Today I decided to test the wing fabric on my plane. The fabric is made of dacron sail fabric. Polyester fabric. It is strong and light. But it is sensitive to UV deteration from the sun. The wing is painted whit a paint mixed whit aluminium paste. Still it ages, depending on how many hours it has been in the sun.
In my bible, Ac43-13, it is described how to test the fabric. I had to cut out a piece of the top wing, clean the test piece, and clamp it in the ends. Then I used some weights and started to load the fabric until it broke.
One piece from the top of the wing and one from the bottom. The top piece is weakened, but it has to be able to take a load of 35lb/inch (15kg/25,4mm) to pass the test.
It did pass the test. I was able to load 19kg before it snapped of.
And here it is breaking on 19kg load.
I can fly safe with these sails. I just need to repair the holes.
Jag är ett sätt att tänka.