What is the default setting for the quick don oxygen masks?

The default setting for the quick don oxygen masks is indeed 100%. This setting is designed to deliver pure oxygen to crew members quickly and efficiently during emergencies, ensuring a rapid response in situations where cabin altitude is compromised or there is a loss of cabin pressure.

Opting for 100% oxygen provides the highest possible concentration of oxygen to the wearer, which is crucial for maintaining consciousness and preventing hypoxia at high altitudes. This is particularly important because any delay in receiving adequate oxygen can lead to serious health issues for crew members who are needed to manage the situation effectively.

Other settings, like Normal or Emergency, may not provide the immediate and pure oxygen needed in critical situations, while Auto is not a standard term for oxygen mask settings in this context. The focus on 100% ensures that crew members are equipped to respond optimally under the pressurized conditions that may arise during an inflight emergency.