How long does cabin emergency oxygen last on the Boeing 787?

How long does cabin emergency oxygen last on the Boeing 787?

• A. Twenty-Two Minutes
• B. Fifteen Minutes
• C. Thirty Minutes
• D. Forty-Five Minutes

Answer: (A)

Emergency oxygen duration is the period after a loss of pressurization during which the cabin oxygen system can continuously supply breathable oxygen to all masks. On the Boeing 787, that duration is 22 minutes. This length is chosen to ensure there is ample oxygen for the entire cabin as the aircraft performs a safe, controlled descent to a breathable altitude and for the crew to manage the emergency. Shorter durations, like 15 minutes, are common on older designs and would leave less margin for descent and procedures, while longer durations aren’t required for certification and add unnecessary weight. So the 22-minute value reflects the 787’s oxygen system capacity and the operational need for a reliable oxygen supply during an in-flight depressurization.

Emergency oxygen duration is the period after a loss of pressurization during which the cabin oxygen system can continuously supply breathable oxygen to all masks. On the Boeing 787, that duration is 22 minutes. This length is chosen to ensure there is ample oxygen for the entire cabin as the aircraft performs a safe, controlled descent to a breathable altitude and for the crew to manage the emergency. Shorter durations, like 15 minutes, are common on older designs and would leave less margin for descent and procedures, while longer durations aren’t required for certification and add unnecessary weight. So the 22-minute value reflects the 787’s oxygen system capacity and the operational need for a reliable oxygen supply during an in-flight depressurization.