1990s, jayteeto plus puma and two colleagues plunging into jungle in Belize. Crewman shouts "MAY DAY MAY DAY MAY DAY VIPER 2 GOING IN!". Army signaller writes it all down as is his brief. After some head scratching, he can't figure it and asks his corporal what a mayday is?
Lesson learned, if a police control room is providing flightwatch, make sure they know the jargon. Did the cops get a call out? For future ops, it might be worth briefing the crew in advance to make a call if you are busy fighting the aircraft????
For the record, the emergency was caused by the tail rotor driveshaft and I was WAY too busy to think about the xxx radio........