What is the protocol for unpressurized flights above 10,000 feet?

The correct approach for unpressurized flights above 10,000 feet requires that oxygen masks be utilized by both crew and passengers. This protocol is essential to ensure that all individuals onboard are adequately protected from the potential effects of hypoxia, which can occur at higher altitudes due to lower atmospheric pressure and reduced oxygen levels.

When flying at altitudes above 10,000 feet, the body begins to experience physiological changes, and the risk of hypoxia increases as oxygen availability diminishes. The use of oxygen masks allows both crew and passengers to maintain normal oxygen levels, ensuring safety and preventing any adverse health effects during the flight.

The other options suggest either the unnecessary storage of oxygen masks or that only crew members should use them, which does not align with safety protocols. Additionally, indicating that no special procedures are needed fails to acknowledge the significant health risks associated with high-altitude flights without pressurization. Therefore, using oxygen masks for everyone on board is a critical safety measure.