Question Avion Yokes

Hi Steven,
It's pretty clear to me. The approved PMA doc cites a 0.75 diameter shaft diameter for the PA 28-140.

I suggest you contact the owner of Avion and ask for a copy of an FAA field approval form 337 for the installation of one of his yokes to a 3/4 inch shaft.

With a previously approved 337 form, you can then apply to your Flight Standards District Office (FSDO) for a field approval for the installation of an Avion yoke on your airplane. 

Another option is to replace the bowtie yoke with a rams horn yoke.

There is information in the parts manual for that mod; I've contacted Piper Tech Support for more informaton.

I will get back to you with the Piper answer once I receive it.

FWIW there are many Piper Cherokee control yokes on eBay. 

Another avenue you might want to explore is to query salvage yards asking for a rams horn yoke on a 3/4 inch shaft. Start with Preferred Air Parts (www.preferredairparts.com), and Wentworth Aircraft. (www.wentworthaircraft.com)

Reputable salvage yards will allow a part to be returned for a refund within a few days after its received.

Let me know what you come up with.

Steve

I own a 1973 PA28-140. I’m having a Garmin GFC 500 A/P installed in February. I want to replace my bow tie yokes with Avion yokes. The problem is the way I read their STC the 1 1/8 shaft size doesn’t apply to the my aircraft. I talked with the owner and explained my issue and he said he’s sold thousands of those yokes for aircraft like mine.  You read the STC and tell me what you think. My shafts are 1 1/8.