There are a number of ATC programs available to flight simulation. One of the popular ones is Radar Contact, which was firstly released 21 years ago. Recently, its developers announced to give the program away for free from January 1st, this year. If you are not aware of it, you can get your copy from here.
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That is pretty cool that it is free now, however I much prefer Vatsim (which is also free), where you actually talk to live atc (human) controllers.
It brings realism to a whole new level, when you have a “live” person giving you IFR clearances, radar vectors, taxi/takeoff/landing clearances.
Not to mention flying with other pilots online and hearing their communications too. For anyone that has never flown online before, I highly recommend checking out BVA at the following link, http://www.bvartcc.com/Home.aspx
This is how I got started, and I learned so much from them, that it helped me out with my PPL and IFR in real life. Plus you get some free scenery, and they have free VRF and IFR flight lessons (called Pilot ratings program) It is fabulous!
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