As of recently, IFATCA has developed the Speak English Program (SEP) for air traffic controllers and assistant controllers who are members of their associations.
The program is run by air traffic controllers, who volunteer to hold sessions with their colleagues from around the world. The sessions usually last an hour and in one session there are three, at most four air traffic controllers from all over the world who talk in English about different topics.
If you are interested in participating in this program, either as a facilitator or a student (participant) in order to maintain conversational English, please apply to the e-mail address president@zklm.org.
More information at https://www.ifatca.org/sep/