Mayday is an internationally recognized emergency procedure word used as a distress signal in voice radio communications, primarily by aviators and mariners to indicate a life-threatening emergency. The term is repeated three times ("Mayday Mayday Mayday") to clearly signal urgent distress and to prevent confusion with ordinary conversation. It originated in the early 1920s, coined by Frederick Stanley Mockford at Croydon Airport, England, who chose the word because it sounded like the French phrase m'aider ("help me"), reflecting the frequent flights between London and Paris at the time. Mayday replaced the Morse code SOS signal for voice communications because SOS was difficult to distinguish by telephone. The call prompts immediate assistance and coordinated rescue efforts from relevant authorities

. Mayday calls typically include key information such as the station being addressed, aircraft call sign and type, nature of the emergency, weather conditions, pilot’s intentions, location, altitude, fuel status, and number of passengers to facilitate an effective emergency response

. It is important to note that "Mayday" as a distress call is distinct from "May Day," which refers to a traditional European festival marking the beginning of summer on May 1, or the International Workers' Day observed on the same date with labor movement significance