What is the total number of oxygen masks contained in the PSU?

The total number of oxygen masks contained in the Passenger Service Unit (PSU) is three. This design is standard across many aircraft to ensure that there are enough masks available for passengers in case of an emergency where supplemental oxygen is required. Typically, the PSU is designed to accommodate the oxygen needs of three passengers seated in proximity, thereby providing a safety feature that enhances passenger security during critical situations.

The configuration allows for rapid deployment and ensures that each mask is readily accessible. This helps facilitate efficient response times when an emergency occurs, ensuring that all passengers can secure oxygen quickly and effectively. Understanding this component's purpose contributes to a comprehensive knowledge of aircraft safety systems and their operation.