"Systems of Commercial Turbofan Engines" gives the reader information about the operation of the engine systems, its components and the terminology used throughout the industry. The engine systems are explained by the use of examples from today's engines. So the readers, from aircraft mechanics to commercial pilot, become familiar with the current technology in this field and attains a deeper knowledge of the systems of commercial turbofan engines. To understand the operation of gas turbine engines used in aircraft, it is not enough to understand the basic operation of a gas turbine. It is also necessary to understand the operation and the design of its auxiliary systems. This book is an introduction into the systems of modern commercial aircraft gas turbine engines. It is made for the reader who is familiar with the basic operation of aircraft gas turbine engine.