hello scott,wondering if you have come up with a ptt switch install on your control yoke yet, like to do the same as well. mark

I recently picked up a ’69 Yankee that was at the late Ken Blackman’s shop going through restoration. This plane has a later style Grumman left yoke that has been drilled for a PPT switch. This looks like it was recently done, but I did not find a log book entry or a record in Ken’s shop notes about it being done. So I cannot say for sure this was done by Ken’s shop or by someone else. The right yoke was missing.
If the picture I attempted to post with this comes through, you can see it was drilled straight down through the handle and out the side near the bottom. It was then drilled on the horizontal arm toward the yoke center and then another hole into the center. The tube was also drilled behind the instrument panel to route the wires out. This allowed the wires to be routed from the switch location on the left thumb rest to the inside of the yoke tube and back behind the instrument panel with no exposed wires. The hole on the bottom of the yoke handle could be filled with a putty and painted then I guess.
My concern with this and has been discussed in the past is would this drilling weaken the yoke handle? I plan to doing some testing to make myself comfortable that in the future I don’t make for a real exciting day by having the yoke handle break off just as I enter a landing flair.
On my late AA-1B with the same yokes some 20+ years ago I installed the Warren Gregoire slip on yoke grips with PPT switches built in. They have served me well and I still like how they feel. You do have to route the coiled cord. I might do the same with the Yankee.
I also brought home from Roscoe’s shop when I picked up the Yankee two new old stock yokes that are bare mettle that need to have the finish done. At the time I was not sure I would use the drilled left yoke that was installed, and the right one was missing.
I understand they used a rubber coating like that is done on tool handles. That is what I was going to look at using unless someone has a better idea.