In the IAC Cabin Alt Msg or Emergency Descent Procedure, what is the required initial action?

• A. Oxygen Masks / Smoke Goggles - DON, Set TO 100%
• B. Crew Communication - ESTABLISH
• C. Both A and B
• D. Evacuate

Answer: (A)

The first priority in a cabin altitude warning or emergency descent is to ensure everyone aboard has reliable oxygen and protection from smoke. Donning the oxygen masks and smoke goggles and setting the oxygen to 100% delivers the highest and quickest protection against hypoxia and smoke exposure, keeping crew and passengers conscious and able to manage the situation as the descent begins. Establishing crew communication and coordinating actions are important, but they come after ensuring immediate oxygen supply. Evacuation is not the initial step because the aircraft typically continues flying to a safe altitude before considering exit from the cabin; starting with oxygen and eye protection is the fastest way to maintain operational capability and safety.