Rotor blade coning is a compromise between which two forces?

Rotor blade coning is a compromise between which two forces?

• A. Drag and thrust
• B. Weight and buoyancy
• C. Lift and centrifugal force
• D. Inertia and gravity

Answer: (C)

Coning results from the blade’s lift trying to tilt the blade tip upward while the rotation pulls the blade outward through centrifugal force. In a steady coning angle, these two effects balance so the blade sits at a constant tilt relative to the plane of rotation. The mathematical intuition is tan(coning) ≈ L / F_c, with L being the lift on the blade and F_c the outward centrifugal force mω^2r. So increasing lift increases the cone angle, while higher centrifugal force (from greater speed or longer blade radius) tends to flatten the cone. Gravity and inertia are present, but the steady coning is governed mainly by lift versus centrifugal force.

Coning results from the blade’s lift trying to tilt the blade tip upward while the rotation pulls the blade outward through centrifugal force. In a steady coning angle, these two effects balance so the blade sits at a constant tilt relative to the plane of rotation. The mathematical intuition is tan(coning) ≈ L / F_c, with L being the lift on the blade and F_c the outward centrifugal force mω^2r. So increasing lift increases the cone angle, while higher centrifugal force (from greater speed or longer blade radius) tends to flatten the cone. Gravity and inertia are present, but the steady coning is governed mainly by lift versus centrifugal force.