Fabric Punch Test

[Carl Ellis]

With modern fabrics and methods, is this still a valid test to perform at annual time?

Is a punch test something that should be done at every annual? Is it required?

What does it actually tell us? Is it go, no-go, or is there a continuum?

How is it performed?

- Carl -

[Robert Lees]

Re: Fabric Punch Test

I don't believe the punch test (e.g. Maule test) actually has any legal standing. An IA might use it to base an opinion as to the serviceability of the fabric, but that is all.

Would be willing to be stood corrected, however.

Rob

[Forrest Barber]

Re: Fabric Punch Test

Basis for opinion is correct. In the old days we used to pull a 1 in. strip of fabric to destruction with a pull scale. THEN the Seyboth tester came out which did put a hole in the fabric for sure with a graduated rod out the top for use to indicate condition of the fabric. The test pounds are still in the FARS . the new Dacron fabric, etc. usually has the finish go before the fabric drops down to an unacceptable strength . Kind of like having great teeth but the gums are shot!!! I will elaborate on this at the fly-in... Soooo an IA with an experience does not "punch" test each year. The Maule tester if used correctly does not put a hole into the fabric unless it is very low testing.

[alwaysoar]

Re: Fabric Punch Test

Also, I heard That the Maule tester will actually test at an unrealistically low number because the weave on ceconite will spread thus allowing the Maule to go through. True?

[Carl Ellis]

Re: Fabric Punch Test

So this begs the question:

Is this a valid and conclusive test (when using the Maule tester). Would you insist on it being performed if you were purchasing an airplane?

I assume that it may require fixing up areas of the fabric that the tester applied pressure to, yes?

- Carl -

[alwaysoar]

Re: Fabric Punch Test

The ceconite failed on a J-3 I owned once. There was not enough UV (silver) protection, and the sun got to it. This was Vermont where we don't see much sun. Modern dacron cover is life time only if it's done properly. If I were buying a plane today, I would look up through the inspection plates in the wings to see if I could see daylight, and back into the empenage for the same reason. I would check especially closely along the edges of the surface tapes because if they are not shrunk properly during covering, the sun will do the job exposing a few thousands of unprotected fabric to the sun. If you are in doubt after this inspection; that is, the UV protection does not seem to be keeping the sun out, do a Maule test. You don't have to go much beyond the minimum standard for linen (46 ibs I think) to satisfy yourself that the fabric is good. So, even though a fabric test on dacron is not required at annual, and it is not the be all, end all of tests, I would still insist on a test if I were buying an airplane. The tester won't go through good fabric at the minimum (check AC 43-13 for the exact number of Lbs). If the seller says no, look elsewhere--

[lktiller]

Re: Fabric Punch Test

Ring-worming will break the UV protection. Good to include in walk-around checklist to look for breaks in paint.

I didn't buy a t-craft several years ago because of severe ring-worming. And peeling paint, and the 'owner' was due to report to prison, and he didn't have a pilot's license, or a bill of sale, no registration, no annual, no logs...... And so it goes.