i understand that a helicopter has rotors on top to lift it off the ground?

Question

a small propeller atthe back to stop the helicopter spinning round uncontrobally but what makes it go forwards and backwards?

Answer 1

There are three major control functions in a helicopter that allow the pilot to maneuver the aircraft.

1. Collective - this is usually configured like a big hand-brake lever. Pulling UP on the collective increases the pitch angle of the blades and lifts the helicopter up. Pushing DOWN on the collective decreases the pitch on the blades allowing the helicopter to go down. The collective also has the throttle on the end, much like a mototcycle throttle, it controls the RPM of the blades. This is usually set just before takeoff and a "constant RPM" control engaged to keep the blades turning at the same speed under different load conditions.

2. Cyclic - This is the stick in front of the pilot. It operates like a joy-stick. When the cyclic is moved, the main roter blades tilt in the direction of the movement and cause the helicopter to move in that direction.

3. Rudder pedals - These control the pitch of the tail rotor blades. The main rotor torque is always trying to turn the helicopter body opposite to it's direction of rotation. When the rudder pedals are centered, the tail rotor provides just enough force to keep the helicopter straight. As the pedals are pushed either the tail rotor pich decreases (allowing the main rotor torque to turn the helicopter) or increases the pitch (providing more thrust opposite to the torque effect.)

Incidentally, helicopters don't really fly, the earth rejects them!

Answer 2

A lot of good and correct answers. One way to help understand it is to compare a helicopter to an airplane.

On an airplane you have wings. They provide the lift. You also have engines...pure jet or propeller. They provide the thrust to move forward.

On a helicopter, the main rotor blades provide BOTH the lift and the thrust. By angling the rotor "disk" the blades act as the wing AND the propeller. (For all practical purposes, the actual engines of a helicopter do not provide any thrust for moving forward...they simply operate the main and tail rotors.)

(I'm a helicopter pilot.)

Answer 3

The "stick" in front of the pilot is called the "cyclic" control and it alters the angle of the main rotor head allowing a small amount of the lifting force to be directed in a chosen direction. This allows the aircraft to move forwards, backwards or sideways with ease.

Answer 4

The rotors are attached using a type of CV (constant velocity) joint, called a swashplate, which is connected to rods (called control arms) to control the tilt of the rotors and therefore give directional (as opposed to just upward) flight.

Hope this helps

Answer 5

Angling the rotor disc forward or backward. Tilting it to the side steers the aircraft.

Answer 6

It's the main rotor inclination in any direction, corresponding to stick's moving that make direction changing of an helicopter.
To lift up you have to increase engine power and main rotor blades' pitch pulling up the collective bar, then you move the stick to pitch main rotor spinning plane into desired direction.

Answer 7

ok to keep it simple, when the pilot of the helicopter moves the steering handle forward, then the blades on the top actually tilt and can go at different angles.

Answer 8

The pilot "tilts" the chopper forward to make it go forward, and backward to make it go backward, and holds it level to make it hover. It's all done by manipulating the rotor shaft.

Answer 9

The tilt of the rotor blades

Answer 10

if you notice on the main rotor you will see linkage that lets the blades tilt when the pilot pulls back on the stick makes the blades tilt