How do the passenger oxygen masks operate?

The correct operation of passenger oxygen masks is represented by a constant flow design. This type of system delivers a continuous flow of oxygen to the user, which is critical in situations where cabin pressure may be compromised, such as during a rapid decompression event. In these scenarios, the ability of the masks to provide a steady oxygen supply ensures that passengers receive enough oxygen to breathe safely.

In contrast to other designs like demand-controlled activation, which only releases oxygen when the user inhales, or manual switch activation, which requires a passenger to actively turn on the oxygen supply, the constant flow design simplifies the process for passengers. They can simply don the mask without needing to adjust settings or worry about timing their breaths. This reliability is especially beneficial in emergency situations, allowing for immediate access to oxygen without delay.

Quick-donning styles, while providing user-friendliness, do not reflect the primary respiratory function of the masks in terms of operating principles compared to a constant flow system. Thus, the constant flow design efficiently meets the safety requirements for delivering oxygen in-flight emergencies.