that a low-end B glider with RAST will be available. Just certified, at least in size M, and we’ll see what happens from there.

What we weren’t expecting:

People who don’t have RAST do whatever they can to run it down:

Before anyone was even able to test RAST!

The opposition from the industry is unexpected: instead of other manufacturers being interested in it, to begin with there was only criticism (with two exceptions).

This shows that, for the market, it is not really about safety and improvements for pilots but, as always, only about pure profit.
Reinforcement has never worked … this is not wrong as an argument, but in this case it can’t be strictly applied because of course the front section can collapse and only the rear section is somewhat more rigid.

doesn’t work … all I can say to that is try it for yourself! I can’t convince you or prove it. You simply have to try it for yourself.

not much changes in the certification … this is also a small problem with which we have to deal … it is hard with RAST to cause collapses which come within the measurement field, i.e. I have to pull down harshly, I have to use tricks or ploys, I have to pull down the A- and B-risers on one side simultaneously just to cause the collapse, and either it is too small or it is beyond the line and too big. However the situation is such that I can only get a certification if I come within the collapse field. And then it gets difficult for the test pilots – is it better to take the one that’s too small or the one that’s too big? And we are then in some instances 2 categories apart. And this means it is also to some extent the case that the time we are now investing is not about whether RAST is working better or worse, but rather we have to find a way that I still somehow come within the ramge for certification and RAST still works well. And that involves firstly the positioning of RAST, how far to the rear or the front to position it and secondly how sealed the valves are. If I make the valves completely sealed and I position the RAST between B and C, then there are hardly any more collapses, but nor can I get any gliders certified. And now I gradually move towards the C level and try to find a compromise somewhere. This has worked relatively well for us with the new ARCUS RS, as we have upper limit all A and lower limit we have 1 or 2B – I believe – and this is also typical of RAST … the more weight is on it, the more stable it becomes.

Now let’s look at point 1 – Inflation behaviour on launch…

Better inflation behaviour on launch – 1.

RAST Swing Paragliders

Typical for RAST: the whole canopy is inflated at the front and the rear section is still empty, and that works very reliably. The interesting thing is that if you inflate a glider and it is inflated fully at the front but empty at the rear, as in the photo, then this has an interesting effect: it inflates, is stable, stays above the pilot’s head and it does not overshoot, because in that moment the profile is auto-stable, i.e. it is still not inflated at the back, this is a type of reflex profile …

RAST Swing Paragliders

This has several advantages:

1. it does not launch the pilot unintentionally, regardless of how strong the wind is

2. it doesn’t overshoot

3. regardless of how powerfully the student or the pilot runs, you will no longer have the effect that the centre collapses because the rear section fills first and the air does not go in quickly enough at the front. Here it is completely the opposite. I can also run full speed, it promptly inflates fully at the front, nevertheless rises above the pilot and it normally doesn’t overshoot. This has worked well so far.

The same thing in strong winds …

RAST Swing Paragliders

You see above that the profile is still empty at the back in the inflation phase – this is a type of “self-stabilising profile”, and in the middle it is then fully inflated, and then it really starts to carry properly.
We’re talking here about ½ – 1 second which you save on launch, but that is quite a considerable time on launching, before the profile carries. This is usually the exact length of time the pilot needs to turn around comfortably.

And this also works really well! We were in South America for 5 weeks with extremely windy launch sites, and in particular, in some instances we were doing cliff launches. And it was very pleasant not to be immediately launched off whenever the wing was inflated.

RAST Swing Paragliders

You can see this again here: the front section is fully inflated and the rear section is still slightly empty. The pilot is running directly towards the glider…it is also important if it is very windy on launch to always go towards the glider, relieve the pressure, so it rises comfortably.

Inflate the glider firmly and run up gently, there’s no more stress on launch. If it’s fully inflated at the front, then it will carry.

The next point …

What happens now with a tailwind, if it needs more until it inflates….

We somehow came across this by chance. We were at Stubai during the winter, where there is of course always a tailwind with snow…and we thought, hmm, this is going to be exciting now, launching here with a tailwind. And we launched at the same time with 3 tandems, with RAST, and interestingly enough we were airborne after three steps. And anyhow we thought: this isn’t what we’re used to…we filmed the whole thing from the side and worked out that in a tailwind the normal gliders try to line themselves up with the gradient of the slope …

In a tailwind, “aligning itself with the direction of the slope” – 2

RAST Swing Paragliders

In a tailwind, “aligning itself with the direction of the slope” – 2

…just like the orange glider here without RAST … it is just always a bit further ahead, the wind is coming from above downwards, following the slope, and thus the canopy adjusts itself to its normal glide angle as well. That’s why the canopy (without RAST) overtakes us if we’re inflating on a slope regardless of how fast we run, it is always further ahead, I have to brake and I have to run after it like a madman. This is completely normal, we’re all used to it.

