Originally Posted by
Scott Pilgrim
Not strictly true. In terms of air/ground communication, ICAO requires thus...
"The air-ground radiotelephony communications shall be conducted in the language normally used by the station on the ground or in the English language.
The English language shall be available, on request from any aircraft station, at all stations on the ground serving designated airports and routes used by international air services."
It should state in the country's AIP if English is not available at an airfield/area, but there is no requirement for English if it's not an international route or destination.
There are also a number of 'official' ICAO languages.
Very true. I used to work "with" [aka talk to] military ATCOs in France. Some of them spoke very little English at all, as we validated when they did a liaison visit to RAF West Drayton.