Definition
The assembly of rotating blades, hub, and associated control components on a helicopter that produces lift and thrust by spinning through the air. The rotor system also provides directional control by changing blade pitch, allowing the helicopter to climb, descend, hover, and move in any direction.
Plain English
The spinning blades on top of a helicopter, plus the hub they attach to and the parts that control them. This whole setup is what lifts the helicopter and lets the pilot steer it.
Context Anchor
Seen in helicopter and rotorcraft discussions, especially when learning how lift, control, vibration, and preflight inspection relate to the rotating blades.
Derivation
Rotor comes from the Latin 'rotare,' meaning 'to turn' or 'to rotate.' The name simply describes what the system does -- it rotates to do its job.
Why Pilots Care
It supplies all lift and most flight control in a helicopter, so any malfunction directly affects safety and handling.
Intuition Check
Do not read rotor system as only the visible blades. Here, system means the blades plus the parts that hold them and move them together.
Example Sentence 1
During preflight, the pilot inspected the rotor system for any cracks, loose bolts, or damage to the blades.
Example Sentence 2
The instructor demonstrated how collective input changes the pitch of the entire rotor system.