The fore and aft movement of the blade in the plane of rotation is referred to as which term?

The fore and aft movement of the blade in the plane of rotation is referred to as which term?

• A. Blade Lead or Lag
• B. Blade Track
• C. Blade Flap
• D. Blade Span

Answer: (A)

The fore and aft movement of a rotor blade in the plane of rotation is called lead/lag. This motion occurs about the lead-lag hinge, allowing a blade to advance (lead) or retreat (lag) relative to the others as it sweeps around the hub. It helps absorb differences in aerodynamic drag and inertia as the blade moves through the disk, balancing loads and keeping the rotor system smooth. This is different from flap, which is the blade’s vertical motion up and down about the flapping hinge, from blade track, which concerns the blade’s path around the rotor (ensuring all blades follow the same circle), and from blade span, which is simply the blade’s length.

The fore and aft movement of a rotor blade in the plane of rotation is called lead/lag. This motion occurs about the lead-lag hinge, allowing a blade to advance (lead) or retreat (lag) relative to the others as it sweeps around the hub. It helps absorb differences in aerodynamic drag and inertia as the blade moves through the disk, balancing loads and keeping the rotor system smooth. This is different from flap, which is the blade’s vertical motion up and down about the flapping hinge, from blade track, which concerns the blade’s path around the rotor (ensuring all blades follow the same circle), and from blade span, which is simply the blade’s length.