Seat Back Channel

The next step according to the instructions is to rivet the canopy deck rails (these sit on the top of the longeron in the cockpit area to create a finished edge) and then all of the pieces associated with the seat back support channel.  Take a look through the plans and you'll see why I stared and stared at things trying to figure out what order to do it all in.  The problem is, there are many different areas with rivets that wouldn't be accessible to buck if you put things together in the order Van's says to.  I went online to do some reading and found a lot of people who had followed the build order of the manual and came to regret it.  So instead of be able to jump right to putting all of these pieces in permanently, I'm going to have to just prep everything and then wait to rivet it together after the aft top skin (the one just above/behind the baggage area) goes on.  That skin has 3 longeron rivets underneath the seat back channel that can't be bucked at all if you follow the order Van's calls out.

While scratching my head about all of this, I made a discovery about a part I had made eons ago.  Each end of the seat back channel has a big piece of angle under it (F-705G).  A long time ago I made them and match drilled them to the holes in the channel.  I have no idea what I did wrong, but while the holes in the vertical side are fine, the 4 holes on the top side are way off on both pieces.  Thankfully I have some extra angle, so I made two more parts.  Drilling them in place vs as just part of a substructure at least guarantees the holes will be right this time.  It's just a few hours of extra work - something I've gotten used to being okay with!

I clamped the new angle pieces in place under the channel and match drilled the vertical portion to the vertical arm of the seat back support.  The 4 holes that I originally miss-drilled go in the big blank part of the angle in the picture below.  In the picture you can see the three skin rivets that are the problem.  Two of them LOOK accessible in the picture, but in reality they are buried next to the angle and a bucking bar can't get anywhere near them.  You can barely see the third rivet hole - it goes into the white tab right at the vertex of the angle.  Not a chance.  So that's why I can't rivet in the angle until after I've put the top skin on later.

After hours remaking the angle pieces and drilling them in place, next up was the canopy deck plate (F-757-T)

The plate sits on top of the channel and nests underneath the longeron.  The four clecos in the top are the holes that started this whole rebuild - my original holes were about an 1/8" off on both sides.

With the 757 plates in place, I then measured, drilled and countersunk holes in the longeron that will tie it all together (eventually, after those three pesky rivets are done for the top skin).

I've been waffling on whether or not to bite the bullet and do the Antisplat mod that allows the seats to recline a few inches further.  The big benefit isn't so much the extra recline, but the fact that it gives more shoulder offset between passenger and pilot (one seat in the normal position, the other a few inches back).  The problem is that the mod was designed for the sliding canopy.  It can be done for the tipup, but because of the latching mechanism it takes quite a bit of extra work to make it happen.  I had Rose come out and sit in the plane with me (should have gotten a picture - it was the first time of many that we'll be in here together!).  We're both small enough that even with the standard setup we have a couple of inches between our shoulders.  Given that, I just decided to stick with the existing design.  Yes, it'll be tight on the occasions that I take someone for a ride who is wider at the shoulders, but I still think it'll be fine.  The bang for the buck isn't worth it considering the number of times I'd want the extra shoulder room anyway.