FAQ

When delivered, sail planes come with a comprehensive manual that, among other important things, also shows the respective polar for the model in question (polar = a curve in the coordinate system / horizontal speed is entered on the X-axis and sink rates on the Y-axis). In the paragliding world there are a significant number of pilots who demand the same for their wings – on average we receive one or two emails a week asking for polars for one model or another. Our answer is always the same: “They don't exist and they won't.” Why can't we provide all the technology-loving UP pilots with this data, for example to feed the flight instruments with it? The answer is not a simple one, so we would like to explain the problem.

Theoretical calculation of performance data

A paraglider is no longer in its original form after the first inflation. The profile chosen by the designer is sewn into the canopy with the profile ribs. However, the cell walls are only an infinitely small part of the entire wing; the largest part is the sail panels of the upper and lower sails. These inflate due to the higher internal pressure prevailing there. Due to the pressure distribution, this inflation is not precisely calculable due to the “soft” nature of the wing.

The cell walls sit in recesses in the inflated upper and lower sail panels. If you try to include this inflation in the flow simulation, you get different simulation results depending on the calculation model. With only a small change in the inflation effect that we add to the model, these vary greatly. This in turn means that all simulations are quite inaccurate and the real values change over the life cycle of the wing due to the aging of the paraglider fabric.

We therefore have the paradoxical situation that the known profile-giving parts (cell walls) are hidden territory in the sense of flow simulations and calculations. In the center of the cell, we can predict the airflow with the necessary degree of accuracy, but due to the inflation of the cell, we cannot model it sufficiently. The more cells we add to the canopy design, the more accurately the filled canopy matches the desired profile design. However, more cells result in higher manufacturing costs, higher weight and also poorer canopy behavior after a collapse. And all this before we have incorporated turbulence into the calculation.

Paragliders are “soft” flying machines made of fabric that are inflated by an infinitesimally small pressure difference. They are therefore not as susceptible to the laws of physics as flying machines made of other materials. A paraglider is constantly being “bounced around” in the air and every small movement thus changes the profile on a small and large scale. This means that the profile currently flying through the air never exactly matches the profile selected by the designer.

A significant part of the wing design is aimed at reducing or at least controlling the deformation of the profile when the wing is moving through real air (and not through a modeled laminar airflow on the screen). In UP wings, the horizontal tapes on the A and B levels in particular ensure a stable canopy along the span. Mini-ribs (small additional ribs along the trailing edge) ensure that the trailing edge does not bend when the internal pressure changes at different angles of attack. A small side note: our NGA (New Generation Airfoil), which we use on all performance wings, also smoothes out these pressure differences, which significantly reduces the phenomenon of the rear edge being shortened by the cells bulging and thus the deformation of the canopy geometry in the rear area.

In some cases, the soft, yielding property of the canopy can even be used to our advantage. Especially with lower-classified canopies, the area around the leading edge is designed to be softer in order to dampen the energy that the canopy develops when, for example, shooting forward when flying out of a thermal. This effectively prevents further descent and a possible collapse.

We are often asked why our gliders (despite their high aspect ratio) react so well to collapses and are even very collapse-resistant. The answer to this lies in precisely this characteristic: the damping effect of a soft, yielding canopy.

All this information underpins our actual intention: why we do not provide detailed performance data for our glider models. We have emphasized the technical challenge of computer-based data generation, but there is more to it than that.

Statistical determination of performance data

Another conceivable way to generate performance data with sufficient accuracy would be to collect data during countless real flights in calm air. This would be a viable approach for pilots who need data for the final glide calculator of their GPS variometer. To do this, the pilot would have to create a data table on a cloudy, early morning without wind at a sufficiently high launch site by determining the sink rate as a function of the glide rate. The more data points collected, the more accurate the resulting polar curve* will be – FOR THE GLIDER/HARNESS COMBINATION USED AND THE RESPECTIVE ALTITUDE AT WHICH THE DATA WAS COLLECTED! These data are in turn unusable for a friend who flies the same wing but uses a different harness or adjusts it differently, and they are significantly different if the data are collected at different altitudes with the same configuration. This is one of the reasons why we do not use this method to determine absolute performance data, since the determined polar is only relevant for the individual wing, and only at the altitude at which the data was generated.

Market mechanisms

Typically, the model life cycle of a wing is 2 to 4 years. If a wing manufacturer uses performance data as a sales argument, they will quickly notice that the market expects a performance improvement of about 0.5 in the glide ratio compared to the previous model. However, such an increase is completely unrealistic within a period of 2 to 4 years. Over a period of 10-15 years, this manufacturer would publish increasingly unrealistic figures, to the detriment of the credibility of the entire industry and especially for the individual manufacturer concerned. This manufacturer is only successful until the market realizes the bluff. The result then varies from mild annoyance to expensive misdirection.

