What is the first step in the decompression drill?

In any emergency involving cabin depressurization, the priority is to ensure that everyone onboard receives adequate oxygen to breathe. This is why the first step in the decompression drill involves putting on the oxygen mask. The fast response to activate personal oxygen supply helps prevent hypoxia, which can impair a person's ability to think clearly and respond appropriately in an emergency situation.

While other steps in the drill are important, like strapping in or communicating with the flight deck, activating the oxygen mask takes precedence because it directly addresses the immediate need for oxygen in a potentially life-threatening situation. Therefore, prioritizing the donning of the oxygen mask helps ensure that crew members remain conscious and capable of executing further safety procedures effectively.