To throw another ten-penny-worth into the 'Mayday' language debate...
'M'aider is the infinitive form of the reflexive verb "help me" within French syntax; however, it is not used as a stand-alone imperative command in standard French, but it is so used in some French patois. This has led some etymologists to claim that what the convention really meant was an abbreviation of the phrase, "Venez m’aider" ("Come help me"). "M'aidez" (which is not grammatically correct either in standard French) is considered an acceptable alternative. In both cases, however, mayday must be considered as a rather crude English phonetic representation. It should be also noted that while in English the phrase is only used in distress situation, in French it carries no more sense of urgency than its English translation "help me".
What French people in distress actually shout is, "Au secours!"'
Bottom line...In many (most?) parts of the world a 'Pan-Pan' call will evoke the response, "What?" or something similar.
'Mayday' works every time!
