Under what circumstances can cabin crew initiate an evacuation without the captain's command?

Cabin crew can initiate an evacuation without the captain's command primarily during situations where the safety of passengers and crew is at immediate risk. Ditching of the aircraft is one such circumstance, as it typically involves a critical emergency that demands swift action to prevent loss of life or serious injury. In this scenario, the crew must act quickly to facilitate an orderly evacuation, as the aircraft's position in water may create rapid dangers, such as capsizing or sinking.

While communication failure or technical malfunctions are serious issues, they do not inherently necessitate an immediate evacuation decision without the captain's directive. These situations may require the cabin crew to assess the environment and maintain communication as best as possible with the captain before proceeding to evacuate. Low fuel warnings also do not typically warrant an evacuation order without the captain's command, as procedures are usually in place to ensure safe landing rather than an immediate evacuation.

Therefore, the urgency and critical nature of ditching substantially justify the cabin crew's ability to act decisively in initiating an evacuation for the safety of all on board.