Hi Jacob, right now the end of your wing has a planar end cap on it here:



Before you try to blend it you want to delete that end cap so that the edge you are blending only belongs to a single surface, the wing surface and is not also attached at the same time to the planar end cap surface.

If you blend an edge that is attached to 2 surfaces it's basically random which surface it will decide to be smooth to, and it can easily decide to be smooth that planar cap instead of to your wing.

Once you delete the cap and make the edge only belong to the wing and not attached to anything else it will then avoid that possibility.

So that's one thing anyway, but also in order to get a good blend you would not want to have quite such a distinct upwards traveling shape on the wing - that will make the blend also try to go upwards when it comes off of the wing.

Instead of blend maybe pushing the pieces through each other, then doing boolean union, then doing a fillet might be easier.

- Michael