Passive Safety in flying miniwings and speedwings

I have seen some scary collapses on miniwings on social media recently, and heard of some more from pilots directly. Collapses are something most pilots are afraid of and something that does lead to many accidents, but luckily not so much with small wings. Statistically, the biggest risk when flying a small wing is the pilot. Most accidents happen because of pilot error; bad take offs, misjudging proximity flying, fucking up barrel rolls and getting hurt on landings. Most of this can be avoided by being more careful, downsizing more slowly and not pushing the learning curve. When flying small wings, you need to be in your comfort zone. You should always feel you could fly a size smaller. Don’t jump sizes when downsizing. Be aware that it’s one of the most dangerous sports and treat it as such. Your ego is the biggest risk, not a collapse! But let’s talk about collapses now…

I wrote the „Bantam warning“ a while ago, after 3 different customers crashed after launch due to asymmetric collapses, but luckily didn’t get hurt. Jamie Lee, one of the worlds best speedflying pilots, sadly got badly hurt in the same situation. I think this clearly shows a problem we have in our sport of flying small wings; There are very different designs out there that are made for very different things and have different advantages and disadvantages. It’s crucial to understand what sort of miniwing you are flying and understand the risks that come with it.

Nova was very open to discuss my „warning“ and ever since we have had a lot of contact. Of course they questioned it, since they thought the Bantam’s reaction to an asymmetric collapse was pretty gentle. So I went to pull lots of asymmetrics on all sort of miniwings; Little Cloud Spiruline, Minigoose, Advance Pi, Airdesign Susi, Niviuk Kode P, Skywalk Tonic, Ozone Dragonfly, Ozone Rapido, Swing Mirage and some more. I have to agree with Nova, that the Bantam’s reaction to asymmetrics is actually good compared with many others. One of the best reactions has the Airdesign Susi 3, it also got certified as a B at size 16 up to 75kg, also the Niviuk Kode P has a B up to 70kg in size 16. This shows that the certification does partially work for small wings as well. Clearly there are differences, but all small wings turn away quickly if you pull a 75% collapse. It’s really hard to compare, your weight shift has a really big influence and other factors as well. If you just lean a tiny bit to the open side the moment you pull the collapse, they all turn a lot less. It’s super sensitive with these small wings. The worst reactions surprisingly came from real speedwings with monoconvex profiles (airfoils) which are used on skydiving parachutes as well. But exactly these airfoils are known to be very stable and there are not many known accidents with real speedwings due to collapses.

Left side: downforce producing biconvex paraglider profile
Right side: collapse stable skydiving canopy profile

Let me explain these different airfoils a bit here; On the left side we have a regular biconvex paraglider airfoil. The bottom skin also has a curvature. This increases the lift and reduces drag a lot, which results in a lot better glide ratio. A 16m wing with such airfoil and low aspect ratio can still reach a glide ratio of 7-8. By comparison, an Ozone Dragonfly 16 which clearly has the airfoil on the right with the flat bottom skin, only reaches a glide ratio of around 5. But the advantage of the Dragonfly is that it is very collapse-resistant, even when you fly with trims out (accelerated). The most collapse stable wing I have flown is probably the Ozone Fazer 4, it has a very low aspect ratio, a classic very thick monoconvex airfoil. Even while riding it on skis you can almost not collapse it. But it’s glide (which is also known as performance) is rather bad. When it comes to miniwings, we have two main categories of wings here; Small paragliders with biconvex airfoils and big speedwings.

Small paragliders

  • ave a very good glide still
  • make a lot of lift on take off, so easy to get airborne
  • can be EN-Certified (usually C or D)
  • normally come with speedbar system not trimmers
  • Often come with ultralight fabric for Hike and Fly

You can soar them in surprisingly light winds and stronger winds, they are great for Hike & Fly or learning to fly miniwings, as long as you respect their limits and don’t fly in very turbulent air as a beginner. Thanks to their good glide ratio, you can use them on almost all paragliding sites. Thermalling still works for light pilots, but due to the short lines, you feel turbulence a lot and not many pilots enjoy thermalling with them. Even though the glide going straight is amazing, they still sink a lot when doing 360 turns….
It’s also really hard to certify a small paraglider with trimmers, because they stay open after pulling the collapses. That’s why you hardly ever see certified wings with trimmers (apart from tandems, but for a 42m tandem wing 10cm trim travel is like 2cm on a 8m Speedwing…almost nothing).

