Definition
A helicopter rotor system in which each blade is attached to the rotor hub through mechanical hinges that allow the blade to move independently in three directions: flapping (up and down), lead-lag (forward and backward in the plane of rotation), and feathering (rotation about the blade's long axis to change pitch).
Plain English
A helicopter rotor where every blade is connected to the central hub by hinges, so each blade can move up and down, swing slightly forward and back, and twist to change its angle as it spins.
Context Anchor
Seen in helicopter flight controls, rotor system descriptions, and maintenance discussions.
Derivation
Articulated comes from the Latin articulatus, meaning 'jointed' or 'divided into parts connected by joints.' The same root gives us articulated bus or articulated truck — vehicles built in sections that bend at a joint. An articulated rotor is built the same way: blades joined to the hub through hinges that let them move.
Why Pilots Care
The design reduces stress on the blades and hub by letting them adjust to changing aerodynamic loads in flight.
Analogy
Think of a ceiling fan whose blades are allowed to move at their roots instead of being bolted on completely rigid. The movement is controlled, not loose, and it helps the spinning system adjust to changing forces.
Intuition Check
Articulated does not mean the rotor is loose or floppy. It means the blades have controlled joints that allow specific movements.
Example Sentence 1
The Sikorsky S-76 uses a fully articulated rotor system, with each blade hinged to the hub for flapping, lead-lag, and feathering motion.
Example Sentence 2
In forward flight the articulated rotor let each blade flap upward on the advancing side without overloading the hub.