Day 87

Got the composite wing tip riveted on today!

It was tedious work, but turned out so great. We began by placing a straight edge along the main spar so that we would be able to make sure our wing tip would be flat across the top.

On our first attempt it was very difficult getting the wing tip to line up properly. We used straps to pull it to tight into the leading edge, but as you tried to make it level with the straight edge, the bottom rear would come out to far. No matter how we tried to adjust it, it was just not sitting right. So we marked the holes with a black maker to see where the holes were lining up.

Once removed, we took a few measurements and found that how the composite was originally cast was not allowing it to fit in the hole properly. We marked out what needed to be trimmed and used a grinding wheel to trim it up. Then cleaned up the edges with some sandpaper and set it back on the wing.

This time it fell right into place. We then set about drilling into the composite material using the wing skins as guides. We would drill a hole, and then place a cleco so that it wouldn’t move and remain tight and lined up to the skins. Once all the holes were drilled we removed the wing tip and were able to take note of how much better the tip was fitting this time compared to the marks we had previously made.

Next we took the rib 14 and Cleco’ed it onto the rear section and match drilled the rear holes. Then sanded and scuffed the whole wing tip. After that we countersunk the appropriate holes. Lastly we used glue and cleco’s to hold backup washers on the inside of the composite end to give more rigidity when the rivets pull.

We then set the wing tip back up on the wing, ran the NAV light wires, Cleco’ed all the holes and set about removing one cleco at a time pulling each rivet. We did this so that there would be zero chance of the tip moving out of alignment.

Once we were finished, it turned out very well. The wing tip was tight all the way around the wing skin and looks really good. Very happy with how it turned out, for relatively little instruction to go off of.