How Helicopters Work
Actually the main rotor does all of the flying. When it rotates it cuts the wind and generates force to push the helicopter upward. You can increase or decrease this force by using an input called collective input. When this force becomes greater than the weight of the helicopter, the helicopter will start to go up, and when this force becomes less than the weight, the helicopter will start to go down.
Ok so now you know how helicopters go up and down, but do you know how they move forward? Well, this is also done by the main rotor. Think that the direction of main rotor force is a bit tilted to forward. By this direction of force, the force has two parts - one in up direction and one in forward direction. So the force to up is used to compensate the weight and the force to forward is used to move the helicopter forward.
Good, so how we can tilt the direction of main rotor force? Yes, there is an another input called cyclic input, this one is used to tilt the direction of main rotor force. This input is a two dimensional input i.e. by this you can give input to forward, backward, left and right. Be careful that the cyclic input is very sensitive, so change it slowly.
The more the direction of main rotor force is tilted to forward, the more the force to forward will act and the less the force to up will act. So remember that when you tilt the direction of main rotor force to froward, you have to increase the collective input so that it can provide enough force to up to compensate the weight of helicopter. When you start moving forward, an additional force will be applied to your helicopter to backward direction, it is due to the wind flow. This wind force will be compensated by the main rotor force to forward. The faster you go forward, the more wind force will be applied to backward direction. So tilt the direction of main rotor force to forward more to compensate more wind force as you go faster.
Ok, almost done. So now we know the basics in theory, for practical let's see the following videos from Helicopter Race. Practically there are some more factors on flying. You can try it yourself by downloading the game.
And that's all! . . So from now you are a pilot :D