Conceived by chief designer Reinhold Mewes and technical director Erich Bachem, Fieseler's design had a far better short take off and landing ("STOL") performance. A fixed slat ran along the entire length of the leading edge of the long wings, while a hinged and slotted set of control surfaces ran along the entire length of trailing edge. This was inspired by earlier 1930s Junkers Doppelflügel, "double-wing" aircraft wing control surface design concepts.