Can anyone enlighten me why there is 2xBreak instead of just one like I seem to recall the yanks use? Too smooth for European use?
"Break" is used when you're passing a long message to a pilot and you want to ensure that he/she's receiving it. I'd use it when passing, say, an ARFOR or long NOTAM. I wouldn't want to get to the end only to find that the pilot sez "say again all after ARFOR"!! Also it gives the opportunity for another aircraft to get in with a more important call such as MAYDAY.
"Break break" is used when changing from one aircraft to another. For instance, you acknowldege an aircraft and then move immediately to a second aircraft with an instruction instead of taking you hand off the mike key.