This report provides information on the design and use of aircraft oxygen systems. It explains the physiological oxygen requirements of the human body in both a normal environment and in an hypoxic environment. It includes an overview of the continuous flow, demand and pressure demand, and liquid oxygen systems. A basic understanding of how each system operates is then specifically addressed in its own titled section. The charts, tables and schematics provide a specific example of a theoretical oxygen system design and the calculations shown how that system would meet the regulations established by the FARs. A comprehensive overview of the theoretical oxygen requirements of the human body at altitude is also provided. A detailed list of specifications and standards applicable to aircraft oxygen systems is included.