We have been back in the shop working on the prototype number 2 aircraft getting it ready for the EAA air venture show in Oshkosh Wisconsin. We wanted to be able to show the dope and fabric version of the aircraft at the show as well as the ultralight version. In this picture here are starting to finish up the wing tip are
Although the primary structure is very close to the same as the ultralight version there are many modifications that are done to reduce the total amount of drag on the airframe. In this picture here we see the trailing edge at the wing tip and the transition to to the very end of the wing tip.
The inboard rib has to create a box structure so that all of the dope and fabric will have a location to attached to while the wings are in the folded position.
All of the ribs on the aircraft are manufactured from .5 ×.035 wall thickness 6061 T6 aluminum tube. the inboard box structure will be riveted to the top and bottom ribs. Each one of the ribs will also have 1/8 inch holes spaced approximately every 4 inches to be used for fabric attachment to the structure.
The top and bottom sections of the inboard wing box structure are curved by using a crimping tool to shrink the flange and strategic locations forming the exact shape of the airfoil.
The wingtip trailing edge rib installed in place using a 1/8 inch aluminum pop rivets.
The new completed wingtip.
So this completes the new dope and fabric wing assembly with the exception of the covering. We will leave the covering off so that we can show the entire structure of the airplane uncovered for the airshow. in this picture we see a little bit lower profile airfoil but on the ultralight version of the aircraft. We are using a NACA 23015 airfoil which should be pretty close to a NACA 23012 in between the ribs where the fabric sags.