What are the oxygen requirements when operating at cabin pressure altitudes above 15,000 feet MSL?

When operating at cabin pressure altitudes above 15,000 feet Mean Sea Level (MSL), the requirements for oxygen use become critical for the safety and well-being of both the flightcrew and passengers. At these elevations, there is a significant decrease in the partial pressure of oxygen in the atmosphere, which can lead to hypoxia if supplemental oxygen is not provided.

Choosing to provide supplemental oxygen for both the flightcrew and passengers ensures that everyone on board has the necessary oxygen supply to maintain physiological functions and cognitive abilities. Hypoxia can impair an individual's capacity to function, potentially jeopardizing the safety of the flight.

While it is true that the flightcrew must have oxygen available to effectively manage the flight, the requirement extends to passengers as well when operating above 15,000 feet. This is particularly important since passengers are not as trained to recognize or respond to the early symptoms of hypoxia as the flightcrew. Therefore, ensuring that both groups have access to supplemental oxygen aligns with established safety protocols and regulations in aviation operations.