What actions are taken for a cabin depressurization event in flight?

• A. Don oxygen masks, initiate descent to a safe altitude, inform cabin crew, and follow QRH.
• B. Increase air conditioning flow.
• C. Shut down engines.
• D. Ignore and continue flight at cruise.

Answer: (A)

In a cabin depressurization, the priority is to keep people breathing and get the aircraft to a breathable environment as quickly as possible, while coordinating the crew and following the established procedures. The correct sequence is to don oxygen masks, begin an emergency descent to a safe altitude, inform the cabin crew, and follow the QRH. Providing oxygen immediately prevents hypoxia as cabin pressure rises, and an accelerated descent reduces the cabin altitude to a level where oxygen is sufficient for most occupants. Notifying the cabin crew ensures they can secure the cabin, assist passengers, and prepare for possible injuries, while following the QRH guarantees aircraft-specific steps are taken correctly, including any required checks and communications with ATC and finding a suitable place to land. Increasing air conditioning flow won’t address the lack of oxygen, shutting down engines isn’t part of the depressurization procedure, and ignoring the situation to continue at cruise would put everyone at significant risk.