When operating a passenger oxygen mask, what is the correct sequence?

• A. Instruct the passenger to place the mask over nose and mouth, tighten the strap, and breathe normally while securing the mask.
• B. Secure the mask on yourself first, then the passenger.
• C. Remove the mask after a few breaths.
• D. Place the mask under the chin.

Answer: (A)

When a passenger oxygen mask becomes available, the priority is for the passenger to self-apply it quickly and correctly. The correct sequence is to place the mask over the nose and mouth, secure the elastic strap so it fits snugly, and then breathe normally. This order ensures the mask seals properly to deliver oxygen immediately and allows the passenger to continue breathing without panic. The other options either describe placing the mask in the wrong position or delaying oxygen delivery, or involve actions that aren’t appropriate for a passenger to perform (such as doing the securing for someone else first).