Definition
The angle at which a helicopter's main rotor blades meet the oncoming air, measured between the blade's chord line and the plane of rotation. Adjusting rotor pitch changes the amount of lift each blade produces, which is how a helicopter climbs, descends, and hovers.
Plain English
The angle of the spinning rotor blades. Tilting the blades more steeply makes the helicopter climb; flattening them makes it descend.
Context Anchor
Seen in rotorcraft discussions, especially when learning how helicopter rotor blades produce lift and respond to pilot control inputs.
Derivation
Rotor comes from the Latin rotare, meaning 'to turn.' Pitch in this sense refers to the angle or tilt of a surface relative to the airflow — the same way an aircraft's propeller blades have a pitch angle. So 'rotor pitch' is simply the tilt of the turning blades.
Why Pilots Care
Collective and cyclic controls change rotor pitch to manage lift, climb rate, and direction; incorrect settings can cause loss of control or settling with power.
Intuition Check
Pitch does not mean musical sound here. In rotor pitch, it means the angle setting of the rotor blade as it moves through the air.
Example Sentence 1
The pilot increased rotor pitch on the collective, and the helicopter lifted smoothly off the pad.
Example Sentence 2
Cyclic input varies rotor pitch around the disc so the helicopter moves forward.