Longeron Drilling Finished

Time: 8 Hours

We got back on our weekend breakfast schedule after the thanksgiving holiday this morning. After reviving my build spirit with my friends I got right back to the Hangar to start the work. Today tasks were to finish up the longeron drilling. I counted 404 holes in the upper longeron alone. I had finished the drilling up to the aft fuselage skins the other day and that’s where I started today. Not a whole lot to say about this other than I spring clamped the skin to the longeron and used my drill cup to keep the drill bit square. I just worked slowly aft as I drilled and clecko’d.



IMG_4911.JPGHere is another cool view of the worked I just finished.


IMG_4912.JPGI then grabbed the #40 reamer and hit all the holes on the aft bottom fuselage skin on the tail come. There are a couple of holes that need to be match drilled here as well. Here is a couple of shots actually showing me building and don’t laugh at the Croc’s I’m wearing they are the perfect Hangar shoe. 🙂


IMG_4899.JPGAfter the final drilling was done on the bottom skin I grabbed the top of the 4 bulkheads and put them in place.

IMG_4915.JPGWith those in place I grabbed the top skin and clecko’d it in place.



IMG_4918.JPGThe top skin really stiffens things up and aligns everything perfectly. The aft deck is next, this is the area where the horizontal stab will sit and get attached. I squared everything up and clamped it in place for match drilling.


IMG_4919.JPGBefore I drilled I marked the notches on the longerons where the HS attach bars will extend up through.

IMG_4921.JPGI also marked out where I will remove some of the top flange of the longerons at the aft end.

IMG_4922.JPGThere are 2 angles that get attached to the aft deck and the farthest aft one has 2 AN-3 bolts that go thru it so I drilled those to a #19 and final sized them to a 3/16″ with my reamer.

IMG_4934.JPGFrom there I moved up to the cockpit rails. These need to sit flush with the mid fuselage side skins to form a nice joint as they will be seen every time you enter the plane. So I squared the edges up and used some clamps with small blocks of wood to hold them in place as I match drilled thru the longerons.


IMG_4924.JPGI worked my way forward lining up the edges as I went forward.


IMG_4926.JPGI had to use several clamps to hold the area where the forward side skins overlap the mid side skins to get a clean as possible edge there. I will scarf these skins to help them lay nice.

IMG_4927.JPGAfter I finished both of the rails, which turned out perfect, I moved on to the gear tower tops. These have a flange at the top that needed to be match drilled to the longerons. They don’t sit tight and need to be clamped so that their outboard edge lines up with the corner of the longeron. The plans suggest ratchet straps so that what I did.


IMG_4928.JPGWith the straps as tight as I could go I used another smaller clamp to help squeeze them together and they lined up great. I then match drilled them and clecko’d them up.


IMG_4932.JPGLast thing I did for the day was to clecko the set back roll bar attach brackets to the side walls.

IMG_4930.JPGAnother great day in the Hangar and got a ton done. I love days like these. The down side was I ran out of 1/8″ clecko’s and will have to remove a few in other places so I can continue. This is a good problem to have! 🙂

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