RV-10 Cowling/Firewall Hinge Alternative??

[bjdecker]

On both of my -7's and the -14, I used several pieces of .032" x 1.5" flange material installed around the perimeter of the firewall -- drilled out the AN426-AD3nn rivets that held the hinges in place and upsized to NAS1097-AD4nn.

Screw holes are spaced at ~2". The cowl halves are then secured to the flange with #8-32 x1/2" screws, with K1000-08 plate nuts on the flange.

The screw holes are counter-sunk, and the screws have small flange "tinnerman" washers under the head -- A/S part number 04-03895/39006F style (small flange, 100° #6). The #6 fits better on the #8 screws and gives a nice, clean look.

IMHO this is far simpler (and cheaper) than skybolt/camlocs.

[Blizzard]

Good Stuff. Thanks for the pix and the tip about the Tinnerman size. Should I use T6 aluminum for the flange or does it matter? T6-order. Doesn't matter-Lowes. LOL

[JonJay]

Like others, my lower hinges started to smoke rivets early on. I added a small piece of angle and nut plate on the inboard end of each hinge, just one screw and a large area washer for each hinge. Problem solved. Original hinges still there and doing fine, 900 hours.
It was an east retrofit on a flying airplane. My intent was to go back and replace the hinges with screws but never did.