We are replacing the aileron control cables with new ones from McFarlane Aviation. McFarlane does not have a PMA cable in this case so I had to send my existing ones to them in order for them to fabricate new ones to original spec. I am working with the local FSDO on a field approval but the DAR from McFarlane surprised me yesterday by saying that technically they can probably be installed under AC 43-13 as an owner produced part (commissioned in this case since it was McFarlane not me who "produced" them).

For others who have replaced cables - did you get a field approval or just a logbook entry citing 43-13 ?

Thanks,

- Charles

Hi Charles,

Unfortunately I can be of no assistance to your question however I am very interested in the condition of the old cables, particularly where they were going around any "corners."

Thanks,

Ed

P.S. I'm very grateful for all your efforts on this forum!

I agree with the idea of owner produced part. Based on what Kristin recently posted:
2. The owner provided the manufacturer with materials from which to manufacture the part.
3. The owner provided the manufacturer with fabrication processes or assembly methods to be used in the manufacture of the part.
4. The owner provided the manufacturer with quality control procedures to be used in the manufacture of the part.
5. The owner supervised the manufacturer of the part.

I think there's an argument that you satisfied items 2, 4, and 5 in your conversations and dialog with McFarlane as well as providing them the old cables from which they could determine sizes, diameters, lengths, etc which is all part of quality control in ensuring the part was made correctly.

I have read FAA guidance that specifically says that sending a part to be duplicated meets all the requirements of FAR 21.9(A)(5), which is the provision allowing the owner/operator to fabricate a part. The invoice from McFarlane may specify that they duplicated the part per the owner's request, in which case the mechanic can add that to the log with his/her entry for installation. If not, you as the owner can make an logbook entry to that affect and I recommend saving the invoice anyway.

Thanks everyone who contributed to this thread in answering my post. Before I received the replies I also talked to Zach Grant on the phone and he pointed me to the Jul/Aug 2002 copy of FAA Aviation News published on the FAA website here -> https://www.faa.gov/news/safety_briefin ... ug2002.pdf which has a very good article on subject. I'm also attaching a PDF copy to this post to help others that follow looking for the same.

Additionally Matt Kurke had a good FAA response letter on the subject of Owner Produced Parts published on his website and I've attached that here also.

Finally the local FSDO agreed that a simple logbook entry and leveraging "owner produced" parts was the way to go (I'm also pretty sure they just did not want to deal with a Field Approval of any kind). They referred me to AC 23-27 on vintage aircraft (any aircraft produced prior to 1980 essentially), and also AC 43-13 does have sections dealing with cabling that contains the same milspec numbers as provided with the McFarlane cables.

Both of the above reference documents do specifically state that I participated in the design by providing my old cables to McFarlane as a template to reverse engineer. As Kristin pointed out 14 CFR 21.9(a)(5) deals with this topic.

Thanks for the help on this.

- Charles

FAA Article.pdf

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Owner_Produced_Parts.pdf

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Thanks Charles!