Thanks, this is exactly what I was looking for. And yes, this is for a single player "campaign" style mission, where I'm scripting and voice acting the radio's/atc stuff.
One note, On my mission, indicator ID 17 didn't work. However, 18 did. I didn't test your mission because I got mine to work with 18, so not sure what happened there. Is there a list of what text is which indicator ID?