Announcements should be done in whatever languages will serve as many passengers as possible, within reason.

So on a flight from France to Germany, there are likely to be a number of people who don't understand French or German. English is likely to be the language which is understood by the most people who don't speak French or German, and using it will serve a lot of passengers.


For a number or reasons, mostly the British Empire and American influence, English is the most global language. In every area of the world there are countries that speak English, or have the English langaue in their past.

English will likely never be the world's langauge, but in many ways it is the world's second langauge in many places.