FC,. .. .Not surprising since all three distress/urgency calls are derived from French words:. .. .MAYDAY - m'aidez (help me). .. .PAN PAN - panne (a breakdown). .. .SECURITE - sécurité (security). .. .SECURITE is not used in aeronautical communciations (at least - it isn't in North America). It is used by vessel captains or the coastguard to broadcast messages concerning safety of navigation. See for example <a href="http://www.tc.gc.ca/marinesafety/tp/tp9878/tp9878e.htm" target="_blank">Transport Canada</a> or. . <a href="http://www.navcen.uscg.gov/marcomms/gmdss/dscproc.htm#Safety" target="_blank">US Coastguard</a> . .. .I42