Just as the airplane has been a defining technology of the 20th century, aerodynamics has been the defining element of the airplane. In ""The Bird Is on the Wing"", Hansen provides an easily understandable introduction to the role of aerodynamics in the design of such historic American aircraft as the DC-3, X-1, and 747. He presents a history of aircraft technology and a collective biography of the scientists, engineers, and designers who created the airplanes. He skillfully guides the reader through the development of such critical concepts as streamlining, flutter, laminar-flow airfoils, the mythical ""sound barrier,"" variable-sweep wing, supersonic cruise, blended body, and much more. Hansen's explanation of how vocabulary and specifications were developed to fill the gap between the perceptions of pilots and the systems of engineers should appeal to all those interested in how human beings have used aerodynamics to move among, and even beyond, birds on the wing.