Skeletons

Today I primed an riveted the rudder stiffeners to the left and right rudder skins.

Stiffeners Being Riveted to the Rudder Skins

I finished riveting all the stiffeners to the left skin and when I was picking up the skin to switch it with the right skin, I realized I had reversed the smallest stiffener! AARRGGHH! Dang it! I had to drill out 11 rivets from R-915H. Ok, I'm pretty good at drilling rivets out now. So, I drilled them out, turned the piece around and riveted again! It runed out well. All rivets went in very well with none needing repair. Cool! I love to back rivet. If only it were possible to do it this way on the whole plane. But alas, it is not. Moving on.

What's Wrong With This Picture?

Next is building the rudder skeleton. Start by clecoing the R-902 rudder spar and R-904 bottom rib together then enlarging the ⅛" hole in the bottom rib to ⅜". I used my step drill bit for this and made quick work of that task. Next I fabricated the R-917 shim per the plan drawing. Note here: just cut the shim to size and do not drill the holes yet. You don't have enough dimensional information anyway.

R-917 Shim Cut to 1⅛" x 3½" Per the Drawing

Next I bolted (using a ⅜" hinge bolt) the R-405D rudder horn on the rudder spar and match drilled the four holes through the upper edge of the rudder horn to #30.

Horn Bolted to Spar Ready for Match Drilling

Next I cleco'd the rudder horn to the bottom rib to check the fit. The radius of the top of the horn needs to be trimmed down a bit to fit with the rib flange. A few passes on the ScotchBrite wheel took care of that. Fits like a glove.

Taking a Little Off the Top!

Trim Just Enough to Allow a Tight Fit

I then cleco'd the bottom rib and the rudder horn to the rudder spar. Now is when you slide that R-917 shim into place. It goes between the rudder spar and the horn then once in place, you match drill it to #30 and cleco as you go. Now, cleco the reinforcement plates, R-606PP, R-607PP and R-608PP to the rudder spar. Note that the 606 plate attaches to the forward side of the spar while the 607 and 608 plates attach to the aft side.

R-606PP On the Forward Side of the Spar

R-607PP On the Aft Side of the Rudder Spar

R-608PP On the Aft Side of the Rudder Plate

Now comes fluting of the rudder tip rib and the counterbalance rib. They have you get this just right. All flanges need to be straight, both along the hole lines as well as being square to the rib web. Do this with your hand seemer if necessary. After that's done, cleco the counterbalance rib and the tip rib to the rudder spar. Match drill those holes to #30. Next, cleco the counterbalance skin to this whole assembly. It's a little tough here. The holes seem not to line up as well as I'd like. I will remove then check the straightness of the ribs again.

Tip & CB Ribs Cleco'd to the Rudder Spar
Without the CB Skin Attached

I'll hold off match drilling #40 holes to make sure I have all ribs straight and in better alignment. Stopping here for the evening. Take Care and Thanks For Reading!

HOBBS Meter - 71.7 hrs