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Are there disadvantages to using parachute fabric to cover an experimental aircraft? So far I observed the following:

  1. I believe I put this fabric in an open place for a year
  2. I found no cracks after a year, approximately
  3. When I tried to set the fabric on fire after a year it didn't catch on fire. It shrunk, but it didn't burn.
  4. I didn't feel any weaknesses or holes in the fabric
  5. I also checked the tension of fabric
  6. In a weight test it up to 10 kg baggage

Now I'm trusting this imported parachute fabric.

I tested three pieces: one original, a second doped in poly varnish, and a third with a paste of mud/soil/sand mixed with poly varnish. The third is best and resists fire best.

Can I use it cover an aircraft?

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    $\begingroup$ Here's a couple of opionions: when you are building an aircraft to which you'll entrust your life, (1) you need better tests on a key component than just "I found some material & a year later it hasn't ripped, so it must be good", and (2) you need more authoritative advice than you can get on an internet message board. Our purpose here is not to provide advice on material we've never seen to be used in a safety critical (i.e. literally life and death) application. If you're building an airplane, get expert advice -- a licensed aircraft mechanic, for instance. $\endgroup$ – Ralph J Mar 30 '18 at 13:40
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    $\begingroup$ I don't think it's possible to answer this question without knowing exactly what the parachute material is. Even then, we don't know what your home-made doping paste is or how it will perform. I think you really need some local, hands-on support on this. I don't know where you are, but EAA or a similar organization could help you if it exists near you. $\endgroup$ – Pondlife Mar 30 '18 at 14:27
  • $\begingroup$ Pondlife , good evening here Karachi Pakistan. Brother here Karachi Pakistan no EAA type organisation or association existing, people are trying itself. But no results found, I've only 5000$ budget for this purpose, I built a RC control panel just for college students they want shown in exhibition. They got third position. Now I want build it with some students $\endgroup$ – user30137 Mar 31 '18 at 11:09
  • $\begingroup$ Why are you mixing dirt with varnish?! $\endgroup$ – Michael Hall Feb 18 at 17:15
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Is there an experimental aircraft association in your country? I would advise you to get into contact with them for better advice.

If you want to know whether this fabric is good enough for covering your airplane, you should plan to perform a load test on the finished airplane. For this you need to know which loads the structure will have to endure. That would be about three or four times the weight of the aircraft on the wings and a proportional amount of load on the tail surfaces. Also consider asymmetrical loading conditions - the photo implies you want to cover a fuselage, and there torsional loads will probably produce the highest stresses.

Another consideration are dynamic and aeroelastic loads. Here it is not only the absolute tensile or compressive strength that counts, but also the stiffness of your structure. The material has an influence, but the way you build the airframe is even more important (think fiber direction - fabric has different properties in different directions). Therefore, I cannot give a good answer without more details.

Lastly, how you finish the fabric will have a lot of influence how long the material will endure in real life. Do you intend to use dope? At least plan to add UV protection coating on top.

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  • $\begingroup$ Peter , good evening here Karachi Pakistan, thanks for suggesting about some serious matter, specially about UV protection of fabric. I'm studying about same. Here Karachi Pakistan all over country no EAA type organisation or association. People trying itself but no results coming. $\endgroup$ – user30137 Mar 31 '18 at 11:04
  • $\begingroup$ @ComprehensiveTracker: I see. Unfortunately, aerospace engineering knowledge in Pakistan focuses around Islamabad, which is quite some distance from Karachi. My advice is: Do a lot of reading and testing before you take to the air. $\endgroup$ – Peter Kämpf Mar 31 '18 at 13:31
  • $\begingroup$ Peter my friend , here Islamabad capital territory of Pakistan , believe nobody have time to give me any kind of attention . Because they don't believe about anyone that who can do this task, I sent a lot of emails my regional aviation authority ( civil aviation authority) and other relevant departments but ( even ) they have no time to give me reply of my email . Big problems. I'm a government school teacher my monthly salary is around 380-$ . But in aviation high salary ( 400-$, 500 or up to 1200-$ ) , that is why reason they have no time for me or any other person. $\endgroup$ – user30137 Mar 31 '18 at 13:44

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