Thank you for giving 6th rank to my design with bird. I think, maybe I need to explain, why I used bird. Well, as I know, birds are really industrious. Their body is warm, and other side wings can make wind. English isnt my native language, thats why I cannot give more detailed information of this idea, but I hope that you got the main point. If you want to see different variants of it, let me know, please. Thank you.