Longeron Drilling #1

Time: 4 Hours

I got 4 hours in the Hangar before giving to grabbing the Harley and hitting the road to see the fall colors on this 80° Sunday. First up was to do some final tweaking of the 2 aux longerons. I wasn’t happy with the way they were lining up with the aft gussets and needed a little twisting for them to line up just right. After that it was time to line up the lower longerons and clamp them into their final position for match drilling. You want to make sure the longeron is tight against with engine mount as well as the gear tower weldements. I used various type clamps to hold the longeron in place after lining it up.

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IMG_4293.JPGYou start with the aft most hole of the bottom skin and drill up using the skin as a guide into the longeron. You then move to the forward most 4 holes that go through the skin, the longeron and the engine mount. Opening those holes up with a #12 drill to allow for AN3 bolts. I inserted the forward and aft bolt in those 4 holes to maintain the longeron position.

IMG_4298.JPGNow that I had the forward end and aft end locked down I just worked my way down the longeron drilling each hole and cleckoing them as I went.

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IMG_4295.JPGThere are 2 holes drilled up through the gear tower weldement that got opened up to a #19 hole. These will have screws in them and will need a flush head on the underside of the skin. This will allow the landing gear to sit flush on the underside. So after drilling those holes I grabbed the #19 countersink bit and cage to drill those holes.

IMG_4297.JPGThat’s where I stopped and went for the Harley ride. Not a whole lot today but any work in the Hangar is good!

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