When a glider ages, it is the leading edge of the top surface that ages faster than any other part of the wing. This is because of two reasons. Firstly it is this place that receives twice the UV exposure compared to other surfaces of the wing. The bottom surface gets exposed to the sun when the glider is laid out on the ground. The top surface gets exposed to UV in flight, only the top surface close to the leading edge where the open is actually gets exposed to UV in both situations. This is one reason why it gets worn out quicker.

The other reason that the leading edge of the top surface gets worn out faster than the rest of the wing is that the there is the most tension in this area, and also the biggest pressure difference across the cloth caused by aerodynamic forces which also contributes to the wear of the cloth in this zone. Gelvenor cloth has proven its self to be one of the very best cloths for long life. This is because it is silicon coated, and is also heavier than most other cloths used to make paragliders, weighing in at a heafty 50gm/sq m. It is not suprising that Gelvenor has gained an excellent reputation for long life in the paragliding industry. However the increased weight of Gelvenor means that the glider becomes heavier, leading to more inertia in the wing and sluggish launch characteristics, not to mention that fact that you have to carry that extra weight around on your back as well. For the last 18 months we have been testing the concept of mixing cloths on the top surface, putting Gelvenor on the first stripe of the leading edge and 39 gm/m, Porcher 9017 E38A on the rest of the top surface.

The objective was to make a glider that lasts just as long as a 100% Gelvenor wing, but with the lighter overall weight. The result is the Hybrid top surface. The Mustang M for example weights in at a mere 5.6kg, approaching the weight of a mountain glider, but with a sail that is without compromise in terms of life expectancy or due to its innovative hybrid design. We use this special sail on all our gliders of 2005.