What command is typically given to signal an evacuation to passengers?

The command "Evacuate, evacuate" is typically used to signal an evacuation to passengers because it is clear, direct, and unambiguous. In high-stress situations such as an emergency evacuation, passengers need instructions that convey urgency and are easily understood without any room for misinterpretation. This phrase provides immediate recognition of the action that needs to be taken.

In contrast, the other options may not effectively communicate the necessity of immediate action. "Safety first" sounds more like a general statement about safety rather than a clear directive for evacuation. "Get out now!" could generate panic and does not specify what to do or where to go, while "Leave the aircraft!" while somewhat direct, lacks the repetitive emphasis that "evacuate, evacuate" imparts. The repetition in the correct phrase reinforces the urgency of the situation and ensures that passengers recognize the importance of following the instruction promptly.