Operation Flashpoint: Dragon Rising

I unlocked this achievement by getting to the control tower.

When you get to the control tower, your character will talk to command saying you have captured the control tower and the achievement should unlock.

NOTE: When the achievement unlocked for me, there were 3 enemies still alive inside the control tower.

Mission: Eagle Offense
Objective:
Take and Hold the Airfield

Once you clear out the airfield, and make your way to the Radar Tower this achievement will unlock.