Paraglider Porosity Testing (DIY)

Hello my inquisitive Steemians,

A brief return to all thing paragliding related.

Paragliding is an amazing sport but as with cars and jet-airliners, gliders require regular checks to make sure they are airworthy. A glider service would include inspection of the stitching, material tear resistance (Bettsometer test), line length & strength, pilot related damage and the porosity integrity of the cloth. Due to UV degradation and abrasion, the cloth can become less crispy and more porous. If the material is too porous then the glider will struggle to maintain it's inflated shape in flight which will alter it's flight characteristics and could become dangerous to fly.

Based very closely on Tim Wolf's excellently researched project, I have made my own tester for measuring the porosity of paraglider material. I believe Tim gives his device a tolerance of +/-5% accuracy compared to a commercial porosity meter but I've erred more towards caution on mine with a tolerance of +/- 10%. Different manufacturers have varying minimum readings before declaring a glider unfit for purpose but a general rule of thumb is that any glider that allows a predetermined volume of air to pass through the cloth in 20 seconds or less is a failure. In the first video I talk about the principles of the device and in the 2nd video I test out my old Nova Artax glider and an even older Apco Prima. Even with a +/-10% tolerance, I'm quite happy that the gliders are still airworthy with regards to the porosity.

IMPORTANT: This device is only to give an estimation of the remaining life left in your glider cloth. If you are unsure of your glider's safety or quality then please seek professional servicing or inspection.

This porosity tester is very closely based on the excellent design by Tim Wolf https://vimeo.com/user4524310/porosity

If you found this post entertaining and/or interesting, I would greatly appreciate upvotes and resteems please :)

Many thanks,
Rob.