Information on UV Degradation of Aircraft coverings
Traditionally, Microlight sails, or covers, are made from woven polyester sailcloth (commonly known as ‘Dacron’, a DuPont trade name). The strength of this sailcloth degrades over time, especially when exposed to sunlight (due to its high ultraviolet light content). The Betts test was devised – specifically for this kind of sailcloth – in the early 1990s following concern that aircraft were continuing to be flown after their sails / covers had degraded to such an extent that they were no longer safe.