An authentic Swiss Army Manual 56.113d. Das Flugzeug; The Plane. 1960. Six chapters cover the general principles of aircraft. Main concepts of flying, basics of the theory of flight, construction of the plane, the engines, additional facilities, and Plane and Sound Velocity. The book is completely written in German. 8 1/4" X 5 3/4". Heavy board for cover. The book is in very good condition. I used Google translate.