With RAST …. Interestingly, if the RAST remains more or less sealed, I inflate the glider but it doesn’t overtake me. It stays in the angle above my head, the profile is auto-stable, it can’t easily follow the slope…. This means, firstly, I don’t have to run off, I can instead take my time and, secondly, I am actually running down the slope with, comparatively speaking, a very high angle of attack, i.e. instead of the 5-8 degrees to which the glider normally orients itself, we have 10-20 degrees, without having really braked already, and it becomes airborne much much sooner. I can’t tell you everything here of course, the only way to really believe it is to have a look some time or try it for yourself…for me this is the most astonishing effect of RAST.

The next point… once again relating to safety…

RAST is not a miracle cure for collapses. Nor should it be, because the glider should of course dissipate energy, it should collapse, it should go into a front stall, if you fly anywhere or carry out manoeuvres where there is simply too much energy. The glider has to dampen it. And naturally there are limits for every safety system or for every stable system. If you exceed the limits, then it’s no longer as it should be.

And we have two different possibilities:

If I fly actively, then every time I apply the brakes, the internal pressure in the rear section increases, i.e. by active braking I make the rear section much much more stable than it would normally be. And at that moment when it shakes, when it somehow gets really turbulent, and I go actively on the brakes, I increase the pressure still further and, even if it has a frontal collapse, it almost can’t collapse through to the back so that the trailing edge collapses with it. We tried that often, and it always worked well.

It is different with passive flying. If I do nothing with the brakes, then I now have at the rear a section with increased pressure, the collapses are indeed extremely delayed, they are not as big as they would normally be if one does absolutely nothing, but I cannot prevent them completely. So if I now fly into a lee area without applying the brakes, at some point it will also collapse. The collapse will perhaps be 1/3 smaller than normal, i.e. than without RAST, but it will still happen. If, on the other hand, I actively apply the brakes, then the leading edge will perhaps dip a little, but otherwise nothing much will happen.

That’s why I also have here 1 – 3 … with active flying, I can actively prevent anything happening. With passive flying, I have to rely on the fact that the glider somehow works.

Resistance to major collapses – 1 to 3:

With active flying – 1:
– the pressure in the rear section can be increased by braking
With passive flying – 3:
– the pressure is not actively increased, major collapses are extremely delayed, but not prevented.


Comparison of the different collapses (superimposed):

  • green: normal flight
  • red: during a disturbance
RAST Swing Paragliders

Here are the valves photographed from inside. We also have a video of this. Note how it is open above and below, the air goes through.

RAST Swing Paragliders

RAST shuts as soon as the pressure below is higher, then it sits against the top surface and bottom surface and effectively closes the rear section. No more air can get out.

RAST Swing Paragliders

Collapses then look like this:

RAST Swing Paragliders

Here you see the typical RAST folding angle. The trailing edge remains completely intact. This is a 14m² glider flown with 100kg all up. And it held, to the extent it ever would.

Here once again graphics to show the lines of collapse:

Red is a conventional glider without RAST – the usual collapse, where the trailing edge collapses back at least to the centre and accordingly the remaining surface area is clearly different. First the red…

Green is a glider with RAST. The green one is collapsed just as far at the front, but at the back RAST keeps the surface open to some extent. And this gives me ⅓ to ½ more surface area than I would have with a collapse on a conventional glider.

RAST Swing Paragliders
RAST Swing Paragliders

(Audience question: Isn’t it necessary for certification that the trailing edge collapses as well?)
Michael: Exactly, that is the biggest problem we have with type-test certification, that the test pilots have to force a collapse in such a way that it goes beyond the trailing edge.
(But the gliders can get certification?) Yes, you just have to use some tricks or ploys. You use both hands, you pull down A and B, use full throttle etc. ….but it is a bit difficult at the moment. For the lower classes, it still goes through the wide cells, if you take time, it empties. So it is easier if you pull down slowly. But at the moment it is difficult with low wing depth, because either it becomes an asymmetric front stall, because you’re turning everything around, or it is much too small because the trailing edge doesn’t go too.

Again, typical, photographed from behind: collapse, RAST stays inflated at the rear.

RAST Swing Paragliders

This is a front stall: This brings us to the next topic – preventing a rosette on a front stall

RAST Swing Paragliders

The worst thing that can happen is a front rosette on a front stall. That means that both wing-tips come forwards, usually they then meet at the front and can then tangle…and then you have a problem!

The front stall should actually happen in such a way that the ears go to the back, that’s the safest configuration. Because then the centre opens first, the ears then follow and inflate again and there is actually no momentum inside. This works best of all if the trailing edge again stays intact.

Here you see RAST from the pilot’s perspective … as he pulled down. Then you see the edge again. At the front it empties nicely, as it should, and the trailing edge simply remains intact.

RAST Swing Paragliders

Front stall … exactly the same … typical folding angle.

