2.7 Hours -

My least favorite part of the airplane build, so far, is the aft-most two feet of the fuselage.  It’s not that any of the construction techniques needed in this section are difficult, but the parts simply don’t fit together well.  Up to this point, everything in the kit has fit together perfectly.  However, it appears that I’m having the same issues as everyone else, so, build on!

Still not entirely happy with the fit of the F-711/F-712/F-779 assembly, I removed it from the aft fuselage, once more, and attempted to tweak the angle of the bulkhead flanges a bit more.  I’ve taken this off so many times now that reinstalling it has become a bit easier.  It still took me about 45 minutes from start to finish, and the fit still isn’t perfect, but it is much better than any of my previous attempts.  Therefore, I’m calling it good.

The next step is to drill the J-channels to the skins.  However, before doing that, I have to make sure the aft fuselage is straight.  This is really overkill for the match-drilled kits, but it’s easy to check, so I figured why not!

To check for straightness, I hung two plumb-bobs off the aft fuselage.   One was hung from the top of the F-706 bulkhead at the front of the aft fuselage, and the other was hung from the F-712 bulkhead at the rear.  The tooling holes in the top and bottom of the bulkheads are on-center.  If the string of the plumb-bob crosses both holes, on both bulkheads, the fuselage is free of twist.

The camera makes it look a little off, but the plumb-bob hung from the F-706 showed that the front of the aft fuselage is free of twist.

Another plumb-bob hung from the F-712 shows that the rear of the aft fuselage is free of twist.

Once I knew the aft fuselage was straight, I started drilling the J-channels to the side skins.  I did one channel at a time, starting at the front and working back toward the aft end.  The plans state to drill and cleco every fourth or fifth hole, making sure proper alignment of the J-channel alignment is kept, then go back and drill the rest of the holes…this is exactly what I did.  This wasn’t very complicated or difficult, but it took quite a bit of time.

Drilling the four J-channels to the side skins was easy, but time-consuming.

Everything was going fine with the J-channels until I got to F-711 bulkhead on the lower J-channels.  From this bulkhead aft, the holes between the F-779 skin and the side skins don’t line up perfectly.  I think this is due to the slight bending of the F-779 skin I had to do to get the bulkheads to fit correctly.  To fix it, I think the holes will align if I use a big clamp to squeeze the tail a bit.  If that doesn’t work, I’ll likely enlarge the holes to #30 and use bigger rivets.  However, I don’t want to mess with this area of the plane any more today.

The 6 or so aft-most holes are mis-aligned between the side skins and the F-779 skin. Fortunately, I have a couple of ideas for fixing this.

To wrap up the day, I drilled all of the bulkheads, except the F-711, to the side skins.  After I figure out the aft hole alignment issue, I’ll still have drill the holes in the bottom skin of the aft fuselage.