Vertical Stabilizer Attached

Posted On October 13, 2025

(Oct 5 & 12, 2025) The vertical stabilizer (VS) attaches to the rear fuselage with AN4 bolts per the KAI. However the bolt locations are very close to the edges of the skin, making it difficult to tighten the bolts (impossible with a normal socket, difficult at best with an open-ended wrench). Therefore, I replaced these AN4 bolts with equivalent NAS603 screws (-11P for the top two, -10P for the bottom six). I chose these screws since they meet or exceed the tensile strength of the AN4 bolts they are replacing, with the same CAD plated finish.

Attachment points for the VS, which includes the rudder hinge

Closeup view showing the AN4 bolts are too close to the skin edge to use a socket to tighten

Secured with NAS603 screws and torqued to 25 in-lbs

Here is the torque screwdriver I used: https://a.co/d/cyfMBla

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