When the passenger O2 switch is in the auto position, when is oxygen supplied to the passenger outlets?

• A. When the cabin altitude exceeds 13,500 feet
• B. When the cabin altitude exceeds 15,000 feet
• C. When the cabin altitude exceeds 10,000 feet
• D. When the cabin altitude exceeds 8,000 feet

Answer: (A)

In auto, the passenger oxygen system uses a cabin altitude sensor and automatically feeds oxygen to the passenger outlets when the cabin altitude climbs above a set threshold. That threshold for this aircraft is 13,500 feet, so once the cabin altitude exceeds that level, oxygen is supplied to passengers. The system is designed to provide oxygen only when needed to prevent hypoxia as altitude increases, conserving oxygen when altitude is lower. You can still override by selecting ON to keep oxygen flowing regardless of altitude, or OFF to stop it.