How many oxygen flow indicators are present per mask in the cabin O2 system?

How many oxygen flow indicators are present per mask in the cabin O2 system?

• A. One Indicator Per Mask
• B. Two Indicators Per Mask
• C. Three Indicators Per Mask
• D. Four Indicators Per Mask

Answer: (A)

Oxygen flow indicators are positioned to confirm flow for each individual mask. The cabin O2 system feeds each passenger mask along its own line, so you only need one visible indication per mask to show that O2 is flowing to that seat. Having multiple indicators on a single mask would be redundant and potentially confusing, since there is a single flow path per mask and a simple yes/no indication is all that’s needed. Therefore, each mask has one oxygen flow indicator.

Oxygen flow indicators are positioned to confirm flow for each individual mask. The cabin O2 system feeds each passenger mask along its own line, so you only need one visible indication per mask to show that O2 is flowing to that seat. Having multiple indicators on a single mask would be redundant and potentially confusing, since there is a single flow path per mask and a simple yes/no indication is all that’s needed. Therefore, each mask has one oxygen flow indicator.