Where does the On-Board Oxygen Generation System (OBOGS) hold extra air?

The On-Board Oxygen Generation System (OBOGS) holds extra air in a plenum. The plenum serves as a chamber or compartment that allows the system to collect and distribute oxygen efficiently. In aircraft, this system is designed to generate oxygen for the crew and passengers while flying at high altitudes where the ambient air pressure is insufficient for breathing.

The design of the plenum ensures that the generated oxygen can be stored temporarily before being distributed to the users, maintaining a ready supply of oxygen as needed. This is vital for ensuring that all personnel have access to breathable air, especially in emergency situations or at altitudes where supplemental oxygen is required.

While other choices reference components or locations associated with airflow or storage, they do not accurately describe the specific role of the plenum in the OBOGS.