Fortunately, due to the special nature of wing design, a new model can mean a giant leap forward without being revealed by a computer-modeled or experimentally measured data diagram. Simply by being both safer and easier to fly in turbulence, as well as by improving the conversion of energy into height in turbulent air and also improving climbing performance in weak thermals. These characteristics are not and cannot be measured objectively, but experienced pilots will notice the glider's improved performance shortly after take-off and will be able to use it much better than by increasing the calculated glide ratio by 0.5.

Conclusion

There are numerous good reasons for NOT publishing absolute performance data. If these are determined scientifically, e.g. with computer simulations, they are based on assumptions that cannot be completely modeled. If these are determined by flight tests, they are only relevant for the respective wing/harness combination during the test. Thus, both methods are fairly inaccurate. We want to maintain the trust of our customers, which is why we do not publish this data.

PS: There is nothing like a test flight. The most important thing is how you feel. Ultimately, you will only get the maximum performance out of a paraglider if you feel completely comfortable under the wing.

UP currently has two EN/LTF C certified paragliders: KAILASH and TRANGO X. These differ significantly, because the KAILASH is a miniwing, built as a descent aid and for dynamic flight maneuvers, while the TRANGO X is a 2.5-liner for long-distance flights. You can find more details about both models on the respective product pages.

At the moment there are five UP paraglider models certified EN/LTF B: MAKALU 5, KIBO X, LHOTSE X, SUMMIT X and KANGRI X. All those with “X” are 2.5-liners - at UP, the “X” stands for “Cross” and thus for hybrid. We define MAKALU 5 as a low-B, KIBO X and LHOTSE X as mid-range B, and SUMMIT X and KANGRI X as high-B. LHOTSE X and KANGRI X are particularly light and packable. These two models also come with the ideal CompressSmart pack sack for hike & fly. You can find all the details about the individual models (features, technical data, sizes, etc.) on the respective product pages.

Our three A-class gliders, RIMO 2, MANA 2 and DENA, can be briefly summarized as follows: the RIMO 2 is ideal for training and for all beginners who want a robust yet agile wing. If you appreciate lightweight materials and a reduced pack size, you will find exactly that in the MANA 2. For those looking for a high-A, we have our DENA - here you will find as much performance as the A-class allows. You can read the details of all three models on the individual product pages.

There are several reasons why the material of the lines plays an important role:

• Different line materials have different breaking loads, even with the same diameter.
• Some materials age faster than others, but may have other advantages that make them desirable.
• Sheathed lines tend to last longer because of the thin sheath woven around the line core, but they are also thicker for the same breaking load, since part of their diameter consists of the sheath, which only adds thickness but no strength.

Line drag is a large part of the wing's overall (unwanted) drag, and reducing the number of lines used and their diameter is a reliable way to improve performance.

These materials/lines are available:

Sheathed Dyneema

From the outside, all sheathed lines look the same, as we only see the sheath and not the core of the line. But when a sheathed Dyneema line is cut or breaks, we see that the core is white and non-woven (sheathed lines are extruded, then the sheath is woven over the extruded core).

The picture shows two damaged lines, both of the sheathed Dyneema variety, and the white core. The line on the right is a bit tricky; it feels lumpy and has been damaged by excessive stretching, but a quick visual inspection cannot/will not notice the damage, yet both lines must be replaced before the next flight.

Sheathed Aramid/Kevlar

Looks the same as above if the core is not visible. Once you see the core, you can tell it is light brown in color and made of non-woven aramid fibers. The color gives it away: light brown. You can usually see the exposed core at the end of a line where it is sewn into a loop. If the core looks “dirty”, it is most likely aramid.

Unsheathed Dyneema

Is white until it is dyed. However, it is unusual to see completely white unsheathed lines on a paraglider, except on older Axis or MAC Para competition wings. Dyneema is easy to color, and most manufacturers use lines that are colored by the line supplier, often in red. The line is woven and has a smooth, (slippery) appearance and feel.

Uncovered aramid/Kevlar

These lines are not as easy to color, so they are usually used in their natural light brown color. These lines are woven and have a much less smooth look and feel. They quickly look quite old and frayed when exposed to the rigors of a less than perfect launch area. In the picture below, the left line is unsheathed aramid/Technora, the center one is sheathed (either aramid or Dyneema), and the right one is unsheathed Dyneema.

