Definition
A helicopter rotor configuration in which two rotors spin in opposite directions, so that the torque produced by one rotor cancels the torque produced by the other. This arrangement removes the need for a tail rotor to counteract torque.
Plain English
Two rotors that turn in opposite directions on the same helicopter, so their twisting forces cancel each other out instead of trying to spin the fuselage.
Context Anchor
Seen in helicopter and rotorcraft control discussions, especially when explaining how power changes affect direction and control during instrument flight.
Derivation
Counter means opposite or against. Rotating means turning. So the term simply describes two rotors turning against each other. Worth noting because the opposition is the whole point: it is what cancels the torque.
Why Pilots Care
This design removes the power loss and mechanical complexity of a tail rotor, allowing more engine power to be used for lift and improving handling in instrument conditions.
Intuition Check
Counter-rotating does not mean the rotors are fighting each other. It means they are designed to turn in opposite directions so their twisting effects balance each other.
Example Sentence 1
Tandem-rotor helicopters like the Chinook use counter-rotating rotors, so they do not need a tail rotor for torque control.
Example Sentence 2
Because the counter-rotating rotors canceled torque, the pilot did not need to apply pedal pressure to maintain heading during power changes.