Aimed at those with no scientific background, this book is written for the amateur enthusiast, the professional pilot, the aircraft technician and the aeronautical engineer. It gives an insight into the principles of aircraft flight, but is not a mathematically based text book and no mathematical knowledge is assumed beyond elementary algebra. The book proceeds from the basic fundamentals of flight such as aerodynamic force, pressure and energy, working out aerodynamic forces, boundary layers and drag and leads to the discovery of the aerofoil shape. It goes on to describe physical modelling and the effect of scale, practical aerofoils in real flow situations, supersonic aerofoils and other more complex effects found to affect wing shape.