Virtually all modern helicopters have a tail rotor which pulls against the torque that comes from the main rotor. This tail rotor also provides additional directional control assistance to the rudder.
Most tail rotors turn at a 3:1 or 6:1 ratio to the main rotor. Meaning, for every revolution of the main rotor, the tail rotor makes 3 revolutions.
You can read more about tail rotors here:
http://en.wikipedia.org/wiki/Tail_rotor
http://www.cybercom.net/~copters/mech/tail_rotors.html
Yes, a helicopter is known as a 'rotary wing aircraft'
No, rotary engines went out of use in aircraft in WW1.
Rotary-Lift Aircraft
Remote control helicopter rotary blades can be fairly dangerous if the helicopter is flying around a person's face. They are often times made of metal, and can damage one's eyes very easily.
Can move in any axis
A rotary winged aircraft or the helicopter
A rotory aircraft is essentially a helicopter or a type of aircraft that relies on the movement of its wing to produce lift.
While airplanes need to be in motion with enough momentum to create enough airspeed for lift off, helicopters can lift off vertically without any momentum of the aircraft. Both aircrafts need a rotary wing. Helicopter wings are rotary and have the capabilities to change the angle or pitch in order to create more or less lift. Airplanes have rotary and fixed wings.
In avionics, a helicopter is known as a Rotary Wing Aircraft. (As distinct from a fixed wing aircraft. ) This indicates the operating principle is based on the ordinary wing profiles used to generate lift.
helicopters fly and have big wirly things on their heads and look like birds The helicopter is an aircraft using rotary wings to give lift and a tail rotor or counter-rotating wings to give stability.
Helicopters are "rotary wing" aircraft- their wings are the rotor blades. Instead of deriving lift from moving air over the fixed wings of an airplane, a helicopter derives lift by moving the wings through the air.
An angular momentum is the vector product which describes the rotary inertia of a system around its axis and is conserved in a closed system.