How it Works

DIRECTION:
Rotorhead and Transmission

The helicopter has two turboshaft engines. These drive the main transmission which turns the rotorhead. The main rotor blades are connected to the rotorhead. As the blades sweep through the air, they form what is called the "rotor disc”. The rotorhead is controlled by a swashplate that transfers pilot inputs to the pitch control rods on the rotor blades. By increasing or decreasing the pitch of the rotor blades, the pilot can control the tilt of the rotor disc to achieve the desired direction for the helicopter to hover or turn or go forwards, backwards, climb or descend.

CONTROL:
Pilot and controls

The pilot uses three controls to fly the helicopter:

A cyclic control stick tilts the rotor disc in the desired direction and controls speed. To turn, the pilot pushes the cyclic control left or right.

The collective pitch lever connects to the swashplate and changes the pitch of the rotor blades in unison. This enables the helicopter to climb or descend.

Foot pedals connected to the tail rotor blades' control arms work together with the cyclic to make left or right turns.

LIFT:
Airfoil

The rotor blades have an airfoil shape, like the wing of an airplane: curved on top and flat on the bottom. When they rotate, the pressure of the slower-moving air flowing under the blade is greater than the faster-moving air above it. This difference in pressure pushes the blades up, giving the helicopter the lift it needs to fly.

BALANCE:
Tail rotor

If a helicopter didn't have a tail rotor, the torque would force the fuselage (body) to rotate in the opposite direction of the spinning rotor blades. The tail rotor compensates for this by providing lateral thrust in the opposite direction, holding the fuselage stationary.

How it Maneuvers

Changing the angle or tilt of the helicopter's rotor blades tells the aircraft whether to move forward or backward or to hover motionless in the air.

FORWARD

In flight, the pilot pushes the cyclic forward which, in turn tilts the rotor disk forward. This tilts the nose of the helicopter down and pushes the helicopter forwards.

TAKEOFF AND HOVER

Keeping the rotor disc level, the pilot pulls on the collective, which increases the pitch in the rotor blades equally until the helicopter rises. To hover, the pilot constantly adjusts the controls to maintain height, position and direction.