Whatever i try I get one or more edges that are not tangent. Here, a networksrf. MatchSrf does not want to do all four edges for me at once and doing them one at a time just shifts the location of the non-tangent edge.

Hm. I don’t think you can have 4 tangent edges on that surface due to the sharp kink upwards in the leftmost corner (in picture).

This is what I could achieve with XNurbs interpolation. Also there are two other edges in your surfaces which are not very good as can be seen with the zebra analysis.

The initial surfaces just won’t allow tangent matching these edges directly. Needs more preparatory work.

I guess this problem could be expanded to how to fill the entire area, including the triangular area. I keep going back to this problem and have not found a good solution to this area.

An observation: The initial surfaces are not very dense. With each surface I add and match, the density of the new surfaces grows. This, as the last hole to file is the most dense.

Another density problem is sweep2 generates really bad shapes for this purpose in most of the sections (I have previously posted examples of how Sweep generates really horrible shapes here). I have to resort to the dreaded NetworkSrf for more surfaces than I would like. There are sweeps where possible.

I note that the blueprints do not have measurements for this area. There are measurements forward and aft but non for this. It must have been problematic for the original drafters as well.