This book explains in simple terms the fundamental principles of flight and the basic aerodynamic factors affecting radio controlled flying models. Neither mathematics or higher physics is required in order to understand how and why model aircraft behave and sometimes misbehave in the way that they do. A little theory can be turned to practical advantage, enhancing model performance and the enjoyment experienced by the model flier. Although the book was written primarily for fliers of conventional radio-controlled models, the principles apply to other aspects of model flying such as free flight, control-line, helicopters and gliders.