The hydraulic systems and components used in aircraft are of central importance to their design. This is a comprehensive introduction to these systems and components and their applications, in which description and analysis are supported by worked examples, exercises, and numerical questions, thus allowing readers to gauge their progress in the subject. The author has divided the book into two main sections: the first introduces aircraft general services, flying control systems, and their common components; the second introduces fluid compressibility and the use of the linear perturbations method to analyze the performance of powered flying controls. Finally, a comprehensive reference list is included to enable readers to increase their knowledge of this field. The overall approach of this book is modular, as it has been developed from courses taught by the author at the University of Salford, where he is Honorary Senior Lecturer in the Department of Aeronautical Engineering.