Examples of small paragliders are: All Little Cloud wings, Gin Griffin, Skywalk Tonic, Advance Pi, Niviuk Kode P, Nova Bantam, Nova Susi Q, Airdesign Susi, Skywalk Spirit, Niviuk Roller, Swing Apus and many more.

Speedwings

  • have a poor glide
  • need more running to get airborne
  • are never EN-Certified
  • Often come with trimmers instead of speedbar system
  • Sink a lot more in turns then small paragliders
  • Are normally more collapse stable then small paragliders
  • Need steeper terrain and more wind for soaring

Big Speedwings are great for getting into speedflying. They feel like a real speedwing. They dive a lot in turns, especially with trims open (accelerated) and then fly more horizontally instead of shooting back up and converting their speed into lift like small paragliders.
Examples of Big Speedwings are; Ozone Dragonfly, Ozone Firefly, Ozone XT 16, Gin Bobcat, Gin Yak, Swing Hybrid, ITV Bip Bip. The Gin Bobcat was the first of this kind.

Using toggles when flying with trims open or speedbar pushed

All paragliders hate it when you fly accelerated (speedbar pushed) and you pull the toggles a little at the same time. That makes them much more likely to collapse. That video of “Partytillimpact” with the Spiruline following the Moustache and taking a full frontal where the Moustache only got shaken, is the best example. That’s why I teach my student’s paragliding is like driving a car; You either push the accelerator or the brake pedal, but never both at the same time. When you push the speedbar, it’s much better to control your wing with your C-Risers (even better via the “b/c bridge” if your glider has one) . I see a lot of pilots still using a little brake to correct their direction or even flying active when using speedbar. That’s really the worst, if you pull the brakes 50% or more when flying on speedbar, wings become more stable again. But a little brake is really the worst when flying on bar!!! Many modern paragliders are also more collapse stable when flying in trim speed and hands up, then pulling 15% brake like most pilots do in turbulent air. (Some schools even call this the “safety position”) Of course when you fly active you must have the brake engaged those 15% or more to “feel” your wing and be connected and also to respond faster. But most beginner pilots I see don’t fly actively anyways and just put 15% brake on and hold on to the risers….that’s not helpful at all. Pull 50% if you want to do this. Flying around with constant light brake pressure reduces your glide ratio and it makes many modern paragliders more likely to collapse.

Most real speedwings with monoconvex airfoils are collapse stable enough that even when you open the trims you can use the toggles to steer and control your wing in turbulent air. But also those wings are most likely to collapse when flying with trims open and pulling a little bit brake. I just got a full frontal on a Ozone Rapido 3 11 like this the other day. (which opened super quick without any hassle) So i recommend flying with rears or the bridge when it gets really turbulent. (anyway it’s better to close the trimmers) If you do fly with the toggles (which helps to stay low in steep terrain like couloirs) and you hit really strong turbulence, best is to pull the brakes hard, like 50%. Then they become more stable again. (or close trimmers, but that takes more time)

It’s a general rule that applies for almost all wings; When flying on speedbar or trims open you lose a lot of stability when pulling down the trailing edge slightly with your toggles. Only when you pull the brakes hard do they become more stable again.

