I was about to drill the top and bottom skins on the right wing of my SB RV-7 when I noticed that the forward and aft faces of the spar caps are not parallel to each other at the wing root. In particular, the bottom spar cap seems to be rotated as shown by perhaps 1 degree (you will need to look carefully at the left side of the diagram):
I then checked the left wing, which has already had top skins and leading edge riveted on, and found that the situation is a bit similar. In that case it seems to be the top spar cap that is rotated. I suppose that when the close tolerance bolts go through to attach the wings to the centre section the caps will be forced to line up, but I wonder if the bolts will be very difficult to get in (or perhaps impossible?), or if it will be bad to have pre-loaded wing spars like that. Also I wondered if the angle of incidence of the wings might be affected by forcing the caps to rotate a bit. I can?t really see that anything I have done has caused this, especially on the right wing where I have not drilled anything yet (except the nutplates). I checked with another local RV-7 builder who is slightly ahead of me and he has also noticed something similar. Has anyone else seen this before or have any insight?
Thanks in advance!
I then checked the left wing, which has already had top skins and leading edge riveted on, and found that the situation is a bit similar. In that case it seems to be the top spar cap that is rotated. I suppose that when the close tolerance bolts go through to attach the wings to the centre section the caps will be forced to line up, but I wonder if the bolts will be very difficult to get in (or perhaps impossible?), or if it will be bad to have pre-loaded wing spars like that. Also I wondered if the angle of incidence of the wings might be affected by forcing the caps to rotate a bit. I can?t really see that anything I have done has caused this, especially on the right wing where I have not drilled anything yet (except the nutplates). I checked with another local RV-7 builder who is slightly ahead of me and he has also noticed something similar. Has anyone else seen this before or have any insight?
Thanks in advance!