All you need to know about gliders
If you weigh less than 60 kg, then you've probably already been called a "small flying weight", and it's likely that you sometimes have trouble finding a glider that fits you. What's more, in the course of a paragliding pilot 's life, who hasn't heard that smaller gliders are less efficient than others?
Indeed, within the same glider range and with the same wing loading, the paraglider with the smallest surface area will tend to behave differently from the larger size. Where do these differences in behavior come from, and how can they be explained by design ? In this article, we'll take a closer look at this issue, which concerns many pilots.
Big Size Vs Small Size: What Are The Differences Between design ?
To understand where the differences in behavior between sizes of the same reference come from, glider, we need to look at the design paragliders.
When creating a new line of wings, designers begin by developing the wing in a single size. This size is generally chosen to match the test pilots’ “ all-up weight ” (all-up weight), so that they can test the prototypes without adding weight and thus avoid skewing the flying experience. Since test pilots rarely have a “ all-up weight ” that corresponds to the smallest wings, the larger sizes are developed first and then scaled down to smaller sizes.
After completing the development of the first size, the next step is to apply a homothety* to obtain a working basis for the other sizes. However, this is not enough to guarantee the performance of each glider. It is therefore necessary to individually adapt the characteristics and dimensions of each size before validating the production of the entire range.
*Homothety: Homothety is a geometric transformation that enlarges or reduces a figure while maintaining its shape. This means that the dimensions of the original figure are multiplied by a constant factor to obtain the new figure, which is a similar image of the original. In other words, homothety changes the size of a figure without distorting it.
However, perfect homogeneity should reduce not only the dimensions of the structure and its geometry, but also the diameter of the rods and rods. lines used, or the thickness of the fabric that makes up the Airfoil. However, this is not the case in reality: the size of the materials, whether their diameter or thickness, will remain unchanged regardless of the size of the material. glider on which the designers are working.
It is therefore necessary to rework and modify the homothety achieved upstream so that the characteristics of theglider can correspond to the materials that remain common to the entire range. Therefore, we can already conclude that two sizes, although belonging to the same range, will never be perfectly identical in terms of structure and pure construction.
What are the consequences of these differences design ?
The materials used have a significant impact on the behavior of small paraglider due to their weight. Indeed, given that the diameter of a Rush remains constant whatever the size of the glider, its contribution to the total weight is more significant on small gliders than on large ones. This principle also applies to other components such as straps, lines and Fabrics. So, despite the reduction in glider size, the weight of materials has a proportionally greater influence on smaller gliders than on larger ones.
This additional weight influences the inertia of theglider, modifying its behavior in relation to the size initially designed by the designers. This inertia will tend to make theglider more reactive, with more energy in its movements.
In order to avoid a glider that "attacks" too much, designers have to modify the pitch settings to pitch up the ends ofglider and counterbalance this effect.
By slightly increasing the angle of incidence of the stabilos, the more energetic movements of theglider are smoothed out by a less biting Airfoil and the reopening of the glider is facilitated. On the other hand, this also creates an additional drag net, slightly degrading the performance of theglider.
To sum up, in order to guarantee a similar level of passive safety across the range, designers sometimes have to make concessions on performance. Note that this difference is minute and almost negligible on progression gliders . On the other hand, it's much more obvious at High level, on CCC-type competition gliders , where every detail can make a difference. This is the main reason why smaller gliders are reputed to be slower and less efficient than their bigger sisters.
Testing and certification: what are the consequences?
In addition to design, several other factors come into play when developing and launching glider for smaller pilots.
Designers face another challenge that may lead them to propose all-up weight ranges greater than what a wing can actually handle: certification and load testing.
all-up weight To understand this point, it’s important to know that each wing size is certified separately from the rest of the range (which is why you’ll find a different certification report for each size). During the certification process, a wing is tested twice: once at the mini all-up weight , and once at the max .
This is where our problem comes in: if the test pilot’s all-up weight is too light to reach the maximum all-up weight , he simply needs to add weight to reach the upper end of the range. On the other hand, if he is too heavy for the minimum all-up weight , there is nothing he can do about it, and a lighter pilot must be found to perform the test.
To certify a wing with a very low glide all-up weight , a very light pilot with the necessary flying skills must be available to put the wing through the certification tests. As you can imagine, such a pilot is not always available to test the smaller wing sizes.
Finally, let's take a look at the load test. Unlike homologation, where each size is tested individually, only the largest size in the range is tested under load. Smaller sizes are then designed with the same level of resistance, even if the stresses and strains they will encounter are lower than those of the largest size.
As a result, the designer ensures that the entire range complies with the load test, but the smallest sizes are significantly oversized. This is very reassuring, but it also means extra weight for the smaller sizes. As we saw earlier, extra weight means extra inertia, which again brings us to the consequences described before : more aggressive behavior, twisting of the glider tips, extra drag and potentially degraded performance.
The evolution of the community paragliding pilot
Finally, we'd like to address a point that has more to do with the evolution of paraglider and Airfoil than with design .
These days, there are more smaller-statured paragliders than before, partly due to the increase in the number of women participating in the sport. In fact, while women (who tend to be smaller in stature than men) now account for about 1 in 6 pilots, their numbers were much lower just a few years ago. In addition, paragliding has become more accessible thanks to technological innovations, and paragliders are starting to fly at a younger age, which means they are also lighter. For all these reasons, market demand for small- all-up weight s is steadily increasing.
In the past, manufacturers had little incentive to spend a lot of time developing small wing sizes, since the market for them was particularly limited. But now, this market is growing, and the demand for suitable equipment is increasing. That is why designers are paying closer attention to their product lines to offer a all-up weight ranges that go lower than before. This market expansion is also prompting designers to focus more on the challenges associated with designing small wings and to find solutions that ensure performance comparable to that of larger sizes. In short, the industry is evolving to meet the needs of pilots.
In conclusion
You now have all the keys you need to understand the differences that can exist between two sizes in the same range, and what justifies them. Whether for reasons of passive safety or to adapt to market demand, the way in which small gliders are designed is constantly evolving, and is a hot topic in design offices.
However, it’s essential to keep one key point in mind: always choose your paraglider based on the weight range all-up weight recommended by the manufacturer. It’s not recommended to choose a larger wing and add weight to fly below that range in order to get a higher-performance wing. The best wing will always be the one that matches your size.
For lighter pilots reading this article, we invite you to discover the wing that meets all these design challenges: the LEAF3 Light XXS, an EN-B wing suitable for pilots weighing as little as 45 kg ( all-up weight), is just as fun and high-performing as its bigger siblings. Its handling remains playful and intuitive, helping you progress after you’ve moved on from your training wing.
For all other sizes, we hope you'll find what you're looking for in the Supair gliders range, so you can fly a paraglider that's just like you.
LEAF 3 Light XXS - designed for very light weights!
