Activate the helicopter by clicking on the button with the helicopter icon in the combat interface:
You can control the helicopter - to do this, use the movement joystick at the left bottom of the screen (for the PC version of the WASD key) and the shooting button at the right bottom. To use the missiles, press the corresponding button (for the PC version, key R):
At any moment, it is possible to return to control of the ship by pressing the corresponding button of the helicopter while it will be controlled by AI and cover the ship with shooting and MG
