That’s the story I’ve heard. The term “Mayday” also comes from the French. More to the point, it comes from an English speaker’s mishearing of French. The original phrase is ’M’aidez!’ meaning ‘Help me!’ To an English speaker, this sounds like the words ‘may day.’ A French speaker could also say "aidez moi,’ which doesn’t sound like anything in English. If your plane is spinning, though, you probably want to say what’s quickest.
John Zakour and Scott Roberts