When an aircraft or vessel was in distress, the radio operator used the term ''Mayday'' to advise other carriers in the area. This word is derived from the French sentence ''Venez m'aider'' (Come help me). The French sentence was shortened to ''Mayday'' as an international term for distress.
In 1927, the International Radio Telegraph Convention legitimized this purpose. Nowadays, it is used to signal a life-threatening emergency primarily by mariners and aviators, but in some countries local organizations 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 similar-sounding phrases under noisy conditions, and to distinguish an actual Mayday call from any other communications.
- Source 1: Etymonline Online Etymology Dictionary