How do you know when to change frequencies when on UNICOM?

Usually ATC will send you a “contact me” when you have to contact them as you are getting in their range. Best thing to do is to wait for that contact me. In some cases, it’s more logical to contact ATC yourself, for example, when you are established on the ILS you can contact Tower yourself, or after you have vacated the runway, you can also contact Ground yourself. More in the video above!