I was flying fro Ontario to San Diego yesterday on TS1 when I spotted multiple airports with the airport code (ex: KSAN) and then the word “APP” afterwords. I checked the airport info and there were either departures, center, and approach from the same person at different airports. What is that supposed to mean?
Here is the answer you are looking for.
You basically answered your own question.
APP next to the airport name signifies that there is an active radar frequency controller (approach, departure, center) and not a tower or ground frequency controller. :)
Pretty much it means the App is running Tower And Ground So tower and ground are unicom but there is someone running Approach/Departure/Center
Dang it @Nathan you beat me to it haa
Same… @nathan 's got the right answer