Codex on the Flight of Birds of a kite as seeking a wind current. When the winds are high, one will see the bird very high in the sky, but when the winds are low, the bird stays closer to the ground. Leonardo describes how a bird rests in the air, after flapping its wings to gain altitude, by gliding downward to the ground. Folio 6 contains multiple diagrams of birds flying and their bone structure, and all of the commentary is on flight and how birds fly the way that they do. Leonardo starts off by describing how a bird ascends or descends in different
Flying wing the payload and a long span for high efficiency, while the high-speed wing would have a thin, sharp-edged airfoil and a shorter span for low drag at supersonic speed. Some related aircraft that are not strictly flying wings have been described as such. Some types, such as the Northrop Flying Wing (NX-216H), still have a tail stabilizer mounted on tail booms, although they lack a fuselage. Many hang gliders and microlight aircraft are tailless. Although sometimes referred to as flying wings, these types carry the pilot (and engine where fitted) below the wing structure rather than inside it, and so