RAST Swing Paragliders

At the front everything has gone, dampens the energy, and the trailing edge remains intact.
Same thing as it opens. Now it starts to inflate in the front, at the rear it has of course emptied a little after a while. And the great thing is that it inflates much more quickly at the front, because there’s less volume to fill, than if it were the whole canopy.

RAST Swing Paragliders
RAST Swing Paragliders
RAST Swing Paragliders
RAST Swing Paragliders

This is now a front stall full throttle
… and completely inverted. Here you see how the glider completely somersaults, but the trailing edge still stays intact, for a short time. And the time between the photos is 0 – 1.17 seconds. Here the glider is already partly inflated, the trailing edge is again completely inflated and then it flies again. That means there is less than one second from total shutdown with somersault until the centre at the back is full again.

Once again a front stall, where the trailing edge remains intact:

RAST Swing Paragliders
RAST Swing Paragliders

Asymmetric collapses:
Internal pressure in the excess pressure range (green)
and in the same range with a conventional glider
This is a diagram showing how long it actually takes and what the pressure is inside. We incorporated pressure sensors and observed how the internal pressure in millibars alters in the front and rear sections. This is very interesting, a little laborious to measure. And you see that, in contrast to the conventional structure, where the pressure drops, the pressure increases in the rear section. And that’s why the time it takes until it is inflated again is much shorter.



What we have discussed works reliably and is manageable. “Manageable” means not only for test pilots but also for normal pilots who have some fun testing out the system some time.

The feeling in flight is more direct, harder and much more precise – hard to describe, but for me it is a sort of mix of hang-gliding and paragliding. In particular in extremely turbulent thermals, where the glider somehow no longer wants to turn and I have to really pull down and use weight-shifting …and then it somehow wants to corner and then actually it doesn’t, then gliders with RAST are like this: I simply use the brakes, weight-shift a little and it corners as if it’s running on tracks. I really enjoy flying in thermals and I fly in strong conditions so this has been a huge experience for me. This is what I personally find the best thing about RAST.

Launching in strong winds is easy to control, even in extreme winds. We have also discovered a small problem, that many people find that they are launching in wind in which they can’t fly forward. And then it gets difficult, because then I have to get out, brake and see that I somehow get away.


Discussion about collapses and front stalls:

Certification and safety check:
DakkS/DHV/EN require that the collapse field is achieved:

  • compromises RAST
  • no great advantage on certification / safety check
  • distorted results, discussion needed

Active flying:

  • braking when taking off the pressure is a reliable way to prevent the trailing edge from collapsing
  • loss of altitude is minimal
  • if the deformation energy was very high, the pilot must slowly release the brakes afterwards

RAST is not a miracle cure:

Even if RAST is a very reliable way to prevent major collapses and front stalls, it has limits, as any system does:

  • passive flying in extreme conditions
  • pushing the conditions
  • lack of experience/knowledge on the part of the pilot
  • learning how to handle RAST

… there comes a point when any aircraft reaches its limits….RAST does not compensate for inadequate experience or a lack of knowledge on the pilot’s part.


Certification and safety check

Cost … it uses more materials and requires more work. RAST needs a good deal of strengthening in the corners, because if you properly test it on manoeuvres, now and again the corners can tear. That’s why the corners are all reinforced with special adhesive repair-tape, so that it really holds.

Weight and packing size (meantime solved successfully) … if RAST is on the C-level, then V-ribs are no longer needed. Thus the weight and the packing size are reduced too.
More on performance: performance is always an issue. Everyone wants good performance, without any downsides. RAST has advantages when it comes to performance in certain conditions. The more turbulent the conditions, the bigger the difference. This is easy to explain: in turbulence, everything behind the B-level is flexible, the canopy makes wave movements. RAST stiffens the whole thing similar to the rods in competition gliders in the rear section. So in turbulence I get propulsion from behind and the glider accelerates slightly forwards. And the acceleration brings more height and gives me an advantage.


  • Increased performance depends on the position and type of valves
  • The more turbulent it is, the bigger the difference
  • No difference in calm air
  • Wave movement by the canopy is damped
  • Moving air
RAST Swing Paragliders
RAST Swing Paragliders
RAST Swing Paragliders


  • Various designs tested, we are just at the start:
  • Prevent major collapses in simulation too
  • Specific lines of collapse
  • Multi-RAST
  • Greater aspect ratio

RAST offers a great many possibilities: it can be on A-, B-, C- and D-. It can have several sections, it can go right forward in the centre and to the back on the side. The valves can be arranged differently, certain sections can be completely sealed off, e.g. the centre, so that they can’t collapse at all. And the goal of course would be … (slide above)

So that was a general overview of where we are today. In the future we will certainly see that RAST is refined, adjusted for certification, and series gliders will then be well received on the market.

Keith Brown,
Feb 22, 2018, 5:59 AM