Help researching AD 93-10-06

[mhorowit]

Before I comment to the FAA on AD 2007-16-14 I'd like to provide a reference to "the Piper AD that requires a punch test". Googling around, I see AD 93-10-06 mentioned, but reading that AD and the one which supercedes it (AD 99-01-05) I don't see the word 'punch'.

If someone has the time, could I get some help finding the Piper AD which say a punch test is an OK way to test struts? Thanks, MikeH

[barnstmr]

Re: Help researching AD 93-10-06

Punch test is actually just a slang term. The test is using a Maule fabric tester. I think the FAA is scared of this test because they must believe it is like a "center punch" that would mar the surface of the part. The FAA MIDO inspector I spoke with on this was afraid of the "punch mark" leaving a stress riser. His thinking is wrong. The Maule tester in fact does not mar the surface. The Maule tester is designed with a spring scale that is calibrated to indicate pounds. It has a ball-shaped end that will not harm the surface of steel struts. The fabric test criteria was developed as a way to tell if Grade A cotton was rotten. If the fabric would not "punch" 50 pounds or so (depending on the aircraft Vne), then the fabric was considered unairworthy. This criteria is still applicable, however the synthetic fabrics rarely fail the test. So once again, the all-knowledgeable FAA is right and the lessons learned from aviation history are out the window.

[Ragwing nut]

Re: Help researching AD 93-10-06

Punch test is actually just a slang term. The test is using a Maule fabric tester. I think the FAA is scared of this test because they must believe it is like a "center punch" that would mar the surface of the part. The FAA MIDO inspector I spoke with on this was afraid of the "punch mark" leaving a stress riser. His thinking is wrong. The Maule tester in fact does not mar the surface. The Maule tester is designed with a spring scale that is calibrated to indicate pounds. It has a ball-shaped end that will not harm the surface of steel struts. The fabric test criteria was developed as a way to tell if Grade A cotton was rotten. If the fabric would not "punch" 50 pounds or so (depending on the aircraft Vne), then the fabric was considered unairworthy. This criteria is still applicable, however the synthetic fabrics rarely fail the test. So once again, the all-knowledgeable FAA is right and the lessons learned from aviation history are out the window.

To further emphasize his stupidity, if you don't remove the exterior paint, you can't check for exterior corrosion that might be covered up by the paint itself. If they are going to make us inspect these struts, then it needs to be done correctly and thoroughly.

Mike

[dmcneil]

Re: Help researching AD 93-10-06

Before I comment to the FAA on AD 2007-16-14 I'd like to provide a reference to "the Piper AD that requires a punch test". Googling around, I see AD 93-10-06 mentioned, but reading that AD and the one which supercedes it (AD 99-01-05) I don't see the word 'punch'.

If someone has the time, could I get some help finding the Piper AD which say a punch test is an OK way to test struts? Thanks, MikeH

Hi Mike,

The Piper AD (99-01-05) only mentions the Maule fabric tester method by reference to the Piper SB. The Piper SB 528D details the procedure to use for the corrosion inspection. I posted a link to the SB in a prior post but here it is again: Piper SB 528D

Dan McNeill

[mhorowit]

Re: Help researching AD 93-10-06

Hi Mike,

The Piper AD (99-01-05) only mentions the Maule fabric tester method by reference to the Piper SB. The Piper SB 528D details the procedure to use for the corrosion inspection. I posted a link to the SB in a prior post but here it is again: Piper SB 528D

Dan McNeill

Thanks Dan, that's the reference - MikeH

[hangarb7]

Re: Help researching AD 93-10-06

So what does everyone think the chance is that this will end up to be some version of Maule test? I mean, did the Piper AD start the way the Taylorcraft Strut AD started?

Is that what one of our comments should be to the FAA?

I am afraid of going fully forward and just buying a set of sealed struts (get on the waiting list) and then find that it was relaxed and also there would be a further AD with the structure on the fuselage.

I am thinking of just waiting until all this flurry of activity breaks out some final processes. Opinions?

Jack Dernorsek
N44057

[barnstmr]

Re: Help researching AD 93-10-06

I am thinking of just waiting until all this flurry of activity breaks out some final processes. Opinions?

Jack Dernorsek
N44057

That would be wisest. After all... we have a little time before everyone is grounded. I plan to watch this unfold for a while... especially before I buy expensive struts. And meanwhile, I am learning what I can about NDT etc.. And I am hopeful we can teach the FAA a thing or two.

[VictorBravo]

Re: Help researching AD 93-10-06

The AD that was issued on an emergency basis for the Piper Cherokee was eventually rescinded or greatly reduced. I am guessing that there have been others like it. So there is merit to sitting back and waiting in terms of legality. But let's be fair and also give equal time to many many other AD's that have saved lives and are 100% necessary. You'll hear me bellowing as loudly as anyone else over short-sightedness in the FAA but it is far from a one-way street. We just all will probably have to get together and speak with one loud clear voice for an AMOC in this case.

[Ragwing nut]

Re: Help researching AD 93-10-06

Go back and read 99-10-06 on Pipers. It is word for word what the Taylorcraft strut AD is except they left out the Maule Tester which is an important part of the AD. Not because it relates to a Piper SB, but because it verifies a inaccurate eddy current reading as per the AD.

Mike