In order to advance the progress in the mission, you have to clear and capture enemy airbases & FARPs.
Airbase: You need to locate and destroy all units and target buildings on or in close vicinity to the airbase. Once clear you will get a message stating that. When its cleared a helicopter need to fly in ground troops, but beware that there could still be enemy forces close by but not directly on the airbase. There may be several target buildings, but not more then three of each.
FARPS: You need to locate and destroy all units on or in close proximity to the FARP, once clear you will get a message and its time for the helicopters to bring in ground troops.
When an airbase/farp shows clear, there might still be enemy forces around the area but outside the capture area of the airbase/farp in question.
Log into SRS and Discord, make your presence known and ask if you need help!