Exceptions

Just because a wing has a monoconvex airfoil doesn’t mean it is safe and uncollapsible, there are for sure some sketchy speedwing design out there! And not every small paraglider is automatically very collapsy. History has shown that some of those big speedwings were rather collapsy when trimmers open and using a little brake, there are quite a few youtube videos showing this. On the other hand the Skywalk Tonic 1 seemed very collapse resistant and the Niviuk Kode P seems the same. Here are some links to some of those collapse videos on big monoconvex speedwings:

https://www.youtube.com/watch?v=xq1Ho4dMjIk

https://www.youtube.com/watch?v=twaNRki3vEk

https://www.youtube.com/watch?v=wKZO9saojVA

Hybrids / Mixed designs

Since pilots want more speed and glide, there are some speedwings that no longer have a completely monoconvex airfoil, but also not a real paraglider airfoil. Examples of these are: Gin Fluid 2, Level Wings Flame, Swing Mirage RS 2. The Fluid 2 has gotten a bad reputation for being collapsy with trims out, but also was a small revolution in terms of speed, roll, glide and energy conversion. The Level Wings Flame and the Mirage RS 2 don’t have a such collapsy reputation, so this shows that there are many more design aspects involved than just the airfoil profile. If it was easy to describe here what makes a wing more stable, manufacturers would have long ago figured it out and we would hardly get collapses anymore. This is very complicated physics and many design aspects come into play here. One thing is fore sure; Modern paragliders are becoming more and more collapse stable, so will miniwings do as well in the future.

https://www.youtube.com/watch?v=AqU91ZnzW0M

Speedflying vs Speedriding wings

Speedriding wings all use monoconvex airfoils. The main difference is they have even less aspect ratio than speedflying wings. This makes them even more collapse resistant. The Mirages and Rapido Series have around 3.8 aspect ratio, the Ozone Fazer series 3.4, the Swing Spitfire series 3.3, the Level Wing Fizz series have 3.5. The Niviuk Skate had even only 2.8! All small paragliders have between 4.4 and 5 normally. More aspect ratio means more efficiency and usually more lift on take off. But it’s just one of many factors. Some pilots use speedriding wings for footlaunchig because they trust them more or they like the steep flight path. Nothing wrong with that, if you can run it and you don’t need more glide.

Reflex wings

Reflex means the airfoil has a S-curve in it’s camber line, meaning towards the trailing edge the camber line is slightly pointing upwards again. The trailing edge works like a spoiler in that case; When the leading edge is pushed down, the spoiler also gets pushed down, forcing the nose up again. (This airfoil picture has a crazy reflex, on paragliders you can’t really see this at all)

This is by no means a new invention, Paramania has brought these airfoils (which had existed for a long time already in other sorts of aviation) into paramotor wings in 1994. Nowadays reflex wings are THE standard in the paramotoring community, since they have huge benefits. The main one is that they are still very collapse resistant at high speeds. In free-flight there are not many wings with true reflex airfoils as far as I know. The Flow Yoti and the new Flare Moustache are the only ones i know. Both are made for coastal soaring. All kites also use reflex airfoils, if not they would always overshoot and frontal when parked at the zenith…
There are very different paramotor reflex designs out there, some pushed to the limits of physics, not very stable anymore to almost uncollapsible ones. There are many factors involved in this stability, if i would fully understand this i would be a designer and not an instructor… Some pilots say reflex is dangerous and should not be used. Probably these are the same people that said leading edge rods are dangerous and should not be used in paragliders when ozone came up with them…For sure every technology has its risk and they have to be found and learned to cope with them. There are many different ways to implement reflex in a paraglider and I’m sure we are only at the beginning of learning how to deal with this. The critics say that reflex wings have a very brutal reaction to collapses, which is surely true for many designs out there. At Flare we believe it’s possible to have a highly stable reflex wing with a gentle collapse behavior close to modern paragliders.

I believe modern paragliders have reached a plateau in performance, where only small progress can still be achieved. You can’t leave the lines away, the pilot is still there creating drag and adding more and more cells only brings a small advantage. But I am convinced that in collapse stability and safety we are nowhere close to the limit yet…there is a lot of room for improvement. Modern designs become more and more collapse resistant and I wouldn’t be surprised to see some kind of reflex airfoils used for this as well in the future.