Properties of the different line materials

If we focus strictly on the technical specifications as given by the line manufacturers, unsheathed Dyneema lines are the superior material from almost every angle; they are stronger than their sheathed or unsheathed Aramid/Kevlar counterparts of the same diameter, and they are also stronger than sheathed Dyneema lines, due to #3 in the list above. They are even comparatively insensitive to the effects of UV radiation (sunlight), they are not easily damaged and they survive the standard “5000-cycle” bending test, in which a line is mounted in a test stand and then subjected to five thousand 180º bends, very well. They are even dimensionally stable in length when heavily loaded, i.e. they do not stretch (much) under load.

At the opposite end of the spectrum, we have unsheathed aramid/Kevlar lines. As mentioned, they are not as strong, but to make matters worse, they tend to degrade comparatively quickly when exposed to UV radiation, they fray more easily when physically abraded, and they lose worrying amounts of (strength) when subjected to the “5000-cycle” flex test. Aramid/Kevlar lines stretch a little more than Dyneema under load and are better at retaining their new length when the load is removed.

somewhere in between are the laminated lines, which are made from either Dyneema or Aramid/Kevlar. Their main advantage is that they are less prone to damage from physical abrasion and UV radiation, but they will always be thicker for the same breaking load (bad for performance). Some pilots find that they are less prone to tangling and knotting, which is a good argument for using them on beginner and intermediate wings.

Based on what we have learned so far, choosing the right lines seems simple – use unsheathed Dyneema for most applications, and maybe some sheathed Dyneema for school wings. Unfortunately, things are not quite that simple.

First of all, we have to realize that while Dyneema is dimensionally stable under load, it does tend to shrink under certain circumstances, for example when exposed to temperatures above about 70 degrees Celsius. Initially, all lines tend to shrink evenly – but as soon as a wing with shrunk lines is launched for the next flight, the A and B lines, which carry much more weight than the C lines, return to their original length, while the C lines remain too short and bring the wing out of its certified trim. Temperatures in this range may sound unlikely, but the fact is that if you leave your/a pilot's wing in the boot of a car on hot, sunny days, or if you lay out your/the pilot's wing on the hot sand of Iquique or Sossusvlei, the temperature will soon be much higher than 70 degrees. So not only for the Dyneema lines, but also for the cloth of the canopy, you should never leave the wing in the trunk of the car, and you should try to limit the exposure in the hot desert sand of tropical regions.

To make things even more interesting: The only way to know for sure if your wing is trimmed is to measure it, and preferably with a professional setup (laser measuring device, 5 kg load on each line, etc.) – we can suspect that something is wrong, for example, if the wing no longer inflates nicely or fills with air or if it climbs less efficiently than before, but to really KNOW , we have to send the wing for a check.

Aramid/Kevlar lines and their relative disadvantages compared to Dyneema have already been described – but unlike Dyneema, it is very easy to see on an unsheathed Aramid/Kevlar line when it is worn, and although they stretch and are not as strong, at least they do not shrink.

All this means that the designer has to take a few things into account when choosing which lines to use, such as:

• Which pilot segment is it intended for? A wing designed for very advanced pilots can legitimately be equipped with lines that require a little more attention, provided they offer significant performance advantages (Dyneema...)
• Is performance at any cost more important than longevity? That is, will the intended pilot profile ever consider sending the wing in for a check, or will it expect to remain airworthy for the entire lifespan of the canopy without further attention? The latter scenario argues for sheathed Aramid/Kevlar lines, which don't shrink and are resistant to UV damage due to the sheathing, but actually these lines should also be checked from time to time, not least because of their inherent problems with the “5000-cycle” bending test and similar in real life...

One way to enjoy the cake is to use sheathed aramid/Kevlar for the thicker, lower line levels and Dyneema for everything above the first ramification. This is because the total length of the shorter gallery lines is not affected as much by, say, 0.5 percent shrinkage as the longer lower lines, and also because the thick main lines are quite oversized on many wings anyway. But this solution assumes that you are looking for a compromise anyway, whereas with performance wings we generally aim for the lowest possible (parasitic/unwanted) drag, and then we are back to unsheathed Dyneema...

It would be tempting to think that we could get around the paradox by using slightly stronger Dyneema lines for the main lines and normal, thin Dyneema for the gallery – after all, this would mean that we would have the best of both worlds in terms of most of our parameters, right? Wrong! The problem with Dyneema is not strength, but shrinkage, and that occurs regardless of line diameter.

The conclusion is that as long as we are so hell-bent on performance gains with each new model incarnation, we need to learn to live with the few drawbacks that come with using Dyneema lines – other line materials have their place for certain applications, but on performance models, at the time of writing, there is simply no reasonable alternative to Dyneema. That said, for performance pilots flying a performance wing, it is good practice to have the lines checked from time to time (as per the manual) and to be alert to subtle changes in the wing's launch and in-flight characteristics. The advantages of careful handling of your equipment are higher performance AND higher passive safety. Not least because Dyneema is much stronger and stays much stronger than any other line material currently used in paragliders.

