If the aircraft is climbing above 14,000 feet, what oxygen level is required for the crew?

At altitudes above 14,000 feet, regulations and safety protocols dictate that crew members must utilize 100% oxygen to ensure they are adequately supplied with the necessary levels of oxygen for cognitive and physiological function. This requirement is crucial because, as altitude increases, the partial pressure of oxygen decreases, which can lead to a significant risk of hypoxia.

Providing 100% oxygen helps to mitigate the risk of impaired performance and adverse health effects for crew members, ensuring they can maintain situational awareness and effectively manage aircraft operations. Therefore, adherence to this requirement is essential for flight safety in higher altitude environments where the aircraft may be operating.