How many minutes of oxygen does the emergency oxygen system provide for ejected aircrew above 10,000 feet?

The emergency oxygen system is designed to provide supplemental oxygen to ejected aircrew members who may find themselves at high altitudes, specifically above 10,000 feet. At these altitudes, the atmospheric pressure decreases, leading to a lower availability of oxygen, which can result in hypoxia or oxygen deprivation.

The system is engineered to sustain the aircrew's oxygen needs long enough to enable safe descent and recovery from high-altitude conditions. Providing 10 minutes of oxygen assures that individuals have ample time to regain control and make decisions about their descent, ensuring a higher likelihood of survival.

In contrast, the other options suggest shorter durations, which may not sufficiently address the needs of aircrew under the conditions requiring emergency oxygen, thereby increasing the risk of hypoxia during critical moments.