Confusion about wing spar nutplates

[jhearnsberger]

On p. 13-3 in manual. I did not match drill the holes shown on 13-5 that drill into the j-stiffeners. However, I have matched drilled and countersunk the holes below the ones that go into the j-stiffeners in this area.

I just finished step 2 on 13-3. I countersunk all of the nutplate rivet holes in the flanges except for the holes specified not to match drill that go into the j-stiffeners.

I thought I countersunk everything, but now on step 3 it is wanting me to countersink more.

Could someone please help me figure out what's going on?

Thanks,

Jake

 

[Wayne Gillispie]

In step 2 pg 13-3...you are mach csk just for rivets in places mentioned.

In step 3 you are mach csk the aft set of holes for the wing skins and ribs. These csk's will be deeper to accept the skin dimple so that you don't end up with gaps between flange and skin. Use the dimple test piece mentioned.

Check skin thicknesses and use appropriate test thickness. It will be either .025 for otbd nose skin and top outbd skin or .032" for the others.

 

[jhearnsberger]

So, in figure 3 p.13-3... The K1000-6 holes I have not touched. And I do not touch them for the entire section, is this correct?

Figure 1, I have countersunk all 56 places where the K1100-08 are located and the MS21053-L08's for AN426 rivet.

I still have not figured out the "skin and rib attach rivet holes" mentioned in Step 3??

 

[Wayne Gillispie]

Call me now 606-316-niner, zero, two, zero. I hate typing on my iphone!

 

[flion]

The last sentence of the second paragraph of step 2 directs you to the K1000-6 nutplates shown in figure 3. Countersink ALL nutplate rivets, and only deep enough to accept a rivet. Also get the rib attach holes in the tank area, since those rivets do not go through a skin - and are only deep enough for a rivet.

Then, in step 3, countersink all the remaining holes in the flange. The remaining holes will have a dimpled skin over them, so you must countersink a little deeper than before.

I am not sure why you have not match-drilled the J-stiffeners. I considered match drilling them to the skins but reconsidered and followed the directions. When you put the second skin on, you will find it difficult to match drill the stiffeners because it will be hard to reach in and keep them tight to the skin. Once the stiffeners are match drilled to the spar, then there is nothing to stop you from countersinking the row of holes on the flanges that it seems you are missing right now.