You guys know the search function is still not working?
He came back and had no other way to find the information other than authoring a thread.
Capturing an airbase requires one to drop troops in the nearby town close enough that they can run to an underground bunker that exists right under the flag.......which must be white to capture the base.
Capturing a "V field" or "tank field" is similar except there is no town.
Instead, there is a green mound near the tower that has an entrance to a small bunker.
The significance of these bunkers is that a person who has chuted out and is on foot can also access the bunkers and sit inside to shoot the enemy grunts who attempt to run in.
Even though these are "bunkers" you are not safe inside from "splash damage" caused by both bombs and HE tank rounds.