Figure 2-15.  Relative wind. Figure 2-16.  Horizontal component of relative wind. Figure 2-17.  Induced flow. Figure 2-18.  Normal induced flow velocities along the blade span  during hovering flight. Downward velocity is highest at the blade  tip where blade speed is highest. As blade speed decreases nearer  the center of the disk, downward velocity is less. 2-10 Results in Results in Results in Relative wind Relative wind Relative wind Airfoil direction Airfoil direction Airfoil direction Relative wind Airfoil direction Relative wind Airfoil direction 387 290 183 96 Airspeed knots Axis of rotation