Modelling a fin and rudder for a plane

Of all the things in S3D, the ones I find most confusing are lofting and subtracting. I just don’t get the logic. I currently have a profile of a fin and rudder for my full-size plane. I also have the airfoil shape (I’m using half the shape, so I can join them later and get a perfect centre line). What I’m trying to do is to somehow intersect the two shapes leaving the fin/rudder with the airfoil shape.
Fin and rudder.step (170.3 KB)
Fin and rudder 2.step (170.4 KB)

Hi mate,

Sorry I’m unfamiliar with aircraft lingo. Is this what you’re trying to achieve? If it is then I’d be happy to explain it further for you.

May be help too:

Or:
https://www.instagram.com/tv/CkSiZhDtgP9/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==

Hi. Nope - I did that and one ends up the the inverse of what is required. Basically I need to end up with the two pieces (fin/rudder( not simply square lofted, but with their plans cut out of the smooth airfoil shape.