Tailcone – Part 4

Starting off on page 10-10 and installing the Aft deck on the tailcone.  Initially I was having some issues trying to get the skins to line up correctly with the aft deck, and realized this was a self-inflicted issue.  I initially cut F-1010B a bit long due to my previous issues with the J-stiffeners being too short.  Even so it appeared that with the F-1010B being long it wasn’t an issue (see photo below)

As I tried to clamp down the aft-deck as instructed, things were not “pulling together as they needed to.  Eventually I started to “build on” and figured if I kept the longerons properly positioned against the skins I could still keep going before I had to drill aft deck to the longerons.  The additional photos show where I had a gap between the edge of the aft deck and the skin which will be a problem when I go to drill.  Next I begin to drill the skins to the longerons.   NOTE:  the plans call for you to drill with a 3/32 drill, not a #40 drill.  My brain converted 3/32 drill to #40 and I just went with it.  A post on the VAF forums caught my attention to my mistake.  Not a huge deal as you eventually final drill to #40, but under drilling first, then doing a final drill with reamer will get you better results.  All goes well and I only made a slight error in drilling into one of the tabs for the ribs.  Then it’s on to match drilling the remaining holes on the skins (except for the holes common to F-1006).

The plans notes regarding F-1006 have confused me a few times, so I’ll just say that I DID drill the holes common to the J-Stiffeners and the longerons into the F-1006 bulkhead. (I also dimpled those holes as appropriate later on).  Basically if it is just skin and the bulkhead, I left it alone.  I may be wrong, but the plans are just murky enough that I don’t want to go to attach the tail to the fuselage only to find that I “should have done this early”

Anyway, another comment is working with this many clecos kinda sucks.  I had thought about a cleco pneumatic installation tool and decided to go ahead and order one.  Probably won’t really use it on the Empennage at this point, but I’m sure I’ll use it on the wings and fuselage.

Once all the side skins are matched drilled, I start attaching the top skins to the tail.  Once the first skin is on I’m looking at the plans and realize that F-1010B may be causing a clearance issue after all.  Cut it down to size, and funny how things start fitting together the way they should.  Once that is done, I drill the holes into the J-stiffeners as described in the instructions.  Next I begin to attach the forward top skin.  (I didn’t get it on camera, but I did Flute the ribs as described in the instructions.) It’s amazing how as you put the clecos in the sheets form up so the punched holes line up.  I match drill (not on the video) the top forward skins and then match drill all the holes (except F-1006 where there are no stiffeners).

Then I fabricate the Horizontal Stabilizer attachment bars, get them set up and begin to final drill the aft deck into the longerons.  I do end up staggering my drilling around the aft deck to avoid any of the dreaded “twist”.  In a few areas I need to use the 12″ long drill bits, but overall nothing crazy.  At this point admire your porcupine tailcone as the next steps are to take the whole thing apart!



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