During which phase of flight are oxygen systems most commonly utilized?

Oxygen systems are most commonly utilized during emergency situations because these scenarios often involve a rapid loss of cabin pressure or situations where supplemental oxygen is required for passenger safety and pilot performance. In emergency situations, such as cabin depressurization, the altitude may increase quickly, leading to hypoxia, where the body does not get enough oxygen. Rapid access to oxygen is crucial in these instances to ensure the safety of everyone on board.

While oxygen systems can be used at various phases of flight, they are primarily designed and frequently deployed in emergencies when the risk of inadequate oxygen supply is highest. In contrast, other phases such as takeoff, cruise, and descent typically operate under normal atmospheric conditions, where supplemental oxygen is not usually necessary unless the aircraft is flying at higher altitudes or if specific regulations or health conditions dictate otherwise.