I’ve been mulling over how to retain the hinge pin for the vertical hinges that hold the lower cowl to the firewall. I wanted something that is very secure, but easy to remove without tools. After some fiddling around, I stumbled on a solution that I really like. I mounted a K2000-06 nutplate part way down the hinge with a couple of AD rivets (I used AD instead of A for the extra strength). I then bent the hinge pin so that there is a depression where the spring normally sits. The spring doesn’t look like it’s stretched much, but this is a very stiff spring and requires a fairly good pull to get over the end of the hinge pin. I ran an AN507 screw into the nutplate backward and just tighten it down against the hinge (there isn’t a hole there because I didn’t want the screw to show on the outside of the cowl).
I’m super happy with this. It’s very light, easy to install and remove, but can’t possibly vibrate loose. And if the spring ever breaks, it will be easy to replace.
