The retreating half of the disc has a blade tip speed of 300 MPH minus the 100 MPH indicated forward speed of 200 MPH, and velocity squared is 40,000. In this example the advancing blade creates four times as much lift as the retreating blade. The horsepower loading factor is used in determining rotor system design and testing. This permits the rotor disc to tilt, providing directional control in flight. It also controls the required lift on each blade when in contact with dissymmetry of lift.
Some hubs have droop stops to limit downward movement at low rotor speed.
Coning is the result of lift and centrifugal force acting on a blade in flight. Coning is often expressed as an angle. Helicopter manufacturers determine the coning angle mathematically and build a precone angle into the rotor hub that is similar to the coning effect in normal flight. The preconed hub lets the blades operate at normal coning angles without bending, which reduces stress. It is not necessary to precone the articulated rotor hub because the blade can flap up on horizontal hinges to the correct coning angle.