CNs Update

[BruceMe]

I'm in the middle of doing my CN1 & 2.

General inspection issues; both CNs call for general inspection.

- On the rear spar forward tab of both wings did not have the required clearance of 7/16th from the center or 0.315 of edge metal was not met. Mine had 0.22", which was really visually obviously wrong.
- The tabs were the earlier shorter 2" high front tab, I resized them to the full width of the rear spar which is the newer method. It was not required.
- The CN1 was otherwise complied with on the right wing because the builder had installed wing walks on both sides.
- I found 5 rivet cracks in the top skin only on the rear spar (see separate thread). Per Vans, I am fixing that by replacing the inboard skin with the next wing rib 28". I have cut and sized the sheet, I'm waiting to finish CN2 to do the final drill-deburr-dimple-rivet.
- I found 10-ish smoking/failed rivets on both wings' bottom leading edge side of the wing near the root, I'll drill them out to 30 and replace them.

I'm about to begin work on the actual CN2 for the right wing from the top side (the sheet is already pulled way off). For those that might be reading this in the future, if you don't have a fuel tank, and you have wing walks the inner-most reinforcement is insanely difficult. It's not really obvious, but Vans did provide an out for this by letting you install that angle on the front side of the spar (if you don't have a fuel tank). I had to read the instructions four times, but that was a huge relief.

My general findings are that there are so many different configurations of wings and your actual configuration matters! The actual content of the CNs are trying to explain in words what's really better described in a flowchart. Take your time and read them carefully many many times.


I'm posting everything here, if anyone wants to look it over.

[Red Voodoo]

Bruce, Thanks for recording your experience for all to see. I've got a pair of partially-constructed "A" wings I'll be reworking shortly, and any information is helpful. Good work, and good luck!

[BruceMe]

I'm getting ready to put it all back together. Here's a shot.

[BruceMe]

So here's my dilemma... For any of you familiar, I have opened the wrong side, this CN is supposed to be done from the bottom, not the top.

I did this because I needed to open it up to replace the top skins anyway, so top side. Well, that's all well and good EXCEPT you can't buck the aft top skins because the angles for the mod interfere with the bucking bar

So I'm going to try really hard to zipper the mods and the front row as I go down the top wing... if I can contort my hands enough to do the final install of the mods after riveting the top skin above them... all is good, I'm done. But that probably won't realistically happen. If I can't do that, I'm going to open the bottom skin just enough to get my hands in to install the mods

-Bruce

[BruceMe]

I'm going to alter an old bucking bar with a slat to do these rivets

[BruceMe]

This is my answer to the question... how do you buck the rivets for the top skin when the mods are installed.

[BruceMe]

I just finished the right wing... just one more to go, and I won't make the same mistakes again. Should go much faster.

[BruceMe]

These CNs are the most intricate, cramped, complicated, and fiddly task I've ever done on an RV. If anyone is reading this in the future, find someone (me, even) and ask for pointers that shave off days of hemming and hawing and be less likely to make stupid mistakes. I'll try to make something for the bigs ones and maybe get it sticky'd by the admin.