26 - Mid Fuse Lower Structure (finished section); 27 - Firewall (tunnel sides; cover angles)

The fuselage is starting to take shape - this week saw the completion of the mid fuselage lower structure, which encompasses all the seat ribs and all the baggage ribs, as well as two bulkheads, much of which was back-riveted to the center bottom skin (thanks to my wife, who bucked the manufactured rivet heads using the back-rivet bucking bar).  Here are the tasks accomplished this week:

- Assembled aft gear brace assembly; riveted seat rib angles to aft gear brace assembly; back-riveted aft gear brace assembly to skin; clecoed center bottom skin to ribs and bulkheads
- dimpled baggage ribs; fluted lower aft flanges of baggage ribs; played with pneumatic metal sheet nibbler
- riveted step attach brackets to weldments to outboard baggage ribs; riveted step attach ribs to outboard baggage ribs; riveted side frame assemblies to baggage ribs; riveted everything to become a larger baggage rib assembly with side frames; riveted nutplates to floor stiffener and power outlet brackets; riveted nutplates to weldments
- back-riveted seat ribs to center bottom skin; riveted baggage ribs to seat ribs and bulkhead; clecoed center bottom skin to baggage ribs
- riveted baggage ribs to bottom center skin; riveted floor stiffener to side frames
- separated deburred firewall angles; deburred and riveted nutplates and cover angles to tunnel sides; riveted support angle to left firewall angle

The new update to Apple's MacOS screws up the order in which photos are uploaded to Blogger ... so these are once again out of order (and it's more of a PITA to reorder them than it's worth).

Riveted seat rib angles to seat ribs:

25 - Fwd Mid Fuse Bulkheads (completed); 26 - Mid Fuse Lower Structure (bottoms skins; seat ribs; baggage ribs)

This week saw the completion of section 25 and the start of what seems to be a very long section 26.  The fuselage is coming along and it was nice to bolt and rivet the seat ribs, and thus form the skeleton of the structure where my rear end will eventually find its home.  I dimpled the large center bottom skin - it was tough to get all the rivets but with a little bending, the center holes were not as much of an issue as I had anticipated.  The following were accomplished this week:

- riveted cover ribs and final-torqued bolts on forward center section bulkhead; reamed .311 and .375 holes
- deburred and riveted doublers to outboard baggage ribs and baggage ribs
- dimpled, fluted, deburred and attached nutplates to seat ribs; attached bushing clips, routing angles and doublers to ribs; riveted crotch strap assemblies (incl. nutplates); fluted outboard seat ribs and baggage ribs to match curvature of center bottom fuselage skin
- bolted and riveted seat ribs to F-01414 bulkhead; separated, deburred and primed seat belt attach lugs; deburred baggage ribs, routing angles, and seat belt lug brackets
- riveted seat lugs and lug brackets to baggage ribs; riveted F-01405 bulkhead to inboard seat ribs and outboard seat ribs and bulkhead angle; assembled and riveted Idler bracket assembly to F-01405 bulkhead; clecoed and match-drilled forward bottom skins
- match-drilled forward bottom skins; cut-out rectangles for gear legs; deburred and countersunk large skin stiffeners; dimpled and deburred small stiffeners; primed all stiffeners
- deburred forward and center bottom skins; up-drilled a bunch of holes; dimpled K1000-06 rivets
- dimpled center bottom skin; back-riveted nutplates, stiffeners and doublers to center bottom skin; separated, deburred and dimpled seat angles; straightened gear brace bars; primed gear brace bars

Reamed inboard 0.311" and 0.375" holes in the spar flanges: