Tried and True
A little update as we are getting ready for Oshkosh 2019. Wow, time flies! Faster than most airplanes anyway. After SNF19, we had as our goal of building and testing our wing structure. This is what we have been doing for a while now. I always think things will go faster than they do. After a lot of effort, we did it! We had to build a wing and a test fixture as well. Our engineers crunched the numbers and developed a test regime. Our team successfully tested the wing panel to it’s design limit load of 4.4 g’s with no permanent deformation. We then tested her to design ultimate load of 6.6 g’s plus as much extra weight as we could scrounge. +300?? Measurements all along the way, but after the last loading there was about an 1/8” of permanent deflection in the spar and some slight wrinkles in the upper surface of the skin at the spar flange rivet line. Compression loads were crazy high during the test and you could see diagonal waves in the upper skin. Those were about a quarter inch to their crests. This was expected and within margins. Really cool tho! The test started after work around 5pm and went into the evening till about 8pm. Many hands makes for light work and we had a great crew. Lots of 40 pound gravel bags to put on and take off the wing multiple times. After the test was over we celebrated with champagne and beer (ok, some of the beer and pizza happened during the test). The wing panel weighed 31 pounds and held over 2800 pounds. Paul mentioned after the test - “we can lighten it!” I said, “lets up the g loading!”. As of now, we are working very hard to get to Oshkosh with as complete an airframe as possible. We removed the landing gear and the unfinished center section wing panel. Scott machined some of the internal landing gear components we needed to finish and I welded up the scissor link mounting lugs and misc. gear parts. After fit-up, they are ready to paint - this weekend. The center section unfinished wing has just been skinned and we are getting ready to re-install it. We will need to cut-out and drill the two major plates that join the two wings together at the centerline of the aircraft. Then ream the mounting holes to their final size on the aircraft. Our goal is to build at least one additional outboard wing panel for Oshkosh and have her back on gear and engine installed. Then as much detail as we can add in time. Since SNF, we also covered the rudder and elevators with silver Oratex fabric. I still have to rib stitch and tape the edges. I want to paint the rudder in red, white and blue stripes if we have time. We are pushing for it! Talk soon! Will add some pics from the test over the next couple days. Happy 4th! God Bless America!