mayday

Mayday is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.
It is used to signal a life-threatening emergency primarily by aviators and mariners, but in some countries local organizations such as firefighters, police forces, and transportation organizations also use the term. The call is always given three times in a row ("Mayday mayday mayday") to prevent it being mistaken for some similar-sounding phrase under noisy conditions, and to distinguish an actual mayday call from a message about a mayday call.

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