Ok

Here is the next problem I face. Lets assume I want to model the fuselage as one piece sweep or network and then boolean out the cockpit opening.

Michael suggested to me this is the best way to work with nurbs rather than the approach in my first post.

Lets assume I decide to create a boolean from the side view to cut out the cockpit opening. How do I know or how can I work out what shape my cross section curves need to be in the cockpit area (yellow curve) so that when the boolean is done the cockpit shape matches the plan view ?