Which component prevents the rotor blades from flapping when the rotor head is slowing down or at a complete stop?

• A. Anti-Flap Assemblies
• B. Swashplate Assembly
• C. Hydraulic Dampers
• D. Pitch Control Rods

Answer: (A)

Blade flapping is the up-and-down movement of a rotor blade caused by aerodynamic loads and rotor inertia, which becomes more pronounced as the rotor slows or stops. Anti-flap assemblies are built to limit that motion, providing stops and sometimes damping so the blade cannot flap beyond a small angle when the rotor is decelerating or at rest. This keeps the rotor head stable and reduces the risk of blade strikes or excessive vibration during low RPM conditions. The swashplate handles cyclic pitch changes and does not prevent flap. Hydraulic dampers reduce how quickly flap occurs but do not completely prevent it. Pitch control rods set blade pitch, not flap behavior.