Generally speaking, the technical data for each model indicate the approved weight ranges. You can find the technical data on the respective product pages. The “sweet spot” in terms of pilot weight/glider size depends a little on personal preference and the planned use. Examples: vol-biv flying with a lot or a little luggage? Dynamic or normal flight behavior preferred?

UP designer Franta Pavlousek has some tips for choosing the ideal size:

“If you are in the middle third of a weight range for an UP wing, then you have already found the right size. If you are between two sizes and are wondering whether you should fly the smaller size in the upper third or the larger size in the lower third, then it's best to proceed as follows: If you are an experienced pilot and have always flown in the lower third or upper third, you should also choose your UP wing accordingly. If you generally prefer to fly with more weight than less, you should choose the smaller size. If you prefer a larger surface area, there is no problem in flying the larger size. It's really just a matter of preference. The wing will still fly fast and have precise handling."

Even if you do a lot of flying in flat terrain, you will probably be right to choose the larger wing. Those moving up in class are also better off choosing the larger size. Then the jump, for example from EN-B to EN-C, is not quite so huge.

As the UP development team, it is our philosophy to maintain all the features that pilots love about one of our glider series in the next generation – supplemented and improved by our input. This makes our existing customers happy and therefore makes us happy too. If you fly an UP series, you can be sure that the successor will give you the same handling that you are used to.

IMPORTANT: If you have been flying an older UP generation wing (up to and including the KANTEGA XC, SUMMIT XC, TRANGO XC, EDGE or any of the TARGA models) and you want crisper, more accurate handling, then it is best to fly the new model at the upper end of the weight range. If you want to get closer to the feel of your old model, you should go up a size.

At the moment, none of our models are certified for use with a motor. We will be happy to let you know when this is available – subscribe to our newsletter to do so.

The CompressSmart is available in two sizes (S, M) and weighs less than 200g in the small size. Size S is blue and size M is green.

Here is the CompressSmart included in the scope of deilvery:

Alternatively, the CompressSmart also fits here:

The same applies to the predecessor models of the “LHOTSE”, “KANGRI” and “MANA” series.

Whether it is a model with or without rods, we recommend not to store the leading edge in a tightly packed bag if possible. It's fine for the journey to the take-off site or back home, but you should avoid storing it like this for long periods. Otherwise, no special packing technique is required and you can use any inner bag you like. We supply our respective favorite with our paragliders – although these are, of course, designed for different models/uses. (For example, the CompressSmart compression bag for our light wings.) If additional model-specific recommendations are appropriate, you will find them in the manual.

C-steering using the C-handles is an additional option for compensating for the pitching movements of the paraglider, especially in accelerated flight. Used correctly, it enables more efficient flying in turbulent air. The operating forces are so low that even during long-distance flights, there is no sign of fatigue. Asymmetric corrections, e.g. for changes of direction, are also possible. If you don't want to use the C-handles despite all the advantages, you can simply remove them. By the way: For the sake of simplicity, we also refer to our 2-line and 2.5-line gliders as having C-handles and C-control, although the line levels are different from the classic A-B-C. The term “C-handles” has become generally established independently of this.

The certified weight range defines the legal limits of the take-off weight. Since the legally permissible weight range is sometimes large, there is within that also the manufacturer's recommended weight range. In our experience, the recommended weight range represents the ideal combination of climb, stability and speed – the best conditions for efficient XC flights.

UV radiation is probably the biggest factor when it comes to the lifespan of a paraglider. So it's best not to leave your equipment in the sun unnecessarily. When carrying, you can reduce the stress on the material by making sure that the canopy does not drag across the ground. Sand and dust can act like sandpaper, so it helps to avoid them. Should you ever need to remove stains, please use only water and no cleaning agents/brushes. When it comes to storage, we recommend: dry, loosely packed, well ventilated and dark.

Snow-Pins make it easier to launch on steep (snow-covered) terrain because they allow you to easily fix the canopy to the ground. This means that the paraglider can be laid out neatly and you don't have to scramble around to rearrange it just because a small gust of wind has passed or the cloth slips on a smooth surface of snow. When you take off, the pins are simply pulled out and fly down into the valley attached to their loops. If any get lost on the way, it's not a problem: the Snow-Pins are made of wood and are therefore biodegradable. Don't forget to remove the pins from the glider before packing it up to avoid damaging the fabric. You can find detailed instructions on how to use the Snow-Pins correctly in the manual.