The plans have me thoroughly confused about dimpling/countersinking the wing skins for the fairing attachment screws. I'm currently verifying the steps already completed in my QB wings. There are many steps that were missed.
On page 41-05, it seems to be indicated that all of the wing-side attach screws are AN507C-832R8 flush screws, including those on the fuel tank attach brackets. Yet, on page 16-02, it's stated very specifically that, on the top inboard wing skin, only the aft-most screw hole is dimpled. I would presume that the others would be countersunk but there is no mention of that. The nutplates are riveted in place on the next page thus making it difficult, even impossible, to countersink them later.
I have the same issue/question regarding all of the other attach holes on the bottom wing skins and fuel tank skins. I can dimple the holes in the fuel tank skins except that I have to get some Proseal out of the way. I can also countersink the holes on the bottom wing skins without any problem.
The fuel tank attach brackets are another matter. On page 18-04, the two forward #19 holes on the shim on the top of the attach brackets are dimpled yet the other five holes on the top and bottom of the brackets are not. The proximity of the attach bracket makes it impossible for me to dimple the hole for the one-leg nutplate. I did talk to the factory about that one and we decided that I should just drill out the hole to clear the dimple in the fairing.
All of the five nutplates on the top and bottom of each attach bracket were installed. Therefore, if I'm going to countersink these holes, I've got to drill out the rivets in all of these nutplates, except maybe the one-leg where, if I'm careful, I could still drill out the screw hole.
Interestingly, also on page 16-02, it is specifically states NOT to dimple the rib top flanges under the wing walk doublers. However, I would expect them to be and indeed they were on my QB wings.
I can see what I need to do in all of these cases to accommodate the flush screws. However, because of the way the plans are specific about the holes to be dimpled (page 16-02 and 18-04) makes me wonder if I'm missing something.
Can anyone help me clear up these mysteries?
On page 41-05, it seems to be indicated that all of the wing-side attach screws are AN507C-832R8 flush screws, including those on the fuel tank attach brackets. Yet, on page 16-02, it's stated very specifically that, on the top inboard wing skin, only the aft-most screw hole is dimpled. I would presume that the others would be countersunk but there is no mention of that. The nutplates are riveted in place on the next page thus making it difficult, even impossible, to countersink them later.
I have the same issue/question regarding all of the other attach holes on the bottom wing skins and fuel tank skins. I can dimple the holes in the fuel tank skins except that I have to get some Proseal out of the way. I can also countersink the holes on the bottom wing skins without any problem.
The fuel tank attach brackets are another matter. On page 18-04, the two forward #19 holes on the shim on the top of the attach brackets are dimpled yet the other five holes on the top and bottom of the brackets are not. The proximity of the attach bracket makes it impossible for me to dimple the hole for the one-leg nutplate. I did talk to the factory about that one and we decided that I should just drill out the hole to clear the dimple in the fairing.
All of the five nutplates on the top and bottom of each attach bracket were installed. Therefore, if I'm going to countersink these holes, I've got to drill out the rivets in all of these nutplates, except maybe the one-leg where, if I'm careful, I could still drill out the screw hole.
Interestingly, also on page 16-02, it is specifically states NOT to dimple the rib top flanges under the wing walk doublers. However, I would expect them to be and indeed they were on my QB wings.
I can see what I need to do in all of these cases to accommodate the flush screws. However, because of the way the plans are specific about the holes to be dimpled (page 16-02 and 18-04) makes me wonder if I'm missing something.
Can anyone help me clear up these mysteries?