Angle of attack (AoA) and collapses (also called deflations)

One thing pilots often understand wrong is why a wing collapses (deflates). A collapse happens when the angle of attack (abbreviated AoA) becomes negative, meaning the wind is pushing from above onto the leading edge. The lift gets reversed on biconvex airfoils, creating lift downwards, so the leading edge is sucked down and pushed down at the same time. On monoconvex airfoils (used on most speedwings) the lift doesn’t get reversed, so there is no sucking down, only pushing down on the leading edge. This is what makes them more collapse stable.

Paragliders fly in AoA between 1° to around 25°, some probably even higher. When pushing the speedbar or opening your trimmers, you decrease the AoA, so you are more likely to get a collapse. The more brake you pull, the more you increase the AoA, so the smaller the chance of getting a collapse.
The belief that a wing collapses because it doesn’t have enough pressure inside, is simply wrong. It’s the negative angle of attack that makes it collapse. On paramotor reflex wings, opening the trimmers activates the reflex and makes your wing more stable. They are an exception. All other wings are more likely to collapse when flying on speedbar or with trimmers open. (2-Liner paragliders actually also become more stable when pushing bar)

Why do skydivers get taught to fly fast when it gets bumpy? I think most parachutes are very collapse resistant, so collapses are not the main concern in bumpy air. The main concern is to slam into the ground because you get pushed down by sinking air or suddenly missing headwind without having speed left for a flare. That’s why they teach you to fly fast, to keep your speed so you can flare well even when getting pushed into the ground.

For those who believe flying fast increases your pressure inside the wing, thus reduces collapses; Even if your pressure is higher in the wing, the air also has much more power to deform your wing while flying fast. That would equalize it anyway…two reasons why this theory is wrong!

Some pilots are flying s-turns to keep the wing pressured when hitting turbulence. This isn’t wrong, as long as the turns are not so sharp that you unload your lines for a short moment when changing direction. Putting some g-forces on your wing, increases your wingload which helps for stability. Much better than s-turns are full turns or spirals, but you can’t do them everywhere. I personally much rather fly active than doing turns. If you do get a collapse in a turn, it can be more dynamic then on straight flight.

Speed is your friend

That’s true for proximity flying, for barrel rolls, for take offs and when flying in rain. But speed is not your friend when you get a collapse! The faster you fly, the more aggressive the reaction from your wing will be to an asymmetric collapse. It will turn away more quickly and you are also much more likely to get a bigger collapse than when flying slow.

Using speedbar on small paragliders

Be careful when pushing the speedbar on miniwings. Some of them have a rather long speedbar travel (relative to their size) and fly in a very low AoA, lower than the bigger sizes of those wings. It’s a very dangerous game pushing the speedbar to do proximity flying like I did a lot on the Bantam. That’s why I have only done this is absolut non thermic conditions without any winds. If you wanna fly proximity, it’s much safer on a real speedwing or on a Moustache.

Active flying with speedwings or miniwings

Whenever a speedwing or a miniwing collapses, everyone thinks it’s the wing’s fault. If a pilot in the PWC get’s a collapse, nobody blames the wing… Think about this once! Pilots can prevent 99% of all collapses by active flying, even on speedwings or miniwings. Being part of the miniwing community since the beginning I have learned that most speedwing and miniwing pilots DO NOT FLY ACTIVELY. I think there are many reasons for it;
-Flying proximity and active flying together simply doesn’t work well; You often create lift and leave the ground.
-You have to be even faster than on paragliders with your inputs.
-Many pilots don’t have the skills, they are not even paraglider pilots.
-Many pilots don’t have a good understanding of winds flowing through the mountains and get surprised by turbulence.

As mentioned, proximity and active flying don’t work well together. It’s possible in weak turbulence, but no longer in strong turbulence. That’s why I personally also stop flying proximity when it gets too bumpy.
If you are not flying proximity, flying active on small wings works well, even with the C-Risers you can fly most of them actively even better. If you have sharp reactions, your active flying is very good and well proven on high aspect ratio paragliders, then active flying when it gets bumpy is the best thing for you to prevent collapses on small wings.

If you are only a moderate active flying pilot, I strongly suggest instead of active flying just pull symmetric brake, around 50% of the travel you have on your wing. This will increase the AoA a lot and reduce chances of a collapse a lot! Keep that 50% until it’s no longer bumpy or you are far away from the ground. I think for 80% of all miniwing pilots I know, this is the better option.

However on a Moustache, active flying seems to be the easier and the better option, since you have to “hold” your wing anyways, to not be fully accelerated. When you’re flying your Moustache in bumpy air, make sure your hands can move up and down as much as possible and put a constant pull on the toggles. Even if you are not a very skilled active flying pilot, still try to fly the Moustache actively and quickly pull on those toggles when you feel the pressure on your butt and in the lines dropping. So far there have been no reported bigger collapses of a Moustache yet (apart from the one in the Netherlands recently), but it’s better to be safe than sorry when it gets really bumpy. We think active flying with a Moustache is very intuitive and can be learned to some degree while coastal soaring even.

How to react to an asymmetric collapse?

All asymmetric collapses will recover by themself on miniwings, chances of getting a cravat are very small. The bigger and deeper your collapse is, the more your wing wants to turn towards the collapsed side and it also pitches forward (can shoot in front of you). If you are close to the ground, the wing can turn you into the terrain or make you dive into the ground. That’s the risk of an asymmetric collapse. Best thing to do when you get an asymmetric collapse in my opinion:

  1. Put some brake tension IMMEDIATELY on the open side (some means 30-50%, you really don’t wanna stall it, and the stall point is higher in this case then normal)
  2. Weight shift to the open side
  3. Quickly look up to see how big your collapse is and then look forward again to not hit anything!
  4. You can pump the collapsed side open by pulling the brake hard for a split of a 2nd and release it again. This is not needed, your wing will inflate by itself, but takes more time to do so.

The most important thing is that you put on some brake on the open side as quick as possible. The later you are, the more your wing will turn and dive forward.

Here is an example of a good pilot reaction;
https://www.youtube.com/watch?v=qDdUNzPe7Oo

And here an example of no pilot reaction:
https://www.youtube.com/watch?v=Nwb5liQNfsA

If you think a good reaction to a big asymmetric collapse is easy and this above won’t happen to you; let me tell you my experience in teaching paragliding for 16 years: For most pilots collapses happen very surprisingly, they are not mentally ready for it and the wing turns easily a 90% before they even realize what’s actually happening…only after you had this 5-10 times you learn to react quicker. And that’s on slow paragliders….on miniwings everything happens suuuuper quickly!

A good way to learn to deal with collapses is on the ground:

  1. Try groundhandling in turbulent winds (standing forward and keeping the wing open and in case it collapses keep the heading. Advanced; with trimmers open or speedbar pushed (just tie the string down and make a knot around the biners) Do all of this while facing forward, not backwards!
  2. If you have steady winds ask a friend to pull your A-lines on one side to provoke an asymmetric for you.
  3. Go speedriding on snow, let the lines get slack and the wing collapse while riding in safe terrain without rocks. Don’t go too fast! Deal with the collapses you get and try to keep on going without fucking up your wing.

Danger Zone

Most of us feel safer close to the ground, but obviously this is wrong. In case you get a big asymmetric collapse, your miniwing or speedwing is going to turn really quickly. So quickly that 95% of all miniwing pilots will just get surprised and have zero chance of countersteering and keeping the heading. Whether your miniwing or speedwing will turn 90°, 180°, 270°,360° or more depends on many factors. But most small wings will easily turn a 180° in a second or two, before you realize what’s going on. If you are close to terrain, this is obviously very dangerous. Most miniwings will recover on their own, inflate and fly again after some rotation. The chances of getting a cravat are very small thanks to the low aspect ratio. I don’t think it makes a huge difference if your miniwing has an EN-C, EN-D or no rating at all. They all turn pretty damn quickly anyway. But what makes a huge difference is if you get a 40% or 75% asymmetric collapse and whether you are were pushing the speedbar or not. A 40% collapse with most wings is not a big deal and will reinflate quickly without much turning. On monoconvex speedwings they often open before one can even look up.
To be safe, you have to avoid getting a big collapse while being close to the ground.

