Rear wing spars

With all of the main and nose ribs deburred and straightened, it was time to start construction of the rear wing spars.  The primary component of the rear spar is an aluminum Z channel, to which several doubler plates are attached in critical areas for reinforcement.  The inboard doublers (W-707D and W-707G) require trimming at a specific angle prior to being attached, and an opening in the middle doubler (W-707E) must be drilled to allow movement of the aileron pushrod.  For surprisingly simple structures, it seemed like it took quite a bit of time to get both of the rear spars ready for rivets.  It was rewarding to have them finished though.

Started match drilling doubler plates to spar channels

Trim lines marked on W-707D.  This will be used as a template for W-707G

Aileron pushrod opening started with unibit.  Remaining material removed with dremel.

Opening enlarged to final size and deburred.

Outboard portion of rear spar ready for rivets

Center doubler only requires 5 rivets at this time

Inboard doubler plates attached and ready for rivets

Rear spars finished