What main rotor component restrains lead and lag?

• A. Swashplate
• B. Dampers
• C. Pitch Control Rods
• D. Tail Rotor Head

Answer: (B)

Lead and lag describe the blade’s motion in the plane of rotation relative to the hub. As a blade moves due to inertia and aerodynamic loads, it tends to swing ahead of or behind the hub. The damper assembly inside the rotor head provides resistance to that in-plane motion, damping the lead–lag oscillations and preventing excessive movement, vibration, or binding. The swashplate handles cyclic and collective pitch input, not the in-plane restraint. Pitch control rods set blade pitch, and the tail rotor head handles anti-torque at the tail. So the dampers are the component that restrain lead and lag.