If you are not using supplemental oxygen what are the restrictions for above 14,000' MSL?

At altitudes above 14,000 feet Mean Sea Level (MSL), physiological effects on pilots become significantly more pronounced due to decreased atmospheric pressure and reduced oxygen availability. Consequently, regulations dictate that if a pilot is not using supplemental oxygen, they cannot operate an aircraft at such elevations.

This restriction is in place to mitigate the risk of hypoxia, which can impair cognitive and physical performance, leading to dangerous flight situations. The lack of oxygen can result in disorientation, loss of consciousness, and other critical issues impacting flight safety. Therefore, the regulation clearly prohibits any flight operation above this altitude without supplemental oxygen, making the first choice the only viable option for safe and responsible flying practices.