Hi,
I have this very simple model aa.skp (168.0 KB)
How do I connect the edges A, B, C and D with a plane? I think it will not possible to make a single plane that covers all these points, so how can I make the most beautifull plane that fully connects all those edges? I would like to make this as aerodynamically as possible so if it could be a smooth surface it would be nice.
Hello. First things first. I almost lost your model because it was about to fall into the endless sky! 
There. Now it’s better.
There are several ways you can achieve what you want. But note, that whatever you do, you’re going to have a curved surface, not a flat plane. Here’s a slow-paced, plugin-free way. I like to call this method “weaving” because it looks similar to how a spider weaves its web. When you’re done, pick the Eraser Tool, hold down CTRL and pass over the drawn edges to smooth them. Cheers! 
I really liked your way! Really easy and super super handy! The only “problem” is that if I have a more complex surface I would have to create lines for each plane I need to cretate. Anyway,your idea is very good! If no other better solution is presented I will accept your response, thanks a lot my friend!
You’re welcome. For relatively simple curved geometries this is a good approach. If you have something more curvy and organic, your best bet is to use the plugins such as Curviloft or Soap Skin & Bubble.
Great man I was not aware of those plugins, THANKS A LOT MY FRIEND!
