Immediately after Mission 6: Special Missions HQ begins, you can see some surveillance cameras. Hide behind a wall, and release your Tri-Rotor drone. Steer it to the camera, and shoot a sticky shocker dart. This will destroy the camera, and you will get the "Tri-Rotor Functionality" achievement. Note: You can purchase the Tri-Rotor drone on your airplane (headquarters) for $72,000. It is not a requirement to upgrade it to get this achievement.