Liquid supply systems for breathing oxygen for the crew and/or passengers of transport aircraft require design and installation considerations, which are detailed herein. AIR 825, Oxygen Equipment for Aircraft, contains general information on determination of breathing oxygen requirements and equipments for the crew and passengers of transport category aircraft. This document covers the more specific requirements for either a 70 or 300 psig liquid oxygen system. The standard 70 psig nominal pressure is recommended for use except in cases of excessive pressure drop, flow requirements, and some continuous flow regulators which may require the 300 psig nominal pressure system. AS 861, Minimum General Standards for Oxygen Systems and AIR 822, Oxygen Systems for General Aviation Aircraft, also contain general applicable information. NOTE: When Military Specification components are referenced in this document, it is intended that this be interpreted as a guide and the components functionally equivalent to these units may be used.