So if you know you are taking off into thermic air or some other turbulence, make sure to have enough brake pulled and keep this pulled until you are far away from the ground. Simply doing this will increase your safety a lot already.

Passive safety of Miniwings

I think the certification on paragliders is a great thing. But it’s not designed for miniwings. All small wings tend to turn really quickly after a big asymmetric collapse. Some turn quick, some very quick. I personally think passive safety in miniwings comes mainly from high collapse stability. And I believe there are much bigger differences in collapse stability than there are in how quickly and how far they turn away after a comparable collapse.

The best examples are true speedwings with bad performance and true monoconvex airfoils. Most of them turn very aggressive when you pull an 75% asymmetric collapse. But because it is so unlikely to happen, they are safe wings and flown a lot by many pilots who never fly actively and don’t have much understanding of mountain winds and turbulence.

So here is what I believe; A safe miniwing is a collapse stable miniwing. If it’s certified C or D or not certified can make a difference but collapse resistance is not tested in certification and I think that’s the more important point for the passive safety.

This is my personal opinion and I’m sure some don’t agree with this. Of course the best is to have both; a very collapse resistant wing that only turns gently after a big asymmetric collapse. If I had to choose one or the other, I would go for the collapse resistant wing. But I’m sure in the future both aspects will be much improved on small paragliders.

Frontals on Miniwings

I think frontals are not as dangerous as asymmetrics, since they normally don’t make you turn. If they happen symmetrically, which is a good chance on low aspect ratio wings, they usually open again quickly with not much hassle. The problem is you are more likely to get an asymmetric than a frontal…
If you do get a frontal make sure to go hands up and let the wing recover, even a little bit of brake can make your wing stall after a frontal and shit hits the fan really quickly and you lose control due to the short lines.

Stalls on Miniwings

Most small paragliders and speedwings have very short lines. The shorter the lines, the more difficult it is to fly fullstalls since everything happens even quicker. With short lines, chances to fall into your own wing are higher than on regular wings. So avoid spins and fullstalls at all costs. That’s why you should never break more than 50% when it get’s turbulent. If you’re flying with more than around 70% brake, it can easily happen when entering a strong lift, that your wing will stall already. I’d way rather get a collapse than fullstalling my miniwing in turbulent air.

I’m not an EN-C/D pilot, can i still fly an EN-C or EN-D Miniwing?

There are different opinions out there about this question. My opinion is; Yes, if you are smart enough to avoid collapses close to the ground. Simply putting 50% brake on in turbulence, should keep you safe. EN-D wings normally have an aspect ratio around 6.9, which makes it difficult to fly in turbulent air. You must have really good active flying skills to keep those wings from collapsing. And when they do collapse, chances you end up with a cravat are much higher than on miniwings with aspect ratios around 4.5. You really can’t compare these 2 types of wings with each other. The only thing they have in common is the certification letter “D”.
A miniwing is usually a small beginner wing, a scaled down version of the brand’s A-wing. So you can argue, you are not flying a D wing, you are flying an A-Wing in small. A-wings are usually quite stable, and even more so when highly loaded.

If you want to fly a small wing and not have to worry about collapses too much, your are sure better off with a big speedwing than with a small paraglider.

Lessons to learn

All small wings are potentially very dangerous when you experience asymmetric collapses of more than 50% close to the ground (lets say below 100m). To be safe on small wings, make sure you don’t get more than just a wingtip collapse. Keep in mind, all wings can collapse, probably even a Fazer 4…
Know and understand the differences in the types of miniwings out there. Understand when you are more likely to get a collapse and when not.

Speed is your friend when proximity flying. But speed is not your friend when it comes to collapses!!! Enough AoA is your friend to prevent collapses. Fly slow and high when it get’s bumpy or even better choose to fly another day.

Beni Kälin, Speedflyingschool.com

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