What is the immediate action required of crew when a decompression occurs?

• A. Don oxygen masks, secure themselves, and begin cabin-wide checks and descent planning if needed
• B. Initiate the emergency landing checklist immediately
• C. Notify ATC and remain seated
• D. Open the cabin doors to equalize pressure

Answer: (A)

When a decompression happens, the immediate priority is to protect the crew from hypoxia and establish control of the situation. Donning oxygen masks right away ensures you and your colleagues have a reliable supply of oxygen, which is critical because at altitude air becomes too thin to sustain normal thinking and coordination if oxygen is not provided. Once you’re on oxygen, you can secure yourself so you’re able to move and work, then start cabin-wide checks to confirm that passengers are also getting oxygen, identify any injuries or hazards, and confirm the status of equipment and the cabin. Simultaneously, you begin descent planning to reach a lower altitude with breathable air, coordinating as needed with the flight deck and air traffic control. This order—oxygen for the crew, securing yourselves, then conducting cabin checks and initiating descent—addresses the most urgent danger first and lays the groundwork for safely managing the rest of the emergency. Opening cabin doors in flight is dangerous and not permissible, and actions that delay establishing oxygen and descent planning can leave passengers and crew at greater risk.