What altitude range necessitates supplemental oxygen according to part 91 regulations for crew members?

Supplemental oxygen is required for crew members operating at specific altitudes to ensure safety and maintain cognitive function in the lower oxygen environment of higher altitudes. According to part 91 regulations, crew members must use supplemental oxygen when flying at altitudes between 12,500 feet and 14,000 feet for more than 30 minutes. This range is crucial because the ambient pressure decreases significantly at these altitudes, leading to a reduction in the amount of oxygen available for breathing, which can impair performance and pose serious health risks.

At altitudes above 14,000 feet, the regulations become even more stringent, requiring supplemental oxygen for all crew members at all times. This distinction ensures that crew members are adequately protected from the physiological effects of hypoxia, which can occur when there is insufficient oxygen for the body’s needs, especially when exposed to high altitudes for prolonged periods.

Thus, the altitude range that necessitates supplemental oxygen for crew members according to part 91 regulations is specifically between 12,500 and 14,000 feet, ensuring that safety protocols are firmly in place to guard against potential altitude-related complications.