Within approximately how many seconds should passenger oxygen masks deploy after loss of cabin pressure?

Within approximately how many seconds should passenger oxygen masks deploy after loss of cabin pressure?

• A. About 15 seconds
• B. About 60 seconds
• C. About 5 seconds
• D. Immediately

Answer: (A)

When cabin depressurization occurs, the emergency oxygen system is designed so that the masks deploy and oxygen begins flowing within about 15 seconds. This rapid deployment is crucial to prevent hypoxia as the aircraft descends to a breathable altitude. The other timeframes are too short or too long: 5 seconds is faster than the mechanism can reliably release and start oxygen flow, 60 seconds would leave people without adequate oxygen for a dangerous period, and immediately would ignore the small, necessary delay in release and flow initiation.

When cabin depressurization occurs, the emergency oxygen system is designed so that the masks deploy and oxygen begins flowing within about 15 seconds. This rapid deployment is crucial to prevent hypoxia as the aircraft descends to a breathable altitude. The other timeframes are too short or too long: 5 seconds is faster than the mechanism can reliably release and start oxygen flow, 60 seconds would leave people without adequate oxygen for a dangerous period, and immediately would ignore the small, necessary delay in release and flow initiation.