What is a potential risk of flying at altitudes above 10,000 feet without supplemental oxygen?

Flying at altitudes above 10,000 feet without supplemental oxygen can lead to cognitive impairment due to the decreased partial pressure of oxygen in the cabin environment, which can affect brain function. At higher altitudes, the availability of oxygen is reduced, which can result in hypoxia—a condition characterized by insufficient oxygen reaching the brain. This can manifest as confusion, difficulty concentrating, impaired judgment, and slower reaction times, all of which can significantly impact a pilot’s performance and decision-making abilities.

Although dehydration can occur during flights, it is not the primary concern related to high altitude and lack of oxygen. Increased visibility may be a misconception, as altitude itself does not guarantee clearer sight but rather changes the atmospheric conditions. Enhanced physical performance is not supported, as lower oxygen levels can lead to fatigue and decreased physical capabilities. Thus, cognitive impairment stands out as the most pertinent risk when flying above 10,000 feet without supplemental oxygen.