Given the times we’re in, this may come in handy.
Wiki:
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 its being mistaken for some similar-sounding phrase under noisy conditions, and to distinguish an actual mayday call from a message about a mayday call.[…]
The “mayday” procedure word was originated in 1923, by a senior radio officer at Croydon Airport in London. The officer, Frederick Stanley Mockford, was asked to think of a word that would indicate distress and would easily be understood by all pilots and ground staff in an emergency. Since much of the traffic at the time was between Croydon and Le Bourget Airport in Paris, he proposed the expression “mayday” from the French m’aider (‘help me’), a shortened form of venez m’aider (‘come and help me’). It is unrelated to the holiday May Day.
Before the voice call “mayday”, SOS was the Morse code equivalent of the mayday call. In 1927, the International Radiotelegraph Convention of Washington adopted the voice call mayday as the radiotelephone distress call in place of the SOS radiotelegraph (Morse code) call.
May be or May be not.