[Stiglr]

That shouldn't be too hard.

If you have a wing root cross section (you'll find it on many good sets of 3-views) you can create that as an extruded poly line and "make hole" in the fuselage with it.

Then, make sure the wing object you create has the same number of vertices in the same relative locations as your hole, and then use "snap vertices together. Perhaps a better solution might be to only do this for a short section of the wing, so that the wing can be "broken away" (if you're doing flight sim work), and so that the majority of the wing itself is its own object, not all one big fuselage...