ATC in Microsoft Flight Simulator X stands for Air Traffic Controller.
At an airport with ATC use the radio to contact ground and ask for taxi instructions.
A reinstall/repair may be needed also check your sound card settings in the flight sim soundf settings as theory frequently rest to default which knocks out ATC sound files
Yes (2017) steam edition also allow for multiplayer - game spy no longer works in the original set up. Many join flight sim networks and use their client for accessing flight and atc
You can have tower view (keys listed in view mode). The tower was useful in GameSpy multi player mode. This is no longer available. If you want ATC functions then consider on line flight communities like steam,ivao or vatsim. These have dedicated ATC clients plus offer training before you are are aloud live interaction
* ALL TERRAIN CYCLE
ATC stands for Athletic Trainer Certified
Almost all do. I'm not sure about USB headsets, because I use a Senheiser pair that have a jack for Sound and one for Mic. I recommend Senheiser if you don't have a pair already. P.S. If you don't know, GameSpy (FSX Multiplayer) is the place where you can talk to ATC and fly with real people.
Automatic Temperature Control.
Alcohol Type Concentrate
During IFR flight, ATC will dictate cruising altitude.
When you are in multiplayer, make sure you are tuned into the right frequency, then press and hold Caps Lock to talk. When you see your Caps Lock light on, that means you are transmitting on your selected frequency.
"air traffic controller" a clever name for the device taken from aviation.