Mayday

Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me".

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

Read more about Mayday:  Mayday Calls, History, Other Urgent Calls