PSU is also known as COS-Cabin Oxygen System (chemical oxygen).

PSU is also known as COS-Cabin Oxygen System (chemical oxygen).

• A. False
• B. It uses non-chemical oxygen
• C. It is a different system than the PSU
• D. True

Answer: (D)

Understanding how cabin oxygen is delivered helps. The Cabin Oxygen System (COS) refers to the overall setup that provides oxygen to passengers when the masks drop, and it uses chemical oxygen generators to produce that oxygen. The Passenger Service Unit (PSU) is the panel installed at the seat that houses the oxygen mask outlets and related components within the COS. Because the PSU is the part of the cabin system through which oxygen reaches passengers, training sometimes refers to the PSU as the COS-Cabin Oxygen System. So the statement aligns with how these terms are used together in the context of the oxygen delivery system.

Understanding how cabin oxygen is delivered helps. The Cabin Oxygen System (COS) refers to the overall setup that provides oxygen to passengers when the masks drop, and it uses chemical oxygen generators to produce that oxygen. The Passenger Service Unit (PSU) is the panel installed at the seat that houses the oxygen mask outlets and related components within the COS. Because the PSU is the part of the cabin system through which oxygen reaches passengers, training sometimes refers to the PSU as the COS-Cabin Oxygen System. So the statement aligns with how these terms are used together in the context of the oxygen delivery system.