COMIn a nutshell, listen to ATIS (automatic terminal information service) - it's an automatically generated message that tells you atmospheric pressure, winds, visibility, etc.
Then for departure, contact these COM channels using their corresponding frequencies:
* DEL (delivery) - request approval to fly to your destination and to start engines
* then GND (ground) for pushback and to taxi out
* then TWR (tower) to enter the runway and takeoff
* then DEP (departure) to leave the airport space
NAVThe VOR is for navigation. In the US they usually have a 130 mile range (depending on your altitude). They're usually located somewhere near the center of the airport. The VOR signal makes the vertical needle on your indicator go side to side.
The DME is also for navigation but for short range - like within 18 miles or so. It tells you if you're at the right altitude (and therefore right glide slope) for landing. The DME signal makes the horizontal needle on your indicator go up and down.
The airport VOR (the 130 mile range one) helps you find the airport. The runway VOR/DME combination (the short range one) helps you line up and land on the runway it's associated with.
ADF is a much simpler system than VOR. ADF is a simple AM radio signal and the needle on your indicator will point in the direction of the ADF beacon.
TACAN is a military (and more accurate) alternative to the VOR/DME setup. VORTAC is just a combination of VOR and TACAN.
A few resources...Have a look at this for an explanation of the different Air Traffic Controllers (ATC) and what they're for:
https://www.vatsim.net/pilot-resource-c ... cd-gnd-twrHave a listen to live communications from the various controllers so that it becomes something real to you and not just something to memorize:
https://www.liveatc.net/search/?icao=ksfo