Q about note on piper drawings CD "magnetic inspection required"

[violinmaker]

I have seen that as a numbered or lettered note in some of the drawings----- but then when I search the page for what part on the drawing that note is referenced to------ I havnt seen it------- so what parts need "magnetic inspection" ? Did they print the note on pages that do not reference that note ?

Tim

[SMO22]

Are you able to take a screen shot of the drawing and post it, or upload to imgur upload and link it

[violinmaker]

I will take a pic with my digital camera----
I have seen this not on more that one page I think-----

[Vagabondblues]

I have seen that "note" on many welded components, landing gear, fin, rudder. Some of those drawings simply show on the parts block with a statement "added in 1952".

I think they want the whole completed structure inspected for surface defects at the weld areas using a magnetic yoke. https://ndtsupply.com/magnetic-particle/yokes.html

[violinmaker]

I kind of figured it was a mag particle test-- but I never see that note with an arrow pointing to any pieces out on the drawing its self---- How did you conclude it applies to EVERYTHING on the page ? Seems like it would SAY that if that's what they wanted...… instead of a "note"..... The other "notes" have that note's letter and an arrow pointing to what it applies to …….


Maybe I need to self educate on using mag-particle NDT techniques----

[Vagabondblues]

It is common in aviation to perform MPI on parts that are exposed to torsional loading. Crankshafts and camshafts are good examples. You can change how the magnetic field flows through the part to see longitudinal and traverse cracks. To see the cracks you need about 1000 amps for a crank and 500 for the cam. Having performed Magnaflux testing I could not see how it would be practical to perform on a small welded assembly or a completed airframe. What would the high amperage settings do to a .035" tube? The lowest setting on the machine that I use is 100 amps. Not to mention how would you get a large part like a rudder into the machine?

If you look at the rudder assembly for example. I assume....the note applies to the whole drawing as it is not mentioned in reference to any of the pieces or sub assemblies. However, you have a central tube to which you have welded multiple ribs at 90 degrees to the tube. All of the stresses from welding the ribs to the tube have built up torsional load in the tube. Also, some of the drawings require TIG welding in certain areas. Not to digress into a discussion of the benefits, problems or process differences, but I would use a MPI inspection to ensure that the build up stresses did not cause cracks on something like the tube that is a central part in the rudder.. The yoke is portable an can be easily used on something like a rudder or complete airframe.