Today I finished up the heat duct vavle cables. The cables were adjusted and range of motion was verified. The spherical bushing retainers were secured and the cable sheath was supported where necessary using Adel clamps and standard techniques.
The 2" SCAT tube was reinstalled on the bypass valve and secured with hose clamps.
Next, the CF panel and subpanel were removed. I decided to reinforce the upper fuselage subpanel further due to spring load that it will need to support for the rudder trim. After many different ideas, I settled on the following.
Remove lower two rivets on each subpanel overlap. This overlap joint was conveniently located directly below the upper fuselage outboard ribs.
Fabricate a lower mount to support an 063 x 3/4 x 3/4 stiffener. The lower mount was fabricated from the same 2024 angle and is 1 3/8" long. A #12 hole was drilled in the center of one side, 5/16" from the edge. All holes and edges were deburred and smoothed.
The stiffener was fabricated from 063 x 3/4 x 3/4 angle and is 10 1/2" long. A #12 hole was drilled at each end for an AN3 bolt. The stiffener was drilled such that the vertical leg lays against the fuselage rib.
The stiffener was bolted to the lower mount and clamped in place. The lower mount was then match drilled to the subpanel and the fuselage rib was match drilled to the stiffener..
All parts were removed and deburred.
The lower mount was then riveted to the sub panel with AN470-4-5 rivets.
The stiffener was then bolted to the lower mount and the fuselage rib.
Although probably not necessary, this arrangement was completed on both sides of the subpanel. In retrospect, supporting only the left side, where the trim actuator will be mounted, would have been sufficient. The panel is now exceptionally rigid.
Of all the ideas that were considered, this was probably the easiest and it certainly stiffened the subpanel.
