The direction of movement

During directional horizontal flight the rotor is tilted slightly forward, to not only provide lift, but to move the helicopter in the air. To the rotor leaned forward, the angle of attack of each of blades increases, when they appear at the rear and decreases when the front. As a result the lifting force increases and decreases behind the front, tilting the rotor forward.
The rotor can be tilted in other directions, causing the helicopter to move backward or to the side. For example, for movement to the right increases the lifting force to the left, tilting the rotor to the right. The pilot controls the tilt of the rotor using cyclic pitch lever.
When the helicopter hangs in the air, starts to move forward, it can bend on one side. This is because due to the flow of air towards the helicopter speed is increased until the air vane, which rotates forward, while the speed of the blade, which rotates back decreases. Thus, the lifting force is usually large with one side of the helicopter and less on the other. Action to overcome this problem the blades are mounted on hinges, which makes them more flexible and makes be bent slightly upwards during forward rotation. This leads to a reduction in lifting force and counteracts its increase due to an increase in the speed of the blades relative to the air. As a result, the helicopter leans to one side.