This document covers information concerning the use of oxygen when flying into and out of high elevation airports for both pressurized and non-pressurized aircraft. Oxygen requirements for pressurized aircraft operating at high altitudes have for decades emphasized the potential failures that could lead to a loss of cabin pressurization coupled with the potential severe hypoxic hazard that decompressions represent. This document is intended to address the case where the relationship between cabin and ambient pressures are complicated by operations at high terrestrial altitudes. Operators who fly into these high-altitude airports should address the issues related to this environment because it carries the potential for insidious hypoxia and other conditions which can affect safety. It provides information to consider in developing operational procedures to address hypoxia concerns consistent with regulatory mandates. In some sections, procedures are discussed that may mitigate the deleterious effects of hypoxia in a non-flight regime yet still have the potential to represent risk factors associated with flight operations. All the information is provided as a framework for potential oxygen management and other procedures to facilitate responsible practices and facilitate compliance with existing regulatory requirements. This document cannot address every type aircraft pressurization system, oxygen system or operational condition the flight may encounter. Any threat or hazard not discussed in AIR6829 should be brought to the attention of the OEM, the regulatory authority and the flight operations department for proper guidance. The number of high elevation airports (greater than 8000 feet MSL) being constructed worldwide is increasing, and there is a need to provide additional guidance on oxygen use for flight operations which are covered in various documents and manuals (AFM, FCOM, SMS) as approved by national authorities. This document intends to address oxygen considerations at high altitude airports. This AIR will provide safe guidance based on physiological requirements and list best operating procedures/practices intended to prevent subtle hypoxia. This will ensure the safety of flight is not compromised due to oxygen deficiencies that may arise in this unfamiliar area of flight operations. This document will address physiology, system, equipment operations/limitations, and flight operations to provide a broad body of information to aid in adhering to current regulations. In some cases, there will be operational issues without an obvious link to oxygen requirements, but which could have indirect consequences. This document will attempt to identify these issues in an SMS construct. Nothing herein takes precedence over an aircraft OEM or an approved AFM/POH.