In a fully articulated rotor system, each blade can freely change pitch and move in which directions?

• A. Only Pitch
• B. Up and Down and Fore and Aft in its plane of rotation
• C. Radially
• D. Across the hub

Answer: (B)

In a fully articulated rotor, each blade is mounted with its own hinges that allow two independent motions within the plane of rotation: flap, which makes the blade rise and fall (up and down), and lead-lag, which lets the blade move fore and aft. This freedom, combined with independent pitch control, lets every blade respond to changing lift across the disk and to dynamic flight forces. Radial movement or movement across the hub aren’t part of the blade’s articulation, so those options don’t fit.