1/15/2022 – 1.5 hours
The rear spar section of the plans is deceptively short and simple. There are only four sheets and fewer than 10 parts for each rear spar. There are, however, several things going on. First, there is a Service Bulletin from March 2016 regarding “Cracking of wing aft spar web at the inboard aileron hinge bracket attach rivets.” The SB parts kit is shipped with the wing kit, and it essentially replaces the original inboard aileron brackets. The plans have not been updated with the instructions for the SB, so you have to be aware of which aileron hinge bracket (inboard or outboard) you are working on and use the plans or SB instructions as appropriate. Another item I noted was drilling the rear wing attach bolt hole through the rear spar doubler plate and rear spar reinforcement fork. This is a critical hole that must be drilled and reamed with a drill press and appropriately sized bits – 11/32 drill bit and 3/8 reamer. I had to order the drill bit and reamer since they were not already part of my tool kit. The final thing that caught my attention was outboard doubler plate, which needs to be match-drilled (like the rest of the doubler plates) to the rear spar and then machined to put a hole for the aileron control pushrod through the doubler that matches the hole in the rear spar. The hole is not round, so this is more than simply using a step drill.