What is the bending upward of rotor blades during flight known as?

The bending upward of rotor blades during flight is known as coning. This phenomenon occurs due to the lift generated by the blades as they rotate, specifically because of aerodynamic forces acting on them. As the rotor blades spin, the centripetal force creates a tendency for the blades to flex outward at the tips. The result is that the blades bend upward, forming a conical shape or cone, which is how the term "coning" is derived.

Understanding coning is crucial in the context of rotorcraft flight dynamics, as it impacts the overall stability and performance of the helicopter. Proper recognition of this behavior is important for pilots and engineers to ensure that the rotor system functions effectively under various flight conditions. In contrast, blade flex refers more generally to the bending of the blades but does not specifically describe the upward coning characteristic. Rotor tilt describes adjustments to the rotor's angle but does not relate directly to blade curvature during lift generation. Lift distortion usually pertains to the alteration of airflow and lift characteristics due to various factors but, again, does not specifically address the upward bending phenomenon inherent to coning.