AMT 2104

It provides lift, which can be employed to keep the aircraft airborne and to provide thrust. It can also counteract torque .

Single main rotor helicopters are the most common type of helicopter. They need an anti-torque device (tail rotor or other anti-torque system) to counteract the twisting momentum produced by the main rotor, which is powered by one or more engine(s).

has two main rotor systems and no tail rotor. Usually, the rear rotor is mounted at a higher position than the front rotor, and the two are designed to avoid the blades colliding, should they flex into the other rotor’s pathway.

are two main rotors mounted on one mast, sharing the same axis of rotation but turning in opposite directions, one on top of the other.

A helicopter with two rotors turning in opposite directions and mounted on two masts slightly inclined towards each other so that the blades intermesh (without colliding).

two horizontal, counter-rotating rotors are mounted side-by-side on a helicopter (or transverse rotorcraft). The side-by-side configuration is one of the possible flight configurations of a tilt-rotor aircraft when the rotors are in the vertical position to provide vertical lift.

The rotors are mounted at the edge of the wings, on nacelles that rotate in order to transition the rotors from the vertical position (to provide vertical lift like a side-by-side rotor configuration helicopter) to the horizontal position (where they provide horizontal lift, or thrust, just like in airplanes).

NOTAR (no tail rotor) is a helicopter system that avoids the use of a tail rotor. uses jet thrust rather than blades to provide directional stability and reduce noise, providing the world's quietest helicopters

changes the tilt of the main rotor for control about the longitudinal axis (roll) and lateral axis (pitch).

varies the lift of the main rotor by increasing or decreasing the pitch of all blades at the same time. It is also used in coordination with cyclic pitch control to regulate the airspeed of the helicopter.