We need to find out where the hard points are for the wing retention screws. When I was taking care of the few wrinkles in the covering I found the hard point. This is easy to see when you heat up the covering in the area. The dowel hard points are installed on top of the wing at approximately 8 ½ inches from the wing root. The hard point is on the edge of the yellow strip and red leading of the wing. Below is a photo where I marked this location with a Sharpie marker. This will prove easy to find later with the Sharpie circle around it. The Sharpie will wipe off with Rubbing Alcohol so it’s the best marker for the task. Mark the hard point as I don’t drill the retention bolt holes until later on. I know the instructions say to drill it but… Its usually one of the last things I do. I don’t want to have screws around in the panel to rub on the other wing panel. This can cause some hangar rash…so I usually drill and tap the holes later on. This is important step so don’t forget it….but it can be done at the end.

Knowing the hard point is 8.5” into each panel and I know that 9-5/16” of tube is about ¼” too long. We can safely cut the wing tube shorter by about ½” to 5/8” to use the max length of tube and ensure the tube is passing through the false rib installed in the wing. This also gives plenty of meat for the wing retention screw in the aluminum tube.

I pushed a small thin section of music wire into each wing panel. About ½” in front of the wing tube location. I wanted to find the location of the false rib. In both panels this location was 7.5” from the root of the wing. Therefore we know the rib location is 7.5” and the hard point is 8.5’ in from the root of the wing panel. This isn’t a task that everyone needs to do but I wanted to make sure the tube was going through the rib. I also wanted to check the relationship of the hard point to the false rib. This was a little of CYA and since I didn’t build the wing panel I was not sure where the rib was located. This test told me what I needed and confirmed that Dave and Piedmont Models did their homework. So the information is for those of you that are concerned….The rib is there and out at 7.5 inches from the root.

I then proceeded to cut the wing tube shorter by 5/8”. This will give me just a little bit 1/8” shorter tube than needed to hit the wooden end caps. Once cut I used my belt sander to clean up the edge of the tube. If you don't have a bend sander A block with 100 grit paper will work well. You just want to clean up the burr on the end of the tube where it was cut. Use an x-acto knife on the inside edge of the tube to clean any burr that may be present. Be careful not to cut yourself on this burr. The idea is to sand it to eliminate sharp edges. These can damage the sockets in the fuse or wing panels, or cut your finger. I know I know...I'm not trying to mother any of you...just that is seems to reason somebody would cut their finger on the aluminum tube.

Important:

every wing probably has a slightly different depth for the end caps. If you have trouble getting the tube to go in about 9” into each panel you need to look inside with a flashlight and see if some glue is blocking it. I would say the absolute shortest you would want is 8.75” but you may be able to use the full tube. Without cutting it. It all depends on the end caps. Just double chekc the location of your hard points and the depth of the end caps. I feel if you are past the hard points then you are safely past the false ribs.

I cut the wing tube 5/8" and the result was a perfect fit. Next is the setup of the wing adjusters and the incidence of the wing. That will have to wait until tomorrow.