With the standard small O2 bottle installed in the nose, how many minutes of oxygen can be supplied to all crew and passengers?

• A. 5 minutes
• B. 10 minutes
• C. 15 minutes
• D. 20 minutes

Answer: (B)

The question tests how long the aircraft’s standard oxygen system can feed everyone on board. The standard small bottle installed in the nose is sized to provide oxygen to all crew and passengers for about ten minutes, using a regulated flow that delivers breathable oxygen to every occupant for that period. This duration is set so there’s enough time to initiate an emergency descent and don oxygen as needed after a loss of cabin pressure. If you used a larger bottle, or a different regulator, the available time would be longer; with a smaller bottle or higher flow, it would be shorter.