The second step was to place the forward spar over the aft spar so that it is level, parallel to the aft spar and positioned so the chord line is straight. I used a laser level, a digital level and plumb bobs to set the spars in place. Using a string along the leading edge of the forward spar I checked to any sagging in the spar.
Then I clamped the ribs to provide some additional strength. The next step is to drill the rivet locations for the ribs.