[JKCalhoun]

You reminded me of "The Great International Paper Airplane Book" (http://a.co/aCbN01n) .. what a classic.

There is a section in the book on the plane that won the duration contest. More or less a rectangular wing as I recall with just enough forward mass to give it forward movement and just enough dihedral to keep it stable.

Edit: found a page where the first image is of that record setting duration flight: http://www.codex99.com/design/the-paper-airplane-book.html