How do you defeat the big helicopter in bionic commando?

Its simple just follow these steps:

1) use the weapon supplied

2) go to high point

3) zoom in using the weapon and keep holding the fire button in zoom mode(press and hold left mouse button). You will see 3 circles around the center point.

4) now aim the Buraq helicopter until the 3 circles gets locked on to the target.

5) press fire to fire the weapon. The missiles will hit the target.

6) Polycrafts will appears in the middle. Destroy them using the same method. It is important to destroy all the Polycrafts first and then get back to the Helicopter.