Landing gear fairing pin - floor wear

[Bryan Cotton]

My landing gear fairings have two pins, that insert from the middle. One goes down into the wheelpant, and the other goes up through the floor. The problem is the 0.032" floor did not stand up well to the steel hinge pin.

I took a step drill to it until it was just a hole - maybe close to 3/8" before it was cleaned up. Then I used my holesaw collection to make a 0.063" 7075-T6 aluminum washer and a 0.025" stainless washer. I laid out 4 pilot holes for rivets around the perimeter. I drilled it to the floor, sort of centered on the hole I just cleaned up. Then I marked the pin entry point on the stainless, and drilled a hole there. Started with #40 and worked up to a #21. I also angled the drill after to simulate the angle the pin would go through the floor at. Then I clecoed on the aluminum washer inside, and continued the hole for the pin.

I put the thin stainless on the outside, as well as the rivet heads, so there would not be interference with the landing gear fairing.

This is something to consider if you are in the build process. The 0.032 6061-T6 floor is no match for the hinge pin and all the movement associated with landings.

[GraemeSmith]

I had one of those till I shortened the pin. I drilled the hole parallel - deburred it and popped in a rivet on sealant to keep the exhaust out.

[flyguy0609]

Bryan, I work as a Quality Manager at a machine tool shop. Among other things, we produce pressings for a number of industries including aviation. One of our products is a stainless steel shim for use on 747's and 767's. The production plan calls for Passivation of the part. Passivation is a chemical treatment that renders the surface of a treated SS part chemically inert. this link explains it nicely; https://www.besttechnologyinc.com/passi ... ssivation/

While SS is corrosion resistant, it can still rust and can participate in galvanic corrosion. Sending a part out for passivation may not be a viable option everywhere, however an acid etch using citric acid followed by a coat of primer will give the same results.

Always ask and pay up for the material certs. The certs will indicate if the part has undergone any treatments.

[Bryan Cotton]

Thanks flyguy! The piece of stainless came out of my scrap bin. I'm assuming the constant oiling of the area will also help hold corrosion at bay.