6A Gear mount hole issue

Went to install my quickbuild kit 6A landing gear mounts and noticed one of the predrilled holes is so close to the radius, it will be impossible to get a bolt head or nut in there. I'm considering spotfacing the weld or making a steel shim to match the radius and using a MS21042 nut instead of the AN 365 nut. Even with the small nut, it may be too close to install.

I'm worried that spot facing the weld might cause a weak spot, but a shim would have to be very thick and may also cause a week spot.

What would you do?



Thanks, Scott from Olympia,WA

I believe this was a frequent pain in the arse

Sdemeyer said:

........ I'm considering spotfacing the weld or making a steel shim to match the radius and using a MS21042 nut......
What would you do?

Click to expand...

First, read this from FAA regarding MS 21042 nuts.
http://rgl.faa.gov/Regulatory_and_G...8925ec2f1c86257cc800611b60/$FILE/HQ-14-16.pdf

I had the same issue and I reverse spot faced that area after I used a small Dremel grinding ball to rough out the area. I also had to drill/grind a small mouse hole into the adjoining stiffener to allow both the spot face tool to operate and to allow the Nylock nut to fit. Many others have done the same.
Here is a poor picture of that spot on mine. Disregard the washer stack next to it. It was a work in progress. The other mount had one so close that the stiffener prevented the nut from turning and I had to file a small flat spot on the washer. It was torqued from the bolt head side. Do what you have to....

WenEng said:

First, read this from FAA regarding MS 21042 nuts.
http://rgl.faa.gov/Regulatory_and_G...8925ec2f1c86257cc800611b60/$FILE/HQ-14-16.pdf

Click to expand...

This issue with the MS 21042 nut looks to be a manufacturing/testing issue. With my left main gear using this nut, looks like I will make habit of inspecting that on the next inspection time.

disregard.