An engine usually more than one which is connected to a main driveshaft then that is connected to a C-box or Combining gear box which connects to a transmission which turns the rotors.
The rotor blades lift helicopters
rotor
sam bells
Older helicopters had noisy rotor blades, modern ones are very quiet.
No!
Helicopters have rotors airplanes have propellers
Its Spins The Helicopters Wings
The rotor blade is the airfoil on helicopters.
That is to stabilise the inherent spin of the main rotor and to steer the machine.
It is the major part of the rotor. Helicopters can have 3 up to 8 blades on a rotor.
Yes, many small helicopters have 3 blades
when the main blade rotates it creates torque and if that torque is not countered by the rear rotor the helicopter will spin out and crash. the helicopters that do not have a rear rotor have another rotor that is the same size moving